diff --git a/app/soapbox/actions/__tests__/account-notes.test.ts b/app/soapbox/actions/__tests__/account-notes.test.ts
index 134b0abc7..61e0c20b0 100644
--- a/app/soapbox/actions/__tests__/account-notes.test.ts
+++ b/app/soapbox/actions/__tests__/account-notes.test.ts
@@ -1,18 +1,20 @@
 import { Map as ImmutableMap } from 'immutable';
 
 import { __stub } from 'soapbox/api';
-import { mockStore } from 'soapbox/jest/test-helpers';
-import rootReducer from 'soapbox/reducers';
+import { mockStore, rootState } from 'soapbox/jest/test-helpers';
+import { ReducerRecord, EditRecord } from 'soapbox/reducers/account_notes';
 
-import { normalizeAccount } from '../../normalizers';
+import { normalizeAccount, normalizeRelationship } from '../../normalizers';
 import { changeAccountNoteComment, initAccountNoteModal, submitAccountNote } from '../account-notes';
 
+import type { Account } from 'soapbox/types/entities';
+
 describe('submitAccountNote()', () => {
-  let store;
+  let store: ReturnType<typeof mockStore>;
 
   beforeEach(() => {
-    const state = rootReducer(undefined, {})
-      .set('account_notes', { edit: { account: 1, comment: 'hello' } });
+    const state = rootState
+      .set('account_notes', ReducerRecord({ edit: EditRecord({ account: '1', comment: 'hello' }) }));
     store = mockStore(state);
   });
 
@@ -60,11 +62,11 @@ describe('submitAccountNote()', () => {
 });
 
 describe('initAccountNoteModal()', () => {
-  let store;
+  let store: ReturnType<typeof mockStore>;
 
   beforeEach(() => {
-    const state = rootReducer(undefined, {})
-      .set('relationships', ImmutableMap({ 1: { note: 'hello' } }));
+    const state = rootState
+      .set('relationships', ImmutableMap({ '1': normalizeRelationship({ note: 'hello' }) }));
     store = mockStore(state);
   });
 
@@ -75,7 +77,7 @@ describe('initAccountNoteModal()', () => {
       display_name: 'Justin L',
       avatar: 'test.jpg',
       verified: true,
-    });
+    }) as Account;
     const expectedActions = [
       { type: 'ACCOUNT_NOTE_INIT_MODAL', account, comment: 'hello' },
       { type: 'MODAL_OPEN', modalType: 'ACCOUNT_NOTE' },
@@ -88,10 +90,10 @@ describe('initAccountNoteModal()', () => {
 });
 
 describe('changeAccountNoteComment()', () => {
-  let store;
+  let store: ReturnType<typeof mockStore>;
 
   beforeEach(() => {
-    const state = rootReducer(undefined, {});
+    const state = rootState;
     store = mockStore(state);
   });
 
diff --git a/app/soapbox/actions/__tests__/accounts.test.ts b/app/soapbox/actions/__tests__/accounts.test.ts
index dcfeabcf1..0793e36f7 100644
--- a/app/soapbox/actions/__tests__/accounts.test.ts
+++ b/app/soapbox/actions/__tests__/accounts.test.ts
@@ -1,10 +1,10 @@
 import { Map as ImmutableMap } from 'immutable';
 
 import { __stub } from 'soapbox/api';
-import { mockStore } from 'soapbox/jest/test-helpers';
-import rootReducer from 'soapbox/reducers';
+import { mockStore, rootState } from 'soapbox/jest/test-helpers';
+import { ListRecord, ReducerRecord } from 'soapbox/reducers/user_lists';
 
-import { normalizeAccount } from '../../normalizers';
+import { normalizeAccount, normalizeInstance, normalizeRelationship } from '../../normalizers';
 import {
   authorizeFollowRequest,
   blockAccount,
@@ -28,7 +28,7 @@ import {
   unsubscribeAccount,
 } from '../accounts';
 
-let store;
+let store: ReturnType<typeof mockStore>;
 
 describe('createAccount()', () => {
   const params = {
@@ -37,7 +37,7 @@ describe('createAccount()', () => {
 
   describe('with a successful API request', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {});
+      const state = rootState;
       store = mockStore(state);
 
       __stub((mock) => {
@@ -74,10 +74,10 @@ describe('fetchAccount()', () => {
         avatar: 'test.jpg',
       });
 
-      const state = rootReducer(undefined, {})
+      const state = rootState
         .set('accounts', ImmutableMap({
           [id]: account,
-        }));
+        }) as any);
 
       store = mockStore(state);
 
@@ -98,7 +98,7 @@ describe('fetchAccount()', () => {
     const account = require('soapbox/__fixtures__/pleroma-account.json');
 
     beforeEach(() => {
-      const state = rootReducer(undefined, {});
+      const state = rootState;
       store = mockStore(state);
 
       __stub((mock) => {
@@ -125,7 +125,7 @@ describe('fetchAccount()', () => {
 
   describe('with an unsuccessful API request', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {});
+      const state = rootState;
       store = mockStore(state);
 
       __stub((mock) => {
@@ -155,7 +155,7 @@ describe('fetchAccount()', () => {
 describe('fetchAccountByUsername()', () => {
   const id = '123';
   const username = 'tiger';
-  let state, account;
+  let state, account: any;
 
   beforeEach(() => {
     account = normalizeAccount({
@@ -166,7 +166,7 @@ describe('fetchAccountByUsername()', () => {
       birthday: undefined,
     });
 
-    state = rootReducer(undefined, {})
+    state = rootState
       .set('accounts', ImmutableMap({
         [id]: account,
       }));
@@ -180,15 +180,15 @@ describe('fetchAccountByUsername()', () => {
 
   describe('when "accountByUsername" feature is enabled', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {})
-        .set('instance', {
+      const state = rootState
+        .set('instance', normalizeInstance({
           version: '2.7.2 (compatible; Pleroma 2.4.52-1337-g4779199e.gleasonator+soapbox)',
           pleroma: ImmutableMap({
             metadata: ImmutableMap({
               features: [],
             }),
           }),
-        })
+        }))
         .set('me', '123');
       store = mockStore(state);
     });
@@ -243,15 +243,15 @@ describe('fetchAccountByUsername()', () => {
 
   describe('when "accountLookup" feature is enabled', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {})
-        .set('instance', {
+      const state = rootState
+        .set('instance', normalizeInstance({
           version: '3.4.1 (compatible; TruthSocial 1.0.0)',
           pleroma: ImmutableMap({
             metadata: ImmutableMap({
               features: [],
             }),
           }),
-        })
+        }))
         .set('me', '123');
       store = mockStore(state);
     });
@@ -308,7 +308,7 @@ describe('fetchAccountByUsername()', () => {
 
   describe('when using the accountSearch function', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -373,12 +373,12 @@ describe('fetchAccountByUsername()', () => {
 describe('followAccount()', () => {
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
     it('should do nothing', async() => {
-      await store.dispatch(followAccount(1));
+      await store.dispatch(followAccount('1'));
       const actions = store.getActions();
 
       expect(actions).toEqual([]);
@@ -386,10 +386,10 @@ describe('followAccount()', () => {
   });
 
   describe('when logged in', () => {
-    const id = 1;
+    const id = '1';
 
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -460,12 +460,12 @@ describe('followAccount()', () => {
 describe('unfollowAccount()', () => {
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
     it('should do nothing', async() => {
-      await store.dispatch(unfollowAccount(1));
+      await store.dispatch(unfollowAccount('1'));
       const actions = store.getActions();
 
       expect(actions).toEqual([]);
@@ -473,10 +473,10 @@ describe('unfollowAccount()', () => {
   });
 
   describe('when logged in', () => {
-    const id = 1;
+    const id = '1';
 
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -489,7 +489,7 @@ describe('unfollowAccount()', () => {
 
       it('should dispatch the correct actions', async() => {
         const expectedActions = [
-          { type: 'ACCOUNT_UNFOLLOW_REQUEST', id: 1, skipLoading: true },
+          { type: 'ACCOUNT_UNFOLLOW_REQUEST', id: '1', skipLoading: true },
           {
             type: 'ACCOUNT_UNFOLLOW_SUCCESS',
             relationship: { success: true },
@@ -534,11 +534,11 @@ describe('unfollowAccount()', () => {
 });
 
 describe('blockAccount()', () => {
-  const id = 1;
+  const id = '1';
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -552,7 +552,7 @@ describe('blockAccount()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -601,11 +601,11 @@ describe('blockAccount()', () => {
 });
 
 describe('unblockAccount()', () => {
-  const id = 1;
+  const id = '1';
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -619,7 +619,7 @@ describe('unblockAccount()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -667,11 +667,11 @@ describe('unblockAccount()', () => {
 });
 
 describe('muteAccount()', () => {
-  const id = 1;
+  const id = '1';
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -685,7 +685,7 @@ describe('muteAccount()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -734,11 +734,11 @@ describe('muteAccount()', () => {
 });
 
 describe('unmuteAccount()', () => {
-  const id = 1;
+  const id = '1';
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -752,7 +752,7 @@ describe('unmuteAccount()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -800,11 +800,11 @@ describe('unmuteAccount()', () => {
 });
 
 describe('subscribeAccount()', () => {
-  const id = 1;
+  const id = '1';
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -818,7 +818,7 @@ describe('subscribeAccount()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -866,11 +866,11 @@ describe('subscribeAccount()', () => {
 });
 
 describe('unsubscribeAccount()', () => {
-  const id = 1;
+  const id = '1';
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -884,7 +884,7 @@ describe('unsubscribeAccount()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -936,7 +936,7 @@ describe('removeFromFollowers()', () => {
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -950,7 +950,7 @@ describe('removeFromFollowers()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -1002,7 +1002,7 @@ describe('fetchFollowers()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -1059,7 +1059,7 @@ describe('expandFollowers()', () => {
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -1073,28 +1073,28 @@ describe('expandFollowers()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {})
-        .set('user_lists', {
+      const state = rootState
+        .set('user_lists', ReducerRecord({
           followers: ImmutableMap({
-            [id]: {
+            [id]: ListRecord({
               next: 'next_url',
-            },
+            }),
           }),
-        })
+        }))
         .set('me', '123');
       store = mockStore(state);
     });
 
     describe('when the url is null', () => {
       beforeEach(() => {
-        const state = rootReducer(undefined, {})
-          .set('user_lists', {
+        const state = rootState
+          .set('user_lists', ReducerRecord({
             followers: ImmutableMap({
-              [id]: {
+              [id]: ListRecord({
                 next: null,
-              },
+              }),
             }),
-          })
+          }))
           .set('me', '123');
         store = mockStore(state);
       });
@@ -1160,7 +1160,7 @@ describe('fetchFollowing()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
@@ -1217,7 +1217,7 @@ describe('expandFollowing()', () => {
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -1231,28 +1231,28 @@ describe('expandFollowing()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {})
-        .set('user_lists', {
+      const state = rootState
+        .set('user_lists', ReducerRecord({
           following: ImmutableMap({
-            [id]: {
+            [id]: ListRecord({
               next: 'next_url',
-            },
+            }),
           }),
-        })
+        }))
         .set('me', '123');
       store = mockStore(state);
     });
 
     describe('when the url is null', () => {
       beforeEach(() => {
-        const state = rootReducer(undefined, {})
-          .set('user_lists', {
+        const state = rootState
+          .set('user_lists', ReducerRecord({
             following: ImmutableMap({
-              [id]: {
+              [id]: ListRecord({
                 next: null,
-              },
+              }),
             }),
-          })
+          }))
           .set('me', '123');
         store = mockStore(state);
       });
@@ -1318,7 +1318,7 @@ describe('fetchRelationships()', () => {
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -1332,15 +1332,15 @@ describe('fetchRelationships()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {})
+      const state = rootState
         .set('me', '123');
       store = mockStore(state);
     });
 
     describe('without newAccountIds', () => {
       beforeEach(() => {
-        const state = rootReducer(undefined, {})
-          .set('relationships', ImmutableMap({ [id]: {} }))
+        const state = rootState
+          .set('relationships', ImmutableMap({ [id]: normalizeRelationship({}) }))
           .set('me', '123');
         store = mockStore(state);
       });
@@ -1355,7 +1355,7 @@ describe('fetchRelationships()', () => {
 
     describe('with a successful API request', () => {
       beforeEach(() => {
-        const state = rootReducer(undefined, {})
+        const state = rootState
           .set('relationships', ImmutableMap({}))
           .set('me', '123');
         store = mockStore(state);
@@ -1409,7 +1409,7 @@ describe('fetchRelationships()', () => {
 describe('fetchFollowRequests()', () => {
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -1423,14 +1423,14 @@ describe('fetchFollowRequests()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {})
+      const state = rootState
         .set('me', '123');
       store = mockStore(state);
     });
 
     describe('with a successful API request', () => {
       beforeEach(() => {
-        const state = rootReducer(undefined, {})
+        const state = rootState
           .set('relationships', ImmutableMap({}))
           .set('me', '123');
         store = mockStore(state);
@@ -1483,7 +1483,7 @@ describe('fetchFollowRequests()', () => {
 describe('expandFollowRequests()', () => {
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -1497,24 +1497,24 @@ describe('expandFollowRequests()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {})
-        .set('user_lists', {
-          follow_requests: {
+      const state = rootState
+        .set('user_lists', ReducerRecord({
+          follow_requests: ListRecord({
             next: 'next_url',
-          },
-        })
+          }),
+        }))
         .set('me', '123');
       store = mockStore(state);
     });
 
     describe('when the url is null', () => {
       beforeEach(() => {
-        const state = rootReducer(undefined, {})
-          .set('user_lists', {
-            follow_requests: {
+        const state = rootState
+          .set('user_lists', ReducerRecord({
+            follow_requests: ListRecord({
               next: null,
-            },
-          })
+            }),
+          }))
           .set('me', '123');
         store = mockStore(state);
       });
@@ -1579,7 +1579,7 @@ describe('authorizeFollowRequest()', () => {
 
   describe('when logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -1593,7 +1593,7 @@ describe('authorizeFollowRequest()', () => {
 
   describe('when logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '123');
+      const state = rootState.set('me', '123');
       store = mockStore(state);
     });
 
diff --git a/app/soapbox/actions/__tests__/alerts.test.ts b/app/soapbox/actions/__tests__/alerts.test.ts
index f2419893a..5f1f9f4d6 100644
--- a/app/soapbox/actions/__tests__/alerts.test.ts
+++ b/app/soapbox/actions/__tests__/alerts.test.ts
@@ -1,11 +1,10 @@
 import { AxiosError } from 'axios';
 
-import { mockStore } from 'soapbox/jest/test-helpers';
-import rootReducer from 'soapbox/reducers';
+import { mockStore, rootState } from 'soapbox/jest/test-helpers';
 
 import { dismissAlert, showAlert, showAlertForError } from '../alerts';
 
-const buildError = (message: string, status: number) => new AxiosError<any>(message, String(status), null, null, {
+const buildError = (message: string, status: number) => new AxiosError<any>(message, String(status), undefined, null, {
   data: {
     error: message,
   },
@@ -15,10 +14,10 @@ const buildError = (message: string, status: number) => new AxiosError<any>(mess
   config: {},
 });
 
-let store;
+let store: ReturnType<typeof mockStore>;
 
 beforeEach(() => {
-  const state = rootReducer(undefined, {});
+  const state = rootState;
   store = mockStore(state);
 });
 
@@ -28,7 +27,7 @@ describe('dismissAlert()', () => {
     const expectedActions = [
       { type: 'ALERT_DISMISS', alert },
     ];
-    await store.dispatch(dismissAlert(alert));
+    await store.dispatch(dismissAlert(alert as any));
     const actions = store.getActions();
 
     expect(actions).toEqual(expectedActions);
@@ -70,11 +69,10 @@ describe('showAlert()', () => {
     it('dispatches the proper actions', async() => {
       const error = buildError('', 404);
 
-      const expectedActions = [];
       await store.dispatch(showAlertForError(error));
       const actions = store.getActions();
 
-      expect(actions).toEqual(expectedActions);
+      expect(actions).toEqual([]);
     });
   });
 
@@ -82,11 +80,10 @@ describe('showAlert()', () => {
     it('dispatches the proper actions', async() => {
       const error = buildError('', 410);
 
-      const expectedActions = [];
       await store.dispatch(showAlertForError(error));
       const actions = store.getActions();
 
-      expect(actions).toEqual(expectedActions);
+      expect(actions).toEqual([]);
     });
   });
 
diff --git a/app/soapbox/actions/__tests__/blocks.test.ts b/app/soapbox/actions/__tests__/blocks.test.ts
index 2d4832007..8b4c040b3 100644
--- a/app/soapbox/actions/__tests__/blocks.test.ts
+++ b/app/soapbox/actions/__tests__/blocks.test.ts
@@ -1,8 +1,6 @@
-import { Record as ImmutableRecord } from 'immutable';
-
 import { __stub } from 'soapbox/api';
-import { mockStore } from 'soapbox/jest/test-helpers';
-import rootReducer from 'soapbox/reducers';
+import { mockStore, rootState } from 'soapbox/jest/test-helpers';
+import { ListRecord, ReducerRecord as UserListsRecord } from 'soapbox/reducers/user_lists';
 
 import { expandBlocks, fetchBlocks } from '../blocks';
 
@@ -14,11 +12,11 @@ const account = {
 };
 
 describe('fetchBlocks()', () => {
-  let store;
+  let store: ReturnType<typeof mockStore>;
 
   describe('if logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -32,7 +30,7 @@ describe('fetchBlocks()', () => {
 
   describe('if logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '1234');
+      const state = rootState.set('me', '1234');
       store = mockStore(state);
     });
 
@@ -87,11 +85,11 @@ describe('fetchBlocks()', () => {
 });
 
 describe('expandBlocks()', () => {
-  let store;
+  let store: ReturnType<typeof mockStore>;
 
   describe('if logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -105,15 +103,15 @@ describe('expandBlocks()', () => {
 
   describe('if logged in', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', '1234');
+      const state = rootState.set('me', '1234');
       store = mockStore(state);
     });
 
     describe('without a url', () => {
       beforeEach(() => {
-        const state = rootReducer(undefined, {})
+        const state = rootState
           .set('me', '1234')
-          .set('user_lists', ImmutableRecord({ blocks: { next: null } })());
+          .set('user_lists', UserListsRecord({ blocks: ListRecord({ next: null }) }));
         store = mockStore(state);
       });
 
@@ -127,9 +125,9 @@ describe('expandBlocks()', () => {
 
     describe('with a url', () => {
       beforeEach(() => {
-        const state = rootReducer(undefined, {})
+        const state = rootState
           .set('me', '1234')
-          .set('user_lists', ImmutableRecord({ blocks: { next: 'example' } })());
+          .set('user_lists', UserListsRecord({ blocks: ListRecord({ next: 'example' }) }));
         store = mockStore(state);
       });
 
diff --git a/app/soapbox/actions/__tests__/carousels.test.ts b/app/soapbox/actions/__tests__/carousels.test.ts
index 0953b8276..44e4ff0c0 100644
--- a/app/soapbox/actions/__tests__/carousels.test.ts
+++ b/app/soapbox/actions/__tests__/carousels.test.ts
@@ -4,14 +4,14 @@ import { mockStore, rootState } from 'soapbox/jest/test-helpers';
 import { fetchCarouselAvatars } from '../carousels';
 
 describe('fetchCarouselAvatars()', () => {
-  let store;
+  let store: ReturnType<typeof mockStore>;
 
   beforeEach(() => {
     store = mockStore(rootState);
   });
 
   describe('with a successful API request', () => {
-    let avatars;
+    let avatars: Record<string, any>[];
 
     beforeEach(() => {
       avatars = [
diff --git a/app/soapbox/actions/__tests__/compose.test.ts b/app/soapbox/actions/__tests__/compose.test.ts
index 0dd6fc309..6a9ac6e43 100644
--- a/app/soapbox/actions/__tests__/compose.test.ts
+++ b/app/soapbox/actions/__tests__/compose.test.ts
@@ -1,28 +1,29 @@
-import { fromJS } from 'immutable';
+import { Map as ImmutableMap } from 'immutable';
 
-import { mockStore } from 'soapbox/jest/test-helpers';
+import { mockStore, rootState } from 'soapbox/jest/test-helpers';
 import { InstanceRecord } from 'soapbox/normalizers';
-import rootReducer from 'soapbox/reducers';
 
 import { uploadCompose } from '../compose';
 
+import type { IntlShape } from 'react-intl';
+
 describe('uploadCompose()', () => {
   describe('with images', () => {
-    let files, store;
+    let files: FileList, store: ReturnType<typeof mockStore>;
 
     beforeEach(() => {
       const instance = InstanceRecord({
-        configuration: fromJS({
-          statuses: {
+        configuration: ImmutableMap({
+          statuses: ImmutableMap({
             max_media_attachments: 4,
-          },
-          media_attachments: {
+          }),
+          media_attachments: ImmutableMap({
             image_size_limit: 10,
-          },
+          }),
         }),
       });
 
-      const state = rootReducer(undefined, {})
+      const state = rootState
         .set('me', '1234')
         .set('instance', instance);
 
@@ -32,13 +33,13 @@ describe('uploadCompose()', () => {
         name: 'Image',
         size: 15,
         type: 'image/png',
-      }];
+      }] as unknown as FileList;
     });
 
     it('creates an alert if exceeds max size', async() => {
       const mockIntl = {
         formatMessage: jest.fn().mockReturnValue('Image exceeds the current file size limit (10 Bytes)'),
-      };
+      } as unknown as IntlShape;
 
       const expectedActions = [
         { type: 'COMPOSE_UPLOAD_REQUEST', skipLoading: true },
@@ -60,21 +61,21 @@ describe('uploadCompose()', () => {
   });
 
   describe('with videos', () => {
-    let files, store;
+    let files: FileList, store: ReturnType<typeof mockStore>;
 
     beforeEach(() => {
       const instance = InstanceRecord({
-        configuration: fromJS({
-          statuses: {
+        configuration: ImmutableMap({
+          statuses: ImmutableMap({
             max_media_attachments: 4,
-          },
-          media_attachments: {
+          }),
+          media_attachments: ImmutableMap({
             video_size_limit: 10,
-          },
+          }),
         }),
       });
 
-      const state = rootReducer(undefined, {})
+      const state = rootState
         .set('me', '1234')
         .set('instance', instance);
 
@@ -84,13 +85,13 @@ describe('uploadCompose()', () => {
         name: 'Video',
         size: 15,
         type: 'video/mp4',
-      }];
+      }] as unknown as FileList;
     });
 
     it('creates an alert if exceeds max size', async() => {
       const mockIntl = {
         formatMessage: jest.fn().mockReturnValue('Video exceeds the current file size limit (10 Bytes)'),
-      };
+      } as unknown as IntlShape;
 
       const expectedActions = [
         { type: 'COMPOSE_UPLOAD_REQUEST', skipLoading: true },
diff --git a/app/soapbox/actions/__tests__/onboarding.test.ts b/app/soapbox/actions/__tests__/onboarding.test.ts
index cdd268ed5..f786c7f90 100644
--- a/app/soapbox/actions/__tests__/onboarding.test.ts
+++ b/app/soapbox/actions/__tests__/onboarding.test.ts
@@ -1,5 +1,4 @@
-import { mockStore, mockWindowProperty } from 'soapbox/jest/test-helpers';
-import rootReducer from 'soapbox/reducers';
+import { mockStore, mockWindowProperty, rootState } from 'soapbox/jest/test-helpers';
 
 import { checkOnboardingStatus, startOnboarding, endOnboarding } from '../onboarding';
 
@@ -17,7 +16,7 @@ describe('checkOnboarding()', () => {
   it('does nothing if localStorage item is not set', async() => {
     mockGetItem = jest.fn().mockReturnValue(null);
 
-    const state = rootReducer(undefined, { onboarding: { needsOnboarding: false } });
+    const state = rootState.setIn(['onboarding', 'needsOnboarding'], false);
     const store = mockStore(state);
 
     await store.dispatch(checkOnboardingStatus());
@@ -30,7 +29,7 @@ describe('checkOnboarding()', () => {
   it('does nothing if localStorage item is invalid', async() => {
     mockGetItem = jest.fn().mockReturnValue('invalid');
 
-    const state = rootReducer(undefined, { onboarding: { needsOnboarding: false } });
+    const state = rootState.setIn(['onboarding', 'needsOnboarding'], false);
     const store = mockStore(state);
 
     await store.dispatch(checkOnboardingStatus());
@@ -43,7 +42,7 @@ describe('checkOnboarding()', () => {
   it('dispatches the correct action', async() => {
     mockGetItem = jest.fn().mockReturnValue('1');
 
-    const state = rootReducer(undefined, { onboarding: { needsOnboarding: false } });
+    const state = rootState.setIn(['onboarding', 'needsOnboarding'], false);
     const store = mockStore(state);
 
     await store.dispatch(checkOnboardingStatus());
@@ -66,7 +65,7 @@ describe('startOnboarding()', () => {
   });
 
   it('dispatches the correct action', async() => {
-    const state = rootReducer(undefined, { onboarding: { needsOnboarding: false } });
+    const state = rootState.setIn(['onboarding', 'needsOnboarding'], false);
     const store = mockStore(state);
 
     await store.dispatch(startOnboarding());
@@ -89,7 +88,7 @@ describe('endOnboarding()', () => {
   });
 
   it('dispatches the correct action', async() => {
-    const state = rootReducer(undefined, { onboarding: { needsOnboarding: false } });
+    const state = rootState.setIn(['onboarding', 'needsOnboarding'], false);
     const store = mockStore(state);
 
     await store.dispatch(endOnboarding());
diff --git a/app/soapbox/actions/__tests__/statuses.test.ts b/app/soapbox/actions/__tests__/statuses.test.ts
index b206f17b9..18cbc173b 100644
--- a/app/soapbox/actions/__tests__/statuses.test.ts
+++ b/app/soapbox/actions/__tests__/statuses.test.ts
@@ -4,7 +4,6 @@ import { STATUSES_IMPORT } from 'soapbox/actions/importer';
 import { __stub } from 'soapbox/api';
 import { mockStore, rootState } from 'soapbox/jest/test-helpers';
 import { normalizeStatus } from 'soapbox/normalizers/status';
-import rootReducer from 'soapbox/reducers';
 
 import { deleteStatus, fetchContext } from '../statuses';
 
@@ -19,7 +18,7 @@ describe('fetchContext()', () => {
 
     const store = mockStore(rootState);
 
-    store.dispatch(fetchContext('017ed505-5926-392f-256a-f86d5075df70')).then(context => {
+    store.dispatch(fetchContext('017ed505-5926-392f-256a-f86d5075df70')).then(() => {
       const actions = store.getActions();
 
       expect(actions[3].type).toEqual(STATUSES_IMPORT);
@@ -31,11 +30,11 @@ describe('fetchContext()', () => {
 });
 
 describe('deleteStatus()', () => {
-  let store;
+  let store: ReturnType<typeof mockStore>;
 
   describe('if logged out', () => {
     beforeEach(() => {
-      const state = rootReducer(undefined, {}).set('me', null);
+      const state = rootState.set('me', null);
       store = mockStore(state);
     });
 
@@ -54,16 +53,16 @@ describe('deleteStatus()', () => {
     });
 
     beforeEach(() => {
-      const state = rootReducer(undefined, {})
+      const state = rootState
         .set('me', '1234')
         .set('statuses', fromJS({
           [statusId]: cachedStatus,
-        }));
+        }) as any);
       store = mockStore(state);
     });
 
     describe('with a successful API request', () => {
-      let status;
+      let status: any;
 
       beforeEach(() => {
         status = require('soapbox/__fixtures__/pleroma-status-deleted.json');
diff --git a/app/soapbox/components/__tests__/account.test.tsx b/app/soapbox/components/__tests__/account.test.tsx
index e7af7b8f0..7f1458349 100644
--- a/app/soapbox/components/__tests__/account.test.tsx
+++ b/app/soapbox/components/__tests__/account.test.tsx
@@ -5,6 +5,8 @@ import { render, screen } from '../../jest/test-helpers';
 import { normalizeAccount } from '../../normalizers';
 import Account from '../account';
 
+import type { ReducerAccount } from 'soapbox/reducers/accounts';
+
 describe('<Account />', () => {
   it('renders account name and username', () => {
     const account = normalizeAccount({
@@ -12,7 +14,7 @@ describe('<Account />', () => {
       acct: 'justin-username',
       display_name: 'Justin L',
       avatar: 'test.jpg',
-    });
+    }) as ReducerAccount;
 
     const store = {
       accounts: ImmutableMap({
@@ -20,7 +22,7 @@ describe('<Account />', () => {
       }),
     };
 
-    render(<Account account={account} />, null, store);
+    render(<Account account={account} />, undefined, store);
     expect(screen.getByTestId('account')).toHaveTextContent('Justin L');
     expect(screen.getByTestId('account')).toHaveTextContent(/justin-username/i);
   });
@@ -33,7 +35,7 @@ describe('<Account />', () => {
         display_name: 'Justin L',
         avatar: 'test.jpg',
         verified: true,
-      });
+      }) as ReducerAccount;
 
       const store = {
         accounts: ImmutableMap({
@@ -41,7 +43,7 @@ describe('<Account />', () => {
         }),
       };
 
-      render(<Account account={account} />, null, store);
+      render(<Account account={account} />, undefined, store);
       expect(screen.getByTestId('verified-badge')).toBeInTheDocument();
     });
 
@@ -52,7 +54,7 @@ describe('<Account />', () => {
         display_name: 'Justin L',
         avatar: 'test.jpg',
         verified: false,
-      });
+      }) as ReducerAccount;
 
       const store = {
         accounts: ImmutableMap({
@@ -60,7 +62,7 @@ describe('<Account />', () => {
         }),
       };
 
-      render(<Account account={account} />, null, store);
+      render(<Account account={account} />, undefined, store);
       expect(screen.queryAllByTestId('verified-badge')).toHaveLength(0);
     });
   });
diff --git a/app/soapbox/components/__tests__/avatar.test.tsx b/app/soapbox/components/__tests__/avatar.test.tsx
index 55abca520..56f592925 100644
--- a/app/soapbox/components/__tests__/avatar.test.tsx
+++ b/app/soapbox/components/__tests__/avatar.test.tsx
@@ -5,6 +5,8 @@ import { normalizeAccount } from 'soapbox/normalizers';
 import { render, screen } from '../../jest/test-helpers';
 import Avatar from '../avatar';
 
+import type { ReducerAccount } from 'soapbox/reducers/accounts';
+
 describe('<Avatar />', () => {
   const account = normalizeAccount({
     username: 'alice',
@@ -12,7 +14,7 @@ describe('<Avatar />', () => {
     display_name: 'Alice',
     avatar: '/animated/alice.gif',
     avatar_static: '/static/alice.jpg',
-  });
+  }) as ReducerAccount;
 
   const size = 100;
 
diff --git a/app/soapbox/components/__tests__/avatar_overlay.test.tsx b/app/soapbox/components/__tests__/avatar_overlay.test.tsx
index b62d4eef8..105828556 100644
--- a/app/soapbox/components/__tests__/avatar_overlay.test.tsx
+++ b/app/soapbox/components/__tests__/avatar_overlay.test.tsx
@@ -1,25 +1,28 @@
-import { fromJS } from 'immutable';
 import React from 'react';
 
+import { normalizeAccount } from 'soapbox/normalizers';
+
 import { render, screen } from '../../jest/test-helpers';
 import AvatarOverlay from '../avatar_overlay';
 
+import type { ReducerAccount } from 'soapbox/reducers/accounts';
+
 describe('<AvatarOverlay', () => {
-  const account = fromJS({
+  const account = normalizeAccount({
     username: 'alice',
     acct: 'alice',
     display_name: 'Alice',
     avatar: '/animated/alice.gif',
     avatar_static: '/static/alice.jpg',
-  });
+  }) as ReducerAccount;
 
-  const friend = fromJS({
+  const friend = normalizeAccount({
     username: 'eve',
     acct: 'eve@blackhat.lair',
     display_name: 'Evelyn',
     avatar: '/animated/eve.gif',
     avatar_static: '/static/eve.jpg',
-  });
+  }) as ReducerAccount;
 
   it('renders a overlay avatar', () => {
     render(<AvatarOverlay account={account} friend={friend} />);
diff --git a/app/soapbox/components/__tests__/display_name.test.tsx b/app/soapbox/components/__tests__/display_name.test.tsx
index 6d0a05ed5..4c1c1bd23 100644
--- a/app/soapbox/components/__tests__/display_name.test.tsx
+++ b/app/soapbox/components/__tests__/display_name.test.tsx
@@ -5,9 +5,11 @@ import { normalizeAccount } from 'soapbox/normalizers';
 import { render, screen } from '../../jest/test-helpers';
 import DisplayName from '../display-name';
 
+import type { ReducerAccount } from 'soapbox/reducers/accounts';
+
 describe('<DisplayName />', () => {
   it('renders display name + account name', () => {
-    const account = normalizeAccount({ acct: 'bar@baz' });
+    const account = normalizeAccount({ acct: 'bar@baz' }) as ReducerAccount;
     render(<DisplayName account={account} />);
 
     expect(screen.getByTestId('display-name')).toHaveTextContent('bar@baz');
diff --git a/app/soapbox/components/__tests__/emoji_selector.test.tsx b/app/soapbox/components/__tests__/emoji_selector.test.tsx
index 891e3e61c..c680d156e 100644
--- a/app/soapbox/components/__tests__/emoji_selector.test.tsx
+++ b/app/soapbox/components/__tests__/emoji_selector.test.tsx
@@ -6,6 +6,7 @@ import EmojiSelector from '../emoji_selector';
 describe('<EmojiSelector />', () => {
   it('renders correctly', () => {
     const children = <EmojiSelector />;
+    // @ts-ignore
     children.__proto__.addEventListener = () => {};
 
     render(children);
diff --git a/app/soapbox/components/__tests__/quoted-status.test.tsx b/app/soapbox/components/__tests__/quoted-status.test.tsx
index 208a913b2..d57b59b30 100644
--- a/app/soapbox/components/__tests__/quoted-status.test.tsx
+++ b/app/soapbox/components/__tests__/quoted-status.test.tsx
@@ -4,6 +4,8 @@ import { render, screen, rootState } from '../../jest/test-helpers';
 import { normalizeStatus, normalizeAccount } from '../../normalizers';
 import QuotedStatus from '../quoted-status';
 
+import type { ReducerStatus } from 'soapbox/reducers/statuses';
+
 describe('<QuotedStatus />', () => {
   it('renders content', () => {
     const account = normalizeAccount({
@@ -16,11 +18,11 @@ describe('<QuotedStatus />', () => {
       account,
       content: 'hello world',
       contentHtml: 'hello world',
-    });
+    }) as ReducerStatus;
 
-    const state = rootState.setIn(['accounts', '1', account]);
+    const state = rootState.setIn(['accounts', '1'], account);
 
-    render(<QuotedStatus status={status} />, null, state);
+    render(<QuotedStatus status={status} />, undefined, state);
     screen.getByText(/hello world/i);
     expect(screen.getByTestId('quoted-status')).toHaveTextContent(/hello world/i);
   });
diff --git a/app/soapbox/components/__tests__/scroll-top-button.test.tsx b/app/soapbox/components/__tests__/scroll-top-button.test.tsx
index 89518b977..76e6b7c1c 100644
--- a/app/soapbox/components/__tests__/scroll-top-button.test.tsx
+++ b/app/soapbox/components/__tests__/scroll-top-button.test.tsx
@@ -28,7 +28,7 @@ describe('<ScrollTopButton />', () => {
         message={messages.queue}
       />,
     );
-    expect(screen.getByText('Click to see 1 new post', { hidden: true })).toBeInTheDocument();
+    expect(screen.getByText('Click to see 1 new post')).toBeInTheDocument();
 
     render(
       <ScrollTopButton
@@ -38,6 +38,6 @@ describe('<ScrollTopButton />', () => {
         message={messages.queue}
       />,
     );
-    expect(screen.getByText('Click to see 9999999 new posts', { hidden: true })).toBeInTheDocument();
+    expect(screen.getByText('Click to see 9999999 new posts')).toBeInTheDocument();
   });
 });
diff --git a/app/soapbox/components/polls/__tests__/poll-footer.test.tsx b/app/soapbox/components/polls/__tests__/poll-footer.test.tsx
index 7265f7e1c..29c841a0a 100644
--- a/app/soapbox/components/polls/__tests__/poll-footer.test.tsx
+++ b/app/soapbox/components/polls/__tests__/poll-footer.test.tsx
@@ -6,7 +6,7 @@ import { Provider } from 'react-redux';
 import { __stub } from 'soapbox/api';
 import { normalizePoll } from 'soapbox/normalizers/poll';
 
-import { mockStore, render, rootReducer, screen } from '../../../jest/test-helpers';
+import { mockStore, render, screen, rootState } from '../../../jest/test-helpers';
 import PollFooter from '../poll-footer';
 
 let poll = normalizePoll({
@@ -36,7 +36,7 @@ describe('<PollFooter />', () => {
       });
 
       const user = userEvent.setup();
-      const store = mockStore(rootReducer(undefined, {}));
+      const store = mockStore(rootState);
       render(
         <Provider store={store}>
           <IntlProvider locale='en'>
diff --git a/app/soapbox/components/status.tsx b/app/soapbox/components/status.tsx
index 200b2de10..90d7e13df 100644
--- a/app/soapbox/components/status.tsx
+++ b/app/soapbox/components/status.tsx
@@ -84,8 +84,6 @@ interface IStatus extends RouteComponentProps {
   onMoveDown: (statusId: string, featured?: boolean) => void,
   getScrollPosition?: () => ScrollPosition | undefined,
   updateScrollBottom?: (bottom: number) => void,
-  cacheMediaWidth: () => void,
-  cachedMediaWidth: number,
   group: ImmutableMap<string, any>,
   displayMedia: string,
   allowedEmoji: ImmutableList<string>,
diff --git a/app/soapbox/components/ui/datepicker/__tests__/datepicker.test.tsx b/app/soapbox/components/ui/datepicker/__tests__/datepicker.test.tsx
index c4f94c89f..f2db8981c 100644
--- a/app/soapbox/components/ui/datepicker/__tests__/datepicker.test.tsx
+++ b/app/soapbox/components/ui/datepicker/__tests__/datepicker.test.tsx
@@ -30,7 +30,7 @@ describe('<Datepicker />', () => {
     );
 
     let daySelect: HTMLElement;
-    daySelect = document.querySelector('[data-testid="datepicker-day"]');
+    daySelect = document.querySelector('[data-testid="datepicker-day"]') as HTMLElement;
     expect(queryAllByRole(daySelect, 'option')).toHaveLength(29);
 
     await userEvent.selectOptions(
diff --git a/app/soapbox/features/auth_login/components/__tests__/captcha.test.tsx b/app/soapbox/features/auth_login/components/__tests__/captcha.test.tsx
index d48071b0c..bb09d1dba 100644
--- a/app/soapbox/features/auth_login/components/__tests__/captcha.test.tsx
+++ b/app/soapbox/features/auth_login/components/__tests__/captcha.test.tsx
@@ -6,7 +6,7 @@ import CaptchaField, { NativeCaptchaField } from '../captcha';
 
 describe('<CaptchaField />', () => {
   it('renders null by default', () => {
-    render(<CaptchaField />);
+    render(<CaptchaField idempotencyKey='' value='' />);
 
     expect(screen.queryAllByRole('textbox')).toHaveLength(0);
   });
@@ -24,7 +24,9 @@ describe('<NativeCaptchaField />', () => {
     render(
       <NativeCaptchaField
         captcha={captcha}
-        onChange={() => {}} // eslint-disable-line react/jsx-no-bind
+        onChange={() => {}}
+        onClick={() => {}}
+        value=''
       />,
     );
 
diff --git a/app/soapbox/features/auth_login/components/__tests__/login_form.test.tsx b/app/soapbox/features/auth_login/components/__tests__/login_form.test.tsx
index ac1c52930..b46acf31a 100644
--- a/app/soapbox/features/auth_login/components/__tests__/login_form.test.tsx
+++ b/app/soapbox/features/auth_login/components/__tests__/login_form.test.tsx
@@ -13,7 +13,7 @@ describe('<LoginForm />', () => {
       }),
     };
 
-    render(<LoginForm handleSubmit={mockFn} isLoading={false} />, null, store);
+    render(<LoginForm handleSubmit={mockFn} isLoading={false} />, undefined, store);
 
     expect(screen.getByRole('heading')).toHaveTextContent(/sign in/i);
   });
@@ -26,7 +26,7 @@ describe('<LoginForm />', () => {
       }),
     };
 
-    render(<LoginForm handleSubmit={mockFn} isLoading={false} />, null, store);
+    render(<LoginForm handleSubmit={mockFn} isLoading={false} />, undefined, store);
 
     expect(screen.getByRole('heading')).toHaveTextContent(/sign in/i);
   });
diff --git a/app/soapbox/features/auth_login/components/__tests__/login_page.test.tsx b/app/soapbox/features/auth_login/components/__tests__/login_page.test.tsx
index 85daf3e4e..50f94b285 100644
--- a/app/soapbox/features/auth_login/components/__tests__/login_page.test.tsx
+++ b/app/soapbox/features/auth_login/components/__tests__/login_page.test.tsx
@@ -12,7 +12,7 @@ describe('<LoginPage />', () => {
       }),
     };
 
-    render(<LoginPage />, null, store);
+    render(<LoginPage />, undefined, store);
 
     expect(screen.getByRole('heading')).toHaveTextContent('Sign In');
   });
diff --git a/app/soapbox/features/emoji/__tests__/emoji_index.test.ts b/app/soapbox/features/emoji/__tests__/emoji_index.test.ts
index 99f46e3b3..78698981a 100644
--- a/app/soapbox/features/emoji/__tests__/emoji_index.test.ts
+++ b/app/soapbox/features/emoji/__tests__/emoji_index.test.ts
@@ -1,9 +1,10 @@
+// @ts-ignore
 import { emojiIndex } from 'emoji-mart';
 import pick from 'lodash/pick';
 
 import { search } from '../emoji_mart_search_light';
 
-const trimEmojis = emoji => pick(emoji, ['id', 'unified', 'native', 'custom']);
+const trimEmojis = (emoji: any) => pick(emoji, ['id', 'unified', 'native', 'custom']);
 
 describe('emoji_index', () => {
   it('should give same result for emoji_index_light and emoji-mart', () => {
@@ -46,7 +47,7 @@ describe('emoji_index', () => {
   });
 
   it('can include/exclude categories', () => {
-    expect(search('flag', { include: ['people'] })).toEqual([]);
+    expect(search('flag', { include: ['people'] } as any)).toEqual([]);
     expect(emojiIndex.search('flag', { include: ['people'] })).toEqual([]);
   });
 
@@ -63,9 +64,8 @@ describe('emoji_index', () => {
         custom: true,
       },
     ];
-    search('', { custom });
+    search('', { custom } as any);
     emojiIndex.search('', { custom });
-    const expected = [];
     const lightExpected = [
       {
         id: 'mastodon',
@@ -73,7 +73,7 @@ describe('emoji_index', () => {
       },
     ];
     expect(search('masto').map(trimEmojis)).toEqual(lightExpected);
-    expect(emojiIndex.search('masto').map(trimEmojis)).toEqual(expected);
+    expect(emojiIndex.search('masto').map(trimEmojis)).toEqual([]);
   });
 
   it('(different behavior from emoji-mart) erases custom emoji if another is passed', () => {
@@ -89,11 +89,10 @@ describe('emoji_index', () => {
         custom: true,
       },
     ];
-    search('', { custom });
+    search('', { custom } as any);
     emojiIndex.search('', { custom });
-    const expected = [];
-    expect(search('masto', { custom: [] }).map(trimEmojis)).toEqual(expected);
-    expect(emojiIndex.search('masto').map(trimEmojis)).toEqual(expected);
+    expect(search('masto', { custom: [] } as any).map(trimEmojis)).toEqual([]);
+    expect(emojiIndex.search('masto').map(trimEmojis)).toEqual([]);
   });
 
   it('handles custom emoji', () => {
@@ -109,7 +108,7 @@ describe('emoji_index', () => {
         custom: true,
       },
     ];
-    search('', { custom });
+    search('', { custom } as any);
     emojiIndex.search('', { custom });
     const expected = [
       {
@@ -117,15 +116,15 @@ describe('emoji_index', () => {
         custom: true,
       },
     ];
-    expect(search('masto', { custom }).map(trimEmojis)).toEqual(expected);
+    expect(search('masto', { custom } as any).map(trimEmojis)).toEqual(expected);
     expect(emojiIndex.search('masto', { custom }).map(trimEmojis)).toEqual(expected);
   });
 
   it('should filter only emojis we care about, exclude pineapple', () => {
-    const emojisToShowFilter = emoji => emoji.unified !== '1F34D';
-    expect(search('apple', { emojisToShowFilter }).map((obj) => obj.id))
+    const emojisToShowFilter = (emoji: any) => emoji.unified !== '1F34D';
+    expect(search('apple', { emojisToShowFilter } as any).map((obj: any) => obj.id))
       .not.toContain('pineapple');
-    expect(emojiIndex.search('apple', { emojisToShowFilter }).map((obj) => obj.id))
+    expect(emojiIndex.search('apple', { emojisToShowFilter }).map((obj: any) => obj.id))
       .not.toContain('pineapple');
   });
 
diff --git a/app/soapbox/features/feed-filtering/__tests__/feed-carousel.test.tsx b/app/soapbox/features/feed-filtering/__tests__/feed-carousel.test.tsx
index 096682fa0..eb84e7ad0 100644
--- a/app/soapbox/features/feed-filtering/__tests__/feed-carousel.test.tsx
+++ b/app/soapbox/features/feed-filtering/__tests__/feed-carousel.test.tsx
@@ -18,7 +18,7 @@ jest.mock('../../../hooks/useDimensions', () => ({
 };
 
 describe('<FeedCarousel />', () => {
-  let store;
+  let store: any;
 
   describe('with "feedUserFiltering" disabled', () => {
     beforeEach(() => {
@@ -35,7 +35,7 @@ describe('<FeedCarousel />', () => {
     });
 
     it('should render nothing', () => {
-      render(<FeedCarousel />, null, store);
+      render(<FeedCarousel />, undefined, store);
 
       expect(screen.queryAllByTestId('feed-carousel')).toHaveLength(0);
     });
@@ -56,7 +56,7 @@ describe('<FeedCarousel />', () => {
     });
 
     it('should render the Carousel', () => {
-      render(<FeedCarousel />, null, store);
+      render(<FeedCarousel />, undefined, store);
 
       expect(screen.queryAllByTestId('feed-carousel')).toHaveLength(1);
     });
@@ -70,7 +70,7 @@ describe('<FeedCarousel />', () => {
       });
 
       it('renders the error message', () => {
-        render(<FeedCarousel />, null, store);
+        render(<FeedCarousel />, undefined, store);
 
         expect(screen.getByTestId('feed-carousel-error')).toBeInTheDocument();
       });
@@ -110,7 +110,7 @@ describe('<FeedCarousel />', () => {
 
       it('should render the correct prev/next buttons', async() => {
         const user = userEvent.setup();
-        render(<FeedCarousel />, null, store);
+        render(<FeedCarousel />, undefined, store);
 
         await waitFor(() => {
           expect(screen.getByTestId('next-page')).toBeInTheDocument();
diff --git a/app/soapbox/features/landing_page/__tests__/landing_page.test.tsx b/app/soapbox/features/landing_page/__tests__/landing_page.test.tsx
index 02b9a4fe0..a52dbd975 100644
--- a/app/soapbox/features/landing_page/__tests__/landing_page.test.tsx
+++ b/app/soapbox/features/landing_page/__tests__/landing_page.test.tsx
@@ -17,7 +17,7 @@ describe('<LandingPage />', () => {
       },
     });
 
-    render(<LandingPage />, null, state);
+    render(<LandingPage />, undefined, state);
 
     expect(screen.queryByTestId('registrations-open')).toBeInTheDocument();
     expect(screen.queryByTestId('registrations-closed')).not.toBeInTheDocument();
@@ -34,7 +34,7 @@ describe('<LandingPage />', () => {
       },
     });
 
-    render(<LandingPage />, null, state);
+    render(<LandingPage />, undefined, state);
 
     expect(screen.queryByTestId('registrations-closed')).toBeInTheDocument();
     expect(screen.queryByTestId('registrations-open')).not.toBeInTheDocument();
@@ -59,7 +59,7 @@ describe('<LandingPage />', () => {
       },
     }], rootReducer);
 
-    render(<LandingPage />, null, state);
+    render(<LandingPage />, undefined, state);
 
     expect(screen.queryByTestId('registrations-pepe')).toBeInTheDocument();
     expect(screen.queryByTestId('registrations-open')).not.toBeInTheDocument();
@@ -81,7 +81,7 @@ describe('<LandingPage />', () => {
       },
     }], rootReducer);
 
-    render(<LandingPage />, null, state);
+    render(<LandingPage />, undefined, state);
 
     expect(screen.queryByTestId('registrations-closed')).toBeInTheDocument();
     expect(screen.queryByTestId('registrations-pepe')).not.toBeInTheDocument();
diff --git a/app/soapbox/features/notifications/components/__tests__/notification.test.tsx b/app/soapbox/features/notifications/components/__tests__/notification.test.tsx
index 14c43f50c..eacca0f99 100644
--- a/app/soapbox/features/notifications/components/__tests__/notification.test.tsx
+++ b/app/soapbox/features/notifications/components/__tests__/notification.test.tsx
@@ -33,10 +33,12 @@ describe('<Notification />', () => {
 
   describe('grouped notifications', () => {
     it('renders a grouped follow notification for more than 2', async() => {
-      const { notification, state } = normalize(require('soapbox/__fixtures__/notification-follow.json'));
-      const groupedNotification = { ...notification.toJS(), total_count: 5 };
+      const { notification, state } = normalize({
+        ...require('soapbox/__fixtures__/notification-follow.json'),
+        total_count: 5,
+      });
 
-      render(<Notification notification={groupedNotification} />, undefined, state);
+      render(<Notification notification={notification} />, undefined, state);
 
       expect(screen.getByTestId('notification')).toBeInTheDocument();
       expect(screen.getByTestId('account')).toContainHTML('neko@rdrama.cc');
@@ -44,10 +46,12 @@ describe('<Notification />', () => {
     });
 
     it('renders a grouped follow notification for 1', async() => {
-      const { notification, state } = normalize(require('soapbox/__fixtures__/notification-follow.json'));
-      const groupedNotification = { ...notification.toJS(), total_count: 2 };
+      const { notification, state } = normalize({
+        ...require('soapbox/__fixtures__/notification-follow.json'),
+        total_count: 2,
+      });
 
-      render(<Notification notification={groupedNotification} />, undefined, state);
+      render(<Notification notification={notification} />, undefined, state);
 
       expect(screen.getByTestId('notification')).toBeInTheDocument();
       expect(screen.getByTestId('account')).toContainHTML('neko@rdrama.cc');
diff --git a/app/soapbox/features/notifications/components/notification.tsx b/app/soapbox/features/notifications/components/notification.tsx
index dda887919..4b67e5645 100644
--- a/app/soapbox/features/notifications/components/notification.tsx
+++ b/app/soapbox/features/notifications/components/notification.tsx
@@ -128,16 +128,14 @@ const buildMessage = (
 interface INotificaton {
   hidden?: boolean,
   notification: NotificationEntity,
-  onMoveUp: (notificationId: string) => void,
-  onMoveDown: (notificationId: string) => void,
-  onMention: (account: Account) => void,
-  onFavourite: (status: Status) => void,
-  onReblog: (status: Status, e?: KeyboardEvent) => void,
-  onToggleHidden: (status: Status) => void,
+  onMoveUp?: (notificationId: string) => void,
+  onMoveDown?: (notificationId: string) => void,
+  onMention?: (account: Account) => void,
+  onFavourite?: (status: Status) => void,
+  onReblog?: (status: Status, e?: KeyboardEvent) => void,
+  onToggleHidden?: (status: Status) => void,
   getScrollPosition?: () => ScrollPosition | undefined,
   updateScrollBottom?: (bottom: number) => void,
-  cacheMediaWidth: () => void,
-  cachedMediaWidth: number,
   siteTitle?: string,
 }
 
@@ -180,35 +178,39 @@ const Notification: React.FC<INotificaton> = (props) => {
   const handleMention = (e?: KeyboardEvent) => {
     e?.preventDefault();
 
-    if (account && typeof account === 'object') {
+    if (props.onMention && account && typeof account === 'object') {
       props.onMention(account);
     }
   };
 
   const handleHotkeyFavourite = (e?: KeyboardEvent) => {
-    if (status && typeof status === 'object') {
+    if (props.onFavourite && status && typeof status === 'object') {
       props.onFavourite(status);
     }
   };
 
   const handleHotkeyBoost = (e?: KeyboardEvent) => {
-    if (status && typeof status === 'object') {
+    if (props.onReblog && status && typeof status === 'object') {
       props.onReblog(status, e);
     }
   };
 
   const handleHotkeyToggleHidden = (e?: KeyboardEvent) => {
-    if (status && typeof status === 'object') {
+    if (props.onToggleHidden && status && typeof status === 'object') {
       props.onToggleHidden(status);
     }
   };
 
   const handleMoveUp = () => {
-    onMoveUp(notification.id);
+    if (onMoveUp) {
+      onMoveUp(notification.id);
+    }
   };
 
   const handleMoveDown = () => {
-    onMoveDown(notification.id);
+    if (onMoveDown) {
+      onMoveDown(notification.id);
+    }
   };
 
   const renderIcon = (): React.ReactNode => {
@@ -268,8 +270,6 @@ const Notification: React.FC<INotificaton> = (props) => {
             contextType='notifications'
             getScrollPosition={props.getScrollPosition}
             updateScrollBottom={props.updateScrollBottom}
-            cachedMediaWidth={props.cachedMediaWidth}
-            cacheMediaWidth={props.cacheMediaWidth}
           />
         ) : null;
       default:
diff --git a/app/soapbox/features/ui/__tests__/index.test.tsx b/app/soapbox/features/ui/__tests__/index.test.tsx
index 5a3164996..c28c21589 100644
--- a/app/soapbox/features/ui/__tests__/index.test.tsx
+++ b/app/soapbox/features/ui/__tests__/index.test.tsx
@@ -15,12 +15,12 @@ const TestableComponent = () => (
     <Route path='/login' exact><span data-testid='sign-in'>Sign in</span></Route>
 
     {/* WrappedRount will redirect to /login for logged out users... which will resolve to the route above! */}
-    <WrappedRoute path='/notifications' />
+    <WrappedRoute path='/notifications' component={() => null} />
   </Switch>
 );
 
 describe('<UI />', () => {
-  let store;
+  let store: any;
 
   beforeEach(() => {
     store = {
diff --git a/app/soapbox/features/ui/components/__tests__/compose-button.test.tsx b/app/soapbox/features/ui/components/__tests__/compose-button.test.tsx
index 86b9b84bd..c98b7aa50 100644
--- a/app/soapbox/features/ui/components/__tests__/compose-button.test.tsx
+++ b/app/soapbox/features/ui/components/__tests__/compose-button.test.tsx
@@ -1,17 +1,15 @@
 import { fireEvent, render, screen } from '@testing-library/react';
-import { Map as ImmutableMap } from 'immutable';
 import React from 'react';
 import { IntlProvider } from 'react-intl';
 import { Provider } from 'react-redux';
 import '@testing-library/jest-dom';
 
 import { MODAL_OPEN } from 'soapbox/actions/modals';
-import { mockStore } from 'soapbox/jest/test-helpers';
-import rootReducer from 'soapbox/reducers';
+import { mockStore, rootState } from 'soapbox/jest/test-helpers';
 
 import ComposeButton from '../compose-button';
 
-const store = mockStore(rootReducer(ImmutableMap(), {}));
+const store = mockStore(rootState);
 const renderComposeButton = () => {
   render(
     <Provider store={store}>
diff --git a/app/soapbox/features/ui/components/__tests__/cta-banner.test.tsx b/app/soapbox/features/ui/components/__tests__/cta-banner.test.tsx
index cc4c118e6..dbda24b55 100644
--- a/app/soapbox/features/ui/components/__tests__/cta-banner.test.tsx
+++ b/app/soapbox/features/ui/components/__tests__/cta-banner.test.tsx
@@ -14,7 +14,7 @@ describe('<CtaBanner />', () => {
     it('renders empty', () => {
       const store = { me: true };
 
-      render(<CtaBanner />, null, store);
+      render(<CtaBanner />, undefined, store);
       expect(screen.queryAllByTestId('cta-banner')).toHaveLength(0);
     });
   });
@@ -23,7 +23,7 @@ describe('<CtaBanner />', () => {
     it('renders empty', () => {
       const store = { soapbox: ImmutableMap({ singleUserMode: true }) };
 
-      render(<CtaBanner />, null, store);
+      render(<CtaBanner />, undefined, store);
       expect(screen.queryAllByTestId('cta-banner')).toHaveLength(0);
     });
   });
diff --git a/app/soapbox/features/ui/components/__tests__/subscribe-button.test.tsx b/app/soapbox/features/ui/components/__tests__/subscribe-button.test.tsx
index 3dea16d97..d0ec92f96 100644
--- a/app/soapbox/features/ui/components/__tests__/subscribe-button.test.tsx
+++ b/app/soapbox/features/ui/components/__tests__/subscribe-button.test.tsx
@@ -5,7 +5,9 @@ import { render, screen } from '../../../../jest/test-helpers';
 import { normalizeAccount, normalizeRelationship } from '../../../../normalizers';
 import SubscribeButton from '../subscription-button';
 
-let account = {
+import type { ReducerAccount } from 'soapbox/reducers/accounts';
+
+const justin = {
   id: '1',
   acct: 'justin-username',
   display_name: 'Justin L',
@@ -13,13 +15,13 @@ let account = {
 };
 
 describe('<SubscribeButton />', () => {
-  let store;
+  let store: any;
 
   describe('with "accountNotifies" disabled', () => {
     it('renders nothing', () => {
-      account = normalizeAccount({ ...account, relationship: normalizeRelationship({ following: true }) });
+      const account = normalizeAccount({ ...justin, relationship: normalizeRelationship({ following: true }) }) as ReducerAccount;
 
-      render(<SubscribeButton account={account} />, null, store);
+      render(<SubscribeButton account={account} />, undefined, store);
       expect(screen.queryAllByTestId('icon-button')).toHaveLength(0);
     });
   });
diff --git a/app/soapbox/features/ui/components/__tests__/trends-panel.test.tsx b/app/soapbox/features/ui/components/__tests__/trends-panel.test.tsx
index 03ae48553..487a84bfb 100644
--- a/app/soapbox/features/ui/components/__tests__/trends-panel.test.tsx
+++ b/app/soapbox/features/ui/components/__tests__/trends-panel.test.tsx
@@ -23,7 +23,7 @@ describe('<TrendsPanel />', () => {
       })(),
     };
 
-    render(<TrendsPanel limit={1} />, null, store);
+    render(<TrendsPanel limit={1} />, undefined, store);
     expect(screen.getByTestId('hashtag')).toHaveTextContent(/hashtag 1/i);
     expect(screen.getByTestId('hashtag')).toHaveTextContent(/180 people talking/i);
     expect(screen.getByTestId('sparklines')).toBeInTheDocument();
@@ -46,7 +46,7 @@ describe('<TrendsPanel />', () => {
       })(),
     };
 
-    render(<TrendsPanel limit={3} />, null, store);
+    render(<TrendsPanel limit={3} />, undefined, store);
     expect(screen.queryAllByTestId('hashtag')).toHaveLength(2);
   });
 
@@ -67,7 +67,7 @@ describe('<TrendsPanel />', () => {
       })(),
     };
 
-    render(<TrendsPanel limit={1} />, null, store);
+    render(<TrendsPanel limit={1} />, undefined, store);
     expect(screen.queryAllByTestId('hashtag')).toHaveLength(1);
   });
 
@@ -79,7 +79,7 @@ describe('<TrendsPanel />', () => {
       })(),
     };
 
-    render(<TrendsPanel limit={1} />, null, store);
+    render(<TrendsPanel limit={1} />, undefined, store);
     expect(screen.queryAllByTestId('hashtag')).toHaveLength(0);
   });
 });
diff --git a/app/soapbox/features/ui/components/__tests__/who-to-follow-panel.test.tsx b/app/soapbox/features/ui/components/__tests__/who-to-follow-panel.test.tsx
index 56e4f8422..84a645514 100644
--- a/app/soapbox/features/ui/components/__tests__/who-to-follow-panel.test.tsx
+++ b/app/soapbox/features/ui/components/__tests__/who-to-follow-panel.test.tsx
@@ -24,7 +24,7 @@ describe('<WhoToFollow />', () => {
       },
     };
 
-    render(<WhoToFollowPanel limit={1} />, null, store);
+    render(<WhoToFollowPanel limit={1} />, undefined, store);
     expect(screen.getByTestId('account')).toHaveTextContent(/my name/i);
   });
 
@@ -58,7 +58,7 @@ describe('<WhoToFollow />', () => {
       },
     };
 
-    render(<WhoToFollowPanel limit={3} />, null, store);
+    render(<WhoToFollowPanel limit={3} />, undefined, store);
     expect(screen.queryAllByTestId('account')).toHaveLength(2);
   });
 
@@ -92,7 +92,7 @@ describe('<WhoToFollow />', () => {
       },
     };
 
-    render(<WhoToFollowPanel limit={1} />, null, store);
+    render(<WhoToFollowPanel limit={1} />, undefined, store);
     expect(screen.queryAllByTestId('account')).toHaveLength(1);
   });
 
@@ -117,7 +117,7 @@ describe('<WhoToFollow />', () => {
       },
     };
 
-    render(<WhoToFollowPanel limit={1} />, null, store);
+    render(<WhoToFollowPanel limit={1} />, undefined, store);
     expect(screen.queryAllByTestId('account')).toHaveLength(0);
   });
 });
diff --git a/app/soapbox/features/ui/components/modals/report-modal/__tests__/report-modal.test.tsx b/app/soapbox/features/ui/components/modals/report-modal/__tests__/report-modal.test.tsx
index 1fe62d7f2..a2dee08b5 100644
--- a/app/soapbox/features/ui/components/modals/report-modal/__tests__/report-modal.test.tsx
+++ b/app/soapbox/features/ui/components/modals/report-modal/__tests__/report-modal.test.tsx
@@ -9,7 +9,7 @@ import { normalizeAccount, normalizeStatus } from '../../../../../../normalizers
 import ReportModal from '../report-modal';
 
 describe('<ReportModal />', () => {
-  let store;
+  let store: any;
 
   beforeEach(() => {
     const rules = require('soapbox/__fixtures__/rules.json');
diff --git a/app/soapbox/features/verification/__tests__/index.test.tsx b/app/soapbox/features/verification/__tests__/index.test.tsx
index 32182f515..e24aee442 100644
--- a/app/soapbox/features/verification/__tests__/index.test.tsx
+++ b/app/soapbox/features/verification/__tests__/index.test.tsx
@@ -14,7 +14,7 @@ const TestableComponent = () => (
   </Switch>
 );
 
-const renderComponent = (store) => render(
+const renderComponent = (store: any) => render(
   <TestableComponent />,
   {},
   store,
@@ -22,7 +22,7 @@ const renderComponent = (store) => render(
 );
 
 describe('<Verification />', () => {
-  let store;
+  let store: any;
 
   beforeEach(() => {
     store = {
diff --git a/app/soapbox/features/verification/steps/__tests__/age-verification.test.tsx b/app/soapbox/features/verification/steps/__tests__/age-verification.test.tsx
index 7dd835313..f310a0741 100644
--- a/app/soapbox/features/verification/steps/__tests__/age-verification.test.tsx
+++ b/app/soapbox/features/verification/steps/__tests__/age-verification.test.tsx
@@ -8,7 +8,7 @@ import { fireEvent, render, screen } from 'soapbox/jest/test-helpers';
 import AgeVerification from '../age-verification';
 
 describe('<AgeVerification />', () => {
-  let store;
+  let store: any;
 
   beforeEach(() => {
     store = {
diff --git a/app/soapbox/hooks/__tests__/useDimensions.test.ts b/app/soapbox/hooks/__tests__/useDimensions.test.ts
index c437f1394..0adee42e4 100644
--- a/app/soapbox/hooks/__tests__/useDimensions.test.ts
+++ b/app/soapbox/hooks/__tests__/useDimensions.test.ts
@@ -6,7 +6,7 @@ let listener: ((rect: any) => void) | undefined = undefined;
 
 (window as any).ResizeObserver = class ResizeObserver {
 
-  constructor(ls) {
+  constructor(ls: any) {
     listener = ls;
   }
 
@@ -63,7 +63,7 @@ describe('useDimensions()', () => {
       disconnect() {
         disconnect();
       }
-    
+
     };
 
     const { result, unmount } = renderHook(() => useDimensions());
diff --git a/app/soapbox/jest/test-helpers.tsx b/app/soapbox/jest/test-helpers.tsx
index 459049b52..657919b5a 100644
--- a/app/soapbox/jest/test-helpers.tsx
+++ b/app/soapbox/jest/test-helpers.tsx
@@ -1,3 +1,4 @@
+import { configureMockStore } from '@jedmao/redux-mock-store';
 import { render, RenderOptions } from '@testing-library/react';
 import { merge } from 'immutable';
 import React, { FC, ReactElement } from 'react';
@@ -5,18 +6,19 @@ import { IntlProvider } from 'react-intl';
 import { Provider } from 'react-redux';
 import { MemoryRouter } from 'react-router-dom';
 import { Action, applyMiddleware, createStore } from 'redux';
-import configureMockStore from 'redux-mock-store';
 import thunk from 'redux-thunk';
 import '@testing-library/jest-dom';
 
 import NotificationsContainer from '../features/ui/containers/notifications_container';
 import { default as rootReducer } from '../reducers';
 
+import type { AnyAction } from 'redux';
+import type { AppDispatch } from 'soapbox/store';
+
 // Mock Redux
 // https://redux.js.org/recipes/writing-tests/
-const middlewares = [thunk];
-const mockStore = configureMockStore(middlewares);
-let rootState = rootReducer(undefined, {} as Action);
+const rootState = rootReducer(undefined, {} as Action);
+const mockStore = configureMockStore<typeof rootState, AnyAction, AppDispatch>([thunk]);
 
 /** Apply actions to the state, one at a time. */
 const applyActions = (state: any, actions: any, reducer: any) => {
@@ -26,13 +28,14 @@ const applyActions = (state: any, actions: any, reducer: any) => {
 const createTestStore = (initialState: any) => createStore(rootReducer, initialState, applyMiddleware(thunk));
 
 const TestApp: FC<any> = ({ children, storeProps, routerProps = {} }) => {
-  let store: any;
+  let store: ReturnType<typeof createTestStore>;
+  let appState = rootState;
 
   if (storeProps) {
-    rootState = merge(rootState, storeProps);
-    store = createTestStore(rootState);
+    appState = merge(rootState, storeProps);
+    store = createTestStore(appState);
   } else {
-    store = createTestStore(rootState);
+    store = createTestStore(appState);
   }
 
   const props = {
diff --git a/app/soapbox/normalizers/__tests__/account.test.ts b/app/soapbox/normalizers/__tests__/account.test.ts
index 761b2fac5..b5f4f5a75 100644
--- a/app/soapbox/normalizers/__tests__/account.test.ts
+++ b/app/soapbox/normalizers/__tests__/account.test.ts
@@ -154,9 +154,9 @@ describe('normalizeAccount()', () => {
     const result = normalizeAccount(account);
     const field = result.fields.get(1);
 
-    expect(field.name_emojified).toBe('Soapbox <img draggable="false" class="emojione" alt=":ablobcatrainbow:" title=":ablobcatrainbow:" src="https://gleasonator.com/emoji/blobcat/ablobcatrainbow.png" />');
-    expect(field.value_emojified).toBe('<a href="https://soapbox.pub" rel="ugc">https://soapbox.pub</a> <img draggable="false" class="emojione" alt=":soapbox:" title=":soapbox:" src="https://gleasonator.com/emoji/Gleasonator/soapbox.png" />');
-    expect(field.value_plain).toBe('https://soapbox.pub :soapbox:');
+    expect(field?.name_emojified).toBe('Soapbox <img draggable="false" class="emojione" alt=":ablobcatrainbow:" title=":ablobcatrainbow:" src="https://gleasonator.com/emoji/blobcat/ablobcatrainbow.png" />');
+    expect(field?.value_emojified).toBe('<a href="https://soapbox.pub" rel="ugc">https://soapbox.pub</a> <img draggable="false" class="emojione" alt=":soapbox:" title=":soapbox:" src="https://gleasonator.com/emoji/Gleasonator/soapbox.png" />');
+    expect(field?.value_plain).toBe('https://soapbox.pub :soapbox:');
   });
 
   it('adds default avatar and banner to GoToSocial account', () => {
diff --git a/app/soapbox/normalizers/__tests__/poll.test.ts b/app/soapbox/normalizers/__tests__/poll.test.ts
index 31691f484..8acf2ece4 100644
--- a/app/soapbox/normalizers/__tests__/poll.test.ts
+++ b/app/soapbox/normalizers/__tests__/poll.test.ts
@@ -38,11 +38,11 @@ describe('normalizePoll()', () => {
     const result = normalizePoll(poll);
 
     // Emojifies poll options
-    expect(result.options.get(1).title_emojified)
+    expect(result.options.get(1)?.title_emojified)
       .toEqual('Custom emoji <img draggable="false" class="emojione" alt=":gleason_excited:" title=":gleason_excited:" src="https://gleasonator.com/emoji/gleason_emojis/gleason_excited.png" /> ');
 
     // Parses emojis as Immutable.Record's
     expect(ImmutableRecord.isRecord(result.emojis.get(0))).toBe(true);
-    expect(result.emojis.get(1).shortcode).toEqual('soapbox');
+    expect(result.emojis.get(1)?.shortcode).toEqual('soapbox');
   });
 });
diff --git a/app/soapbox/normalizers/__tests__/status.test.ts b/app/soapbox/normalizers/__tests__/status.test.ts
index ac9358f51..43336d00f 100644
--- a/app/soapbox/normalizers/__tests__/status.test.ts
+++ b/app/soapbox/normalizers/__tests__/status.test.ts
@@ -2,6 +2,8 @@ import { Record as ImmutableRecord, fromJS } from 'immutable';
 
 import { normalizeStatus } from '../status';
 
+import type { Poll, Card } from 'soapbox/types/entities';
+
 describe('normalizeStatus()', () => {
   it('adds base fields', () => {
     const status = {};
@@ -42,8 +44,8 @@ describe('normalizeStatus()', () => {
     const result = normalizeStatus(status).mentions;
 
     expect(result.size).toBe(1);
-    expect(result.get(0).toJS()).toMatchObject(expected);
-    expect(result.get(0).id).toEqual('106801667066418367');
+    expect(result.get(0)?.toJS()).toMatchObject(expected);
+    expect(result.get(0)?.id).toEqual('106801667066418367');
     expect(ImmutableRecord.isRecord(result.get(0))).toBe(true);
   });
 
@@ -101,8 +103,7 @@ describe('normalizeStatus()', () => {
     const result = normalizeStatus(status).media_attachments;
 
     expect(result.size).toBe(4);
-    expect(result.get(0).text_url).toBe(undefined);
-    expect(result.get(1).meta).toEqual(fromJS({}));
+    expect(result.get(1)?.meta).toEqual(fromJS({}));
     expect(result.getIn([1, 'pleroma', 'mime_type'])).toBe('application/x-nes-rom');
     expect(ImmutableRecord.isRecord(result.get(3))).toBe(true);
   });
@@ -147,6 +148,7 @@ describe('normalizeStatus()', () => {
   it('normalizes poll and poll options', () => {
     const status = { poll: { options: [{ title: 'Apples' }] } };
     const result = normalizeStatus(status);
+    const poll = result.poll as Poll;
 
     const expected = {
       options: [{ title: 'Apples', votes_count: 0 }],
@@ -159,46 +161,49 @@ describe('normalizeStatus()', () => {
       voted: false,
     };
 
-    expect(ImmutableRecord.isRecord(result.poll)).toBe(true);
-    expect(ImmutableRecord.isRecord(result.poll.options.get(0))).toBe(true);
-    expect(result.poll.toJS()).toMatchObject(expected);
-    expect(result.poll.expires_at instanceof Date).toBe(true);
+    expect(ImmutableRecord.isRecord(poll)).toBe(true);
+    expect(ImmutableRecord.isRecord(poll.options.get(0))).toBe(true);
+    expect(poll.toJS()).toMatchObject(expected);
+    expect(poll.expires_at instanceof Date).toBe(true);
   });
 
   it('normalizes a Pleroma logged-out poll', () => {
     const status = require('soapbox/__fixtures__/pleroma-status-with-poll.json');
     const result = normalizeStatus(status);
+    const poll = result.poll as Poll;
 
     // Adds logged-in fields
-    expect(result.poll.voted).toBe(false);
-    expect(result.poll.own_votes).toBe(null);
+    expect(poll.voted).toBe(false);
+    expect(poll.own_votes).toBe(null);
   });
 
   it('normalizes poll with emojis', () => {
     const status = require('soapbox/__fixtures__/pleroma-status-with-poll-with-emojis.json');
     const result = normalizeStatus(status);
+    const poll = result.poll as Poll;
 
     // Emojifies poll options
-    expect(result.poll.options.get(1).title_emojified)
+    expect(poll.options.get(1)?.title_emojified)
       .toEqual('Custom emoji <img draggable="false" class="emojione" alt=":gleason_excited:" title=":gleason_excited:" src="https://gleasonator.com/emoji/gleason_emojis/gleason_excited.png" /> ');
 
     // Parses emojis as Immutable.Record's
-    expect(ImmutableRecord.isRecord(result.poll.emojis.get(0))).toBe(true);
-    expect(result.poll.emojis.get(1).shortcode).toEqual('soapbox');
+    expect(ImmutableRecord.isRecord(poll.emojis.get(0))).toBe(true);
+    expect(poll.emojis.get(1)?.shortcode).toEqual('soapbox');
   });
 
   it('normalizes a card', () => {
     const status = require('soapbox/__fixtures__/status-with-card.json');
     const result = normalizeStatus(status);
+    const card = result.card as Card;
 
-    expect(ImmutableRecord.isRecord(result.card)).toBe(true);
-    expect(result.card.type).toEqual('link');
-    expect(result.card.provider_url).toEqual('https://soapbox.pub');
+    expect(ImmutableRecord.isRecord(card)).toBe(true);
+    expect(card.type).toEqual('link');
+    expect(card.provider_url).toEqual('https://soapbox.pub');
   });
 
   it('preserves Truth Social external_video_id', () => {
     const status = require('soapbox/__fixtures__/truthsocial-status-with-external-video.json');
     const result = normalizeStatus(status);
-    expect(result.media_attachments.get(0).external_video_id).toBe('vwfnq9');
+    expect(result.media_attachments.get(0)?.external_video_id).toBe('vwfnq9');
   });
 });
diff --git a/app/soapbox/normalizers/soapbox/__tests__/soapbox_config-test.ts b/app/soapbox/normalizers/soapbox/__tests__/soapbox_config-test.ts
index 65c4291f8..e48198ecc 100644
--- a/app/soapbox/normalizers/soapbox/__tests__/soapbox_config-test.ts
+++ b/app/soapbox/normalizers/soapbox/__tests__/soapbox_config-test.ts
@@ -32,6 +32,6 @@ describe('normalizeSoapboxConfig()', () => {
     const result = normalizeSoapboxConfig(require('soapbox/__fixtures__/spinster-soapbox.json'));
     expect(ImmutableRecord.isRecord(result.promoPanel)).toBe(true);
     expect(ImmutableRecord.isRecord(result.promoPanel.items.get(0))).toBe(true);
-    expect(result.promoPanel.items.get(2).icon).toBe('question-circle');
+    expect(result.promoPanel.items.get(2)?.icon).toBe('question-circle');
   });
 });
diff --git a/app/soapbox/reducers/__tests__/accounts.test.ts b/app/soapbox/reducers/__tests__/accounts.test.ts
index 647bb676a..02baa6d92 100644
--- a/app/soapbox/reducers/__tests__/accounts.test.ts
+++ b/app/soapbox/reducers/__tests__/accounts.test.ts
@@ -23,7 +23,7 @@ describe('accounts reducer', () => {
       const action = { type: ACCOUNT_IMPORT, account };
       const result = reducer(undefined, action).get('106801667066418367');
 
-      expect(result.moved).toBe('107945464165013501');
+      expect(result?.moved).toBe('107945464165013501');
     });
   });
 });
diff --git a/app/soapbox/reducers/__tests__/alerts.test.ts b/app/soapbox/reducers/__tests__/alerts.test.ts
index 306ab2fcd..441cf2d8d 100644
--- a/app/soapbox/reducers/__tests__/alerts.test.ts
+++ b/app/soapbox/reducers/__tests__/alerts.test.ts
@@ -11,7 +11,7 @@ import reducer from '../alerts';
 
 describe('alerts reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableList());
+    expect(reducer(undefined, {} as any)).toEqual(ImmutableList());
   });
 
   describe('ALERT_SHOW', () => {
diff --git a/app/soapbox/reducers/__tests__/carousels.test.ts b/app/soapbox/reducers/__tests__/carousels.test.ts
index 45e87c8ff..2745b078d 100644
--- a/app/soapbox/reducers/__tests__/carousels.test.ts
+++ b/app/soapbox/reducers/__tests__/carousels.test.ts
@@ -19,7 +19,7 @@ describe('carousels reducer', () => {
 
   describe('CAROUSEL_AVATAR_REQUEST', () => {
     it('sets "isLoading" to "true"', () => {
-      const initialState = { isLoading: false, avatars: [] };
+      const initialState = { isLoading: false, avatars: [], error: false };
       const action = { type: CAROUSEL_AVATAR_REQUEST };
       expect(reducer(initialState, action).isLoading).toEqual(true);
     });
@@ -39,7 +39,7 @@ describe('carousels reducer', () => {
 
   describe('CAROUSEL_AVATAR_FAIL', () => {
     it('sets "isLoading" to "true"', () => {
-      const initialState = { isLoading: true, avatars: [] };
+      const initialState = { isLoading: true, avatars: [], error: false };
       const action = { type: CAROUSEL_AVATAR_FAIL };
       const result = reducer(initialState, action);
 
diff --git a/app/soapbox/reducers/__tests__/compose.test.ts b/app/soapbox/reducers/__tests__/compose.test.ts
index a1d40fe7c..bb6906c6d 100644
--- a/app/soapbox/reducers/__tests__/compose.test.ts
+++ b/app/soapbox/reducers/__tests__/compose.test.ts
@@ -200,7 +200,7 @@ describe('compose reducer', () => {
   });
 
   it('should handle COMPOSE_SENSITIVITY_CHANGE on Mark Sensitive click, don\'t toggle if spoiler active', () => {
-    const state = ReducerRecord({ spoiler: true, sensitive: true, idempotencyKey: null });
+    const state = ReducerRecord({ spoiler: true, sensitive: true, idempotencyKey: '' });
     const action = {
       type: actions.COMPOSE_SENSITIVITY_CHANGE,
     };
@@ -297,12 +297,12 @@ describe('compose reducer', () => {
   });
 
   it('should handle COMPOSE_SUBMIT_SUCCESS', () => {
-    const state = ReducerRecord({ default_privacy: null, privacy: 'public' });
+    const state = ReducerRecord({ default_privacy: 'public', privacy: 'private' });
     const action = {
       type: actions.COMPOSE_SUBMIT_SUCCESS,
     };
     expect(reducer(state, action).toJS()).toMatchObject({
-      privacy: null,
+      privacy: 'public',
     });
   });
 
diff --git a/app/soapbox/reducers/__tests__/custom_emojis.test.ts b/app/soapbox/reducers/__tests__/custom_emojis.test.ts
index 43fec78ec..e2991d5fb 100644
--- a/app/soapbox/reducers/__tests__/custom_emojis.test.ts
+++ b/app/soapbox/reducers/__tests__/custom_emojis.test.ts
@@ -4,6 +4,6 @@ import reducer from '../custom_emojis';
 
 describe('custom_emojis reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableList());
+    expect(reducer(undefined, {} as any)).toEqual(ImmutableList());
   });
 });
diff --git a/app/soapbox/reducers/__tests__/group_editor.test.ts b/app/soapbox/reducers/__tests__/group_editor.test.ts
index 73c9e1b6a..516b6df43 100644
--- a/app/soapbox/reducers/__tests__/group_editor.test.ts
+++ b/app/soapbox/reducers/__tests__/group_editor.test.ts
@@ -4,7 +4,7 @@ import reducer from '../group_editor';
 
 describe('group_editor reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+    expect(reducer(undefined, {} as any)).toEqual(ImmutableMap({
       groupId: null,
       isSubmitting: false,
       isChanged: false,
diff --git a/app/soapbox/reducers/__tests__/group_lists.test.ts b/app/soapbox/reducers/__tests__/group_lists.test.ts
index fa5c21eea..46527f682 100644
--- a/app/soapbox/reducers/__tests__/group_lists.test.ts
+++ b/app/soapbox/reducers/__tests__/group_lists.test.ts
@@ -4,7 +4,7 @@ import reducer from '../group_lists';
 
 describe('group_lists reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+    expect(reducer(undefined, {} as any)).toEqual(ImmutableMap({
       featured: ImmutableList(),
       member: ImmutableList(),
       admin: ImmutableList(),
diff --git a/app/soapbox/reducers/__tests__/group_relationships.test.ts b/app/soapbox/reducers/__tests__/group_relationships.test.ts
index 17cabf3c2..31e3e354f 100644
--- a/app/soapbox/reducers/__tests__/group_relationships.test.ts
+++ b/app/soapbox/reducers/__tests__/group_relationships.test.ts
@@ -4,6 +4,6 @@ import reducer from '../group_relationships';
 
 describe('group_relationships reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+    expect(reducer(undefined, {} as any)).toEqual(ImmutableMap());
   });
 });
diff --git a/app/soapbox/reducers/__tests__/groups.test.ts b/app/soapbox/reducers/__tests__/groups.test.ts
index 94a1a6ffe..05b88402f 100644
--- a/app/soapbox/reducers/__tests__/groups.test.ts
+++ b/app/soapbox/reducers/__tests__/groups.test.ts
@@ -4,6 +4,6 @@ import reducer from '../groups';
 
 describe('groups reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+    expect(reducer(undefined, {} as any)).toEqual(ImmutableMap());
   });
 });
diff --git a/app/soapbox/reducers/__tests__/index.test.ts b/app/soapbox/reducers/__tests__/index.test.ts
index 15572f337..e5674e91b 100644
--- a/app/soapbox/reducers/__tests__/index.test.ts
+++ b/app/soapbox/reducers/__tests__/index.test.ts
@@ -4,7 +4,7 @@ import reducer from '..';
 
 describe('root reducer', () => {
   it('should return the initial state', () => {
-    const result = reducer(undefined, {});
+    const result = reducer(undefined, {} as any);
     expect(ImmutableRecord.isRecord(result)).toBe(true);
     expect(result.accounts.get('')).toBe(undefined);
     expect(result.instance.version).toEqual('0.0.0');
diff --git a/app/soapbox/reducers/__tests__/meta.test.ts b/app/soapbox/reducers/__tests__/meta.test.ts
index d318b4a30..272116391 100644
--- a/app/soapbox/reducers/__tests__/meta.test.ts
+++ b/app/soapbox/reducers/__tests__/meta.test.ts
@@ -6,7 +6,7 @@ import reducer from '../meta';
 
 describe('meta reducer', () => {
   it('should return the initial state', () => {
-    const result = reducer(undefined, {});
+    const result = reducer(undefined, {} as any);
     expect(ImmutableRecord.isRecord(result)).toBe(true);
     expect(result.instance_fetch_failed).toBe(false);
     expect(result.swUpdating).toBe(false);
diff --git a/app/soapbox/reducers/__tests__/mutes.test.ts b/app/soapbox/reducers/__tests__/mutes.test.ts
index 411db10c6..66a866958 100644
--- a/app/soapbox/reducers/__tests__/mutes.test.ts
+++ b/app/soapbox/reducers/__tests__/mutes.test.ts
@@ -9,7 +9,7 @@ import reducer from '../mutes';
 
 describe('mutes reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {}).toJS()).toEqual({
+    expect(reducer(undefined, {} as any).toJS()).toEqual({
       new: {
         isSubmitting: false,
         accountId: null,
diff --git a/app/soapbox/reducers/__tests__/onboarding.test.ts b/app/soapbox/reducers/__tests__/onboarding.test.ts
index 95ecdf755..69b4b1b21 100644
--- a/app/soapbox/reducers/__tests__/onboarding.test.ts
+++ b/app/soapbox/reducers/__tests__/onboarding.test.ts
@@ -4,7 +4,7 @@ import reducer from '../onboarding';
 
 describe('onboarding reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual({
+    expect(reducer(undefined, {} as any)).toEqual({
       needsOnboarding: false,
     });
   });
@@ -12,7 +12,7 @@ describe('onboarding reducer', () => {
   describe('ONBOARDING_START', () => {
     it('sets "needsOnboarding" to "true"', () => {
       const initialState = { needsOnboarding: false };
-      const action = { type: ONBOARDING_START };
+      const action = { type: ONBOARDING_START } as any;
       expect(reducer(initialState, action).needsOnboarding).toEqual(true);
     });
   });
@@ -20,7 +20,7 @@ describe('onboarding reducer', () => {
   describe('ONBOARDING_END', () => {
     it('sets "needsOnboarding" to "false"', () => {
       const initialState = { needsOnboarding: true };
-      const action = { type: ONBOARDING_END };
+      const action = { type: ONBOARDING_END } as any;
       expect(reducer(initialState, action).needsOnboarding).toEqual(false);
     });
   });
diff --git a/app/soapbox/reducers/__tests__/rules.test.ts b/app/soapbox/reducers/__tests__/rules.test.ts
index 151516a83..25f8575ed 100644
--- a/app/soapbox/reducers/__tests__/rules.test.ts
+++ b/app/soapbox/reducers/__tests__/rules.test.ts
@@ -15,14 +15,14 @@ describe('rules reducer', () => {
 
   describe('RULES_FETCH_REQUEST', () => {
     it('sets "needsOnboarding" to "true"', () => {
-      const action = { type: RULES_FETCH_REQUEST };
+      const action = { type: RULES_FETCH_REQUEST } as any;
       expect(reducer(initialState, action).isLoading).toEqual(true);
     });
   });
 
   describe('ONBOARDING_END', () => {
     it('sets "needsOnboarding" to "false"', () => {
-      const action = { type: RULES_FETCH_SUCCESS, payload: [{ id: '123' }] };
+      const action = { type: RULES_FETCH_SUCCESS, payload: [{ id: '123' }] } as any;
       const result = reducer(initialState, action);
       expect(result.isLoading).toEqual(false);
       expect(result.items[0].id).toEqual('123');
diff --git a/app/soapbox/reducers/__tests__/settings.test.ts b/app/soapbox/reducers/__tests__/settings.test.ts
index b4574d55c..5b065fd4c 100644
--- a/app/soapbox/reducers/__tests__/settings.test.ts
+++ b/app/soapbox/reducers/__tests__/settings.test.ts
@@ -4,7 +4,7 @@ import reducer from '../settings';
 
 describe('settings reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+    expect(reducer(undefined, {} as any)).toEqual(ImmutableMap({
       saved: true,
     }));
   });
diff --git a/app/soapbox/reducers/__tests__/statuses.test.ts b/app/soapbox/reducers/__tests__/statuses.test.ts
index fb245062a..06d82c871 100644
--- a/app/soapbox/reducers/__tests__/statuses.test.ts
+++ b/app/soapbox/reducers/__tests__/statuses.test.ts
@@ -1,7 +1,6 @@
 import {
   Map as ImmutableMap,
   Record as ImmutableRecord,
-  fromJS,
 } from 'immutable';
 
 import { STATUS_IMPORT } from 'soapbox/actions/importer';
@@ -11,12 +10,13 @@ import {
   STATUS_DELETE_REQUEST,
   STATUS_DELETE_FAIL,
 } from 'soapbox/actions/statuses';
+import { normalizeStatus } from 'soapbox/normalizers';
 
-import reducer from '../statuses';
+import reducer, { ReducerStatus } from '../statuses';
 
 describe('statuses reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+    expect(reducer(undefined, {} as any)).toEqual(ImmutableMap());
   });
 
   describe('STATUS_IMPORT', () => {
@@ -35,7 +35,7 @@ describe('statuses reducer', () => {
       const expected = ['NEETzsche', 'alex', 'Lumeinshin', 'sneeden'];
 
       const result = reducer(undefined, action)
-        .getIn(['AFChectaqZjmOVkXZ2', 'mentions'])
+        .get('AFChectaqZjmOVkXZ2')?.mentions
         .map(mention => mention.get('username'))
         .toJS();
 
@@ -84,19 +84,18 @@ describe('statuses reducer', () => {
         remote_url: null,
       }];
 
-      expect(state.getIn(['017eeb0e-e5e7-98fe-6b2b-ad02349251fb', 'media_attachments']).toJS()).toMatchObject(expected);
+      expect(state.get('017eeb0e-e5e7-98fe-6b2b-ad02349251fb')?.media_attachments.toJS()).toMatchObject(expected);
     });
 
     it('fixes Pleroma attachments', () => {
       const status = require('soapbox/__fixtures__/pleroma-status-with-attachments.json');
       const action = { type: STATUS_IMPORT, status };
       const state = reducer(undefined, action);
-      const result = state.get('AGNkA21auFR5lnEAHw').media_attachments;
+      const result = state.get('AGNkA21auFR5lnEAHw')?.media_attachments;
 
-      expect(result.size).toBe(4);
-      expect(result.get(0).text_url).toBe(undefined);
-      expect(result.get(1).meta).toEqual(ImmutableMap());
-      expect(result.getIn([1, 'pleroma', 'mime_type'])).toBe('application/x-nes-rom');
+      expect(result?.size).toBe(4);
+      expect(result?.get(1)?.meta).toEqual(ImmutableMap());
+      expect(result?.getIn([1, 'pleroma', 'mime_type'])).toBe('application/x-nes-rom');
     });
 
     it('hides CWs', () => {
@@ -160,7 +159,9 @@ Promoting free speech, even for people and ideas you dislike`;
 
   describe('STATUS_CREATE_REQUEST', () => {
     it('increments the replies_count of its parent', () => {
-      const state = fromJS({ '123': { replies_count: 4 } });
+      const state = ImmutableMap({
+        '123': normalizeStatus({ replies_count: 4 }) as ReducerStatus,
+      });
 
       const action = {
         type: STATUS_CREATE_REQUEST,
@@ -174,7 +175,9 @@ Promoting free speech, even for people and ideas you dislike`;
 
   describe('STATUS_CREATE_FAIL', () => {
     it('decrements the replies_count of its parent', () => {
-      const state = fromJS({ '123': { replies_count: 5 } });
+      const state = ImmutableMap({
+        '123': normalizeStatus({ replies_count: 5 }) as ReducerStatus,
+      });
 
       const action = {
         type: STATUS_CREATE_FAIL,
@@ -188,7 +191,9 @@ Promoting free speech, even for people and ideas you dislike`;
 
   describe('STATUS_DELETE_REQUEST', () => {
     it('decrements the replies_count of its parent', () => {
-      const state = fromJS({ '123': { replies_count: 4 } });
+      const state = ImmutableMap({
+        '123': normalizeStatus({ replies_count: 4 }) as ReducerStatus,
+      });
 
       const action = {
         type: STATUS_DELETE_REQUEST,
@@ -200,7 +205,9 @@ Promoting free speech, even for people and ideas you dislike`;
     });
 
     it('gracefully does nothing if no parent', () => {
-      const state = fromJS({ '123': { replies_count: 4 } });
+      const state = ImmutableMap({
+        '123': normalizeStatus({ replies_count: 4 }) as ReducerStatus,
+      });
 
       const action = {
         type: STATUS_DELETE_REQUEST,
@@ -214,7 +221,9 @@ Promoting free speech, even for people and ideas you dislike`;
 
   describe('STATUS_DELETE_FAIL', () => {
     it('decrements the replies_count of its parent', () => {
-      const state = fromJS({ '123': { replies_count: 4 } });
+      const state = ImmutableMap({
+        '123': normalizeStatus({ replies_count: 4 }) as ReducerStatus,
+      });
 
       const action = {
         type: STATUS_DELETE_FAIL,
@@ -226,7 +235,9 @@ Promoting free speech, even for people and ideas you dislike`;
     });
 
     it('gracefully does nothing if no parent', () => {
-      const state = fromJS({ '123': { replies_count: 4 } });
+      const state = ImmutableMap({
+        '123': normalizeStatus({ replies_count: 4 }) as ReducerStatus,
+      });
 
       const action = {
         type: STATUS_DELETE_FAIL,
diff --git a/app/soapbox/reducers/__tests__/trends.test.ts b/app/soapbox/reducers/__tests__/trends.test.ts
index 644654038..25330d770 100644
--- a/app/soapbox/reducers/__tests__/trends.test.ts
+++ b/app/soapbox/reducers/__tests__/trends.test.ts
@@ -2,7 +2,7 @@ import reducer from '../trends';
 
 describe('trends reducer', () => {
   it('should return the initial state', () => {
-    expect(reducer(undefined, {}).toJS()).toEqual({
+    expect(reducer(undefined, {} as any).toJS()).toEqual({
       items: [],
       isLoading: false,
     });
diff --git a/app/soapbox/reducers/account_notes.ts b/app/soapbox/reducers/account_notes.ts
index f5d753ee3..0f30b8d60 100644
--- a/app/soapbox/reducers/account_notes.ts
+++ b/app/soapbox/reducers/account_notes.ts
@@ -10,13 +10,13 @@ import {
 
 import type { AnyAction } from 'redux';
 
-const EditRecord = ImmutableRecord({
+export const EditRecord = ImmutableRecord({
   isSubmitting: false,
-  account: null,
+  account: null as string | null,
   comment: '',
 });
 
-const ReducerRecord = ImmutableRecord({
+export const ReducerRecord = ImmutableRecord({
   edit: EditRecord(),
 });
 
diff --git a/app/soapbox/reducers/index.ts b/app/soapbox/reducers/index.ts
index 7f33dad1c..72b33f785 100644
--- a/app/soapbox/reducers/index.ts
+++ b/app/soapbox/reducers/index.ts
@@ -134,7 +134,6 @@ export const StateRecord = ImmutableRecord(
   }, {}),
 );
 
-// @ts-ignore: This type is fine but TS thinks it's wrong
 const appReducer = combineReducers(reducers, StateRecord);
 
 // Clear the state (mostly) when the user logs out
diff --git a/app/soapbox/reducers/user_lists.ts b/app/soapbox/reducers/user_lists.ts
index 99483a854..fc86cceb2 100644
--- a/app/soapbox/reducers/user_lists.ts
+++ b/app/soapbox/reducers/user_lists.ts
@@ -54,7 +54,7 @@ import {
 
 import type { APIEntity } from 'soapbox/types/entities';
 
-const ListRecord = ImmutableRecord({
+export const ListRecord = ImmutableRecord({
   next: null as string | null,
   items: ImmutableOrderedSet<string>(),
   isLoading: false,
@@ -72,7 +72,7 @@ const ReactionListRecord = ImmutableRecord({
   isLoading: false,
 });
 
-const ReducerRecord = ImmutableRecord({
+export const ReducerRecord = ImmutableRecord({
   followers: ImmutableMap<string, List>(),
   following: ImmutableMap<string, List>(),
   reblogged_by: ImmutableMap<string, List>(),
@@ -90,7 +90,7 @@ const ReducerRecord = ImmutableRecord({
 });
 
 type State = ReturnType<typeof ReducerRecord>;
-type List = ReturnType<typeof ListRecord>;
+export type List = ReturnType<typeof ListRecord>;
 type Reaction = ReturnType<typeof ReactionRecord>;
 type ReactionList = ReturnType<typeof ReactionListRecord>;
 type Items = ImmutableOrderedSet<string>;
diff --git a/app/soapbox/utils/__tests__/accounts.test.ts b/app/soapbox/utils/__tests__/accounts.test.ts
index cafedce35..878d278dd 100644
--- a/app/soapbox/utils/__tests__/accounts.test.ts
+++ b/app/soapbox/utils/__tests__/accounts.test.ts
@@ -4,11 +4,13 @@ import {
   getDomain,
 } from '../accounts';
 
+import type { ReducerAccount } from 'soapbox/reducers/accounts';
+
 describe('getDomain', () => {
   const account = AccountRecord({
     acct: 'alice',
     url: 'https://party.com/users/alice',
-  });
+  }) as ReducerAccount;
   it('returns the domain', () => {
     expect(getDomain(account)).toEqual('party.com');
   });
diff --git a/app/soapbox/utils/__tests__/numbers.test.tsx b/app/soapbox/utils/__tests__/numbers.test.tsx
index 63c45b26b..a0edf41fe 100644
--- a/app/soapbox/utils/__tests__/numbers.test.tsx
+++ b/app/soapbox/utils/__tests__/numbers.test.tsx
@@ -10,28 +10,28 @@ test('isIntegerId()', () => {
   expect(isIntegerId('-1764036199')).toBe(true);
   expect(isIntegerId('106801667066418367')).toBe(true);
   expect(isIntegerId('9v5bmRalQvjOy0ECcC')).toBe(false);
-  expect(isIntegerId(null)).toBe(false);
-  expect(isIntegerId(undefined)).toBe(false);
+  expect(isIntegerId(null as any)).toBe(false);
+  expect(isIntegerId(undefined as any)).toBe(false);
 });
 
 describe('shortNumberFormat', () => {
   test('handles non-numbers', () => {
-    render(<div data-testid='num'>{shortNumberFormat('not-number')}</div>, null, null);
+    render(<div data-testid='num'>{shortNumberFormat('not-number')}</div>, undefined, null);
     expect(screen.getByTestId('num')).toHaveTextContent('•');
   });
 
   test('formats numbers under 1,000', () => {
-    render(<div data-testid='num'>{shortNumberFormat(555)}</div>, null, null);
+    render(<div data-testid='num'>{shortNumberFormat(555)}</div>, undefined, null);
     expect(screen.getByTestId('num')).toHaveTextContent('555');
   });
 
   test('formats numbers under 1,000,000', () => {
-    render(<div data-testid='num'>{shortNumberFormat(5555)}</div>, null, null);
+    render(<div data-testid='num'>{shortNumberFormat(5555)}</div>, undefined, null);
     expect(screen.getByTestId('num')).toHaveTextContent('5.6K');
   });
 
   test('formats numbers over 1,000,000', () => {
-    render(<div data-testid='num'>{shortNumberFormat(5555555)}</div>, null, null);
+    render(<div data-testid='num'>{shortNumberFormat(5555555)}</div>, undefined, null);
     expect(screen.getByTestId('num')).toHaveTextContent('5.6M');
   });
 });
diff --git a/app/soapbox/utils/__tests__/status.test.ts b/app/soapbox/utils/__tests__/status.test.ts
index 4556382de..2bc803ee5 100644
--- a/app/soapbox/utils/__tests__/status.test.ts
+++ b/app/soapbox/utils/__tests__/status.test.ts
@@ -1,4 +1,3 @@
-import { fromJS } from 'immutable';
 
 import { normalizeStatus } from 'soapbox/normalizers/status';
 
@@ -7,9 +6,11 @@ import {
   defaultMediaVisibility,
 } from '../status';
 
+import type { ReducerStatus } from 'soapbox/reducers/statuses';
+
 describe('hasIntegerMediaIds()', () => {
   it('returns true for a Pleroma deleted status', () => {
-    const status = normalizeStatus(fromJS(require('soapbox/__fixtures__/pleroma-status-deleted.json')));
+    const status = normalizeStatus(require('soapbox/__fixtures__/pleroma-status-deleted.json')) as ReducerStatus;
     expect(hasIntegerMediaIds(status)).toBe(true);
   });
 });
@@ -20,17 +21,17 @@ describe('defaultMediaVisibility()', () => {
   });
 
   it('hides sensitive media by default', () => {
-    const status = normalizeStatus({ sensitive: true });
+    const status = normalizeStatus({ sensitive: true }) as ReducerStatus;
     expect(defaultMediaVisibility(status, 'default')).toBe(false);
   });
 
   it('hides media when displayMedia is hide_all', () => {
-    const status = normalizeStatus({});
+    const status = normalizeStatus({}) as ReducerStatus;
     expect(defaultMediaVisibility(status, 'hide_all')).toBe(false);
   });
 
   it('shows sensitive media when displayMedia is show_all', () => {
-    const status = normalizeStatus({ sensitive: true });
+    const status = normalizeStatus({ sensitive: true }) as ReducerStatus;
     expect(defaultMediaVisibility(status, 'show_all')).toBe(true);
   });
 });
diff --git a/app/soapbox/utils/__tests__/tailwind.test.ts b/app/soapbox/utils/__tests__/tailwind.test.ts
index 822408393..3c359ecc0 100644
--- a/app/soapbox/utils/__tests__/tailwind.test.ts
+++ b/app/soapbox/utils/__tests__/tailwind.test.ts
@@ -4,7 +4,7 @@ import { toTailwind, fromLegacyColors, expandPalette } from '../tailwind';
 
 describe('toTailwind()', () => {
   it('handles empty Soapbox config', () => {
-    const soapboxConfig = ImmutableMap();
+    const soapboxConfig = ImmutableMap<string, any>();
     const result = toTailwind(soapboxConfig);
     const expected = ImmutableMap({ colors: ImmutableMap() });
     expect(result).toEqual(expected);
diff --git a/app/soapbox/utils/__tests__/timelines.test.ts b/app/soapbox/utils/__tests__/timelines.test.ts
index df48bdae9..852a76ef6 100644
--- a/app/soapbox/utils/__tests__/timelines.test.ts
+++ b/app/soapbox/utils/__tests__/timelines.test.ts
@@ -4,70 +4,72 @@ import { normalizeStatus } from 'soapbox/normalizers/status';
 
 import { shouldFilter } from '../timelines';
 
+import type { ReducerStatus } from 'soapbox/reducers/statuses';
+
 describe('shouldFilter', () => {
   it('returns false under normal circumstances', () => {
     const columnSettings = fromJS({});
-    const status = normalizeStatus(fromJS({}));
+    const status = normalizeStatus({}) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(false);
   });
 
   it('reblog: returns true when `shows.reblog == false`', () => {
     const columnSettings = fromJS({ shows: { reblog: false } });
-    const status = normalizeStatus(fromJS({ reblog: {} }));
+    const status = normalizeStatus({ reblog: {} }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(true);
   });
 
   it('reblog: returns false when `shows.reblog == true`', () => {
     const columnSettings = fromJS({ shows: { reblog: true } });
-    const status = normalizeStatus(fromJS({ reblog: {} }));
+    const status = normalizeStatus({ reblog: {} }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(false);
   });
 
   it('reply: returns true when `shows.reply == false`', () => {
     const columnSettings = fromJS({ shows: { reply: false } });
-    const status = normalizeStatus(fromJS({ in_reply_to_id: '1234' }));
+    const status = normalizeStatus({ in_reply_to_id: '1234' }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(true);
   });
 
   it('reply: returns false when `shows.reply == true`', () => {
     const columnSettings = fromJS({ shows: { reply: true } });
-    const status = normalizeStatus(fromJS({ in_reply_to_id: '1234' }));
+    const status = normalizeStatus({ in_reply_to_id: '1234' }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(false);
   });
 
   it('direct: returns true when `shows.direct == false`', () => {
     const columnSettings = fromJS({ shows: { direct: false } });
-    const status = normalizeStatus(fromJS({ visibility: 'direct' }));
+    const status = normalizeStatus({ visibility: 'direct' }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(true);
   });
 
   it('direct: returns false when `shows.direct == true`', () => {
     const columnSettings = fromJS({ shows: { direct: true } });
-    const status = normalizeStatus(fromJS({ visibility: 'direct' }));
+    const status = normalizeStatus({ visibility: 'direct' }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(false);
   });
 
   it('direct: returns false for a public post when `shows.direct == false`', () => {
     const columnSettings = fromJS({ shows: { direct: false } });
-    const status = normalizeStatus(fromJS({ visibility: 'public' }));
+    const status = normalizeStatus({ visibility: 'public' }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(false);
   });
 
   it('multiple settings', () => {
     const columnSettings = fromJS({ shows: { reblog: false, reply: false, direct: false } });
-    const status = normalizeStatus(fromJS({ reblog: null, in_reply_to_id: null, visibility: 'direct' }));
+    const status = normalizeStatus({ reblog: null, in_reply_to_id: null, visibility: 'direct' }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(true);
   });
 
   it('multiple settings', () => {
     const columnSettings = fromJS({ shows: { reblog: false, reply: true, direct: false } });
-    const status = normalizeStatus(fromJS({ reblog: null, in_reply_to_id: '1234', visibility: 'public' }));
+    const status = normalizeStatus({ reblog: null, in_reply_to_id: '1234', visibility: 'public' }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(false);
   });
 
   it('multiple settings', () => {
     const columnSettings = fromJS({ shows: { reblog: true, reply: false, direct: true } });
-    const status = normalizeStatus(fromJS({ reblog: {}, in_reply_to_id: '1234', visibility: 'direct' }));
+    const status = normalizeStatus({ reblog: {}, in_reply_to_id: '1234', visibility: 'direct' }) as ReducerStatus;
     expect(shouldFilter(status, columnSettings)).toBe(true);
   });
 });
diff --git a/package.json b/package.json
index 7568e6eba..cb9ab4481 100644
--- a/package.json
+++ b/package.json
@@ -202,6 +202,7 @@
     "wicg-inert": "^3.1.1"
   },
   "devDependencies": {
+    "@jedmao/redux-mock-store": "^3.0.5",
     "@testing-library/jest-dom": "^5.16.4",
     "@testing-library/react-hooks": "^8.0.1",
     "@testing-library/user-event": "^14.0.3",
@@ -225,7 +226,6 @@
     "lint-staged": ">=10",
     "raf": "^3.4.1",
     "react-intl-translations-manager": "^5.0.3",
-    "redux-mock-store": "^1.5.4",
     "stylelint": "^13.7.2",
     "stylelint-config-standard": "^22.0.0",
     "stylelint-scss": "^3.18.0",
diff --git a/tsconfig.json b/tsconfig.json
index 8989bd57e..dba721d72 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -14,6 +14,5 @@
     "experimentalDecorators": true,
     "esModuleInterop": true,
     "typeRoots": [ "./types", "./node_modules/@types"]
-  },
-  "exclude": ["node_modules", "types", "**/*.test.*", "**/__mocks__/*", "**/__tests__/*"]
+  }
 }
diff --git a/types/redux-immutable/index.d.ts b/types/redux-immutable/index.d.ts
index 80d00209a..fbaecd198 100644
--- a/types/redux-immutable/index.d.ts
+++ b/types/redux-immutable/index.d.ts
@@ -13,5 +13,5 @@ declare module 'redux-immutable' {
   export function combineReducers<S, A extends Action, T>(reducers: ReducersMapObject<S, A>, getDefaultState?: () => Collection.Keyed<T, S>): Reducer<S, A>;
   export function combineReducers<S, A extends Action>(reducers: ReducersMapObject<S, A>, getDefaultState?: () => Collection.Indexed<S>): Reducer<S, A>;
   export function combineReducers<S>(reducers: ReducersMapObject<S, any>, getDefaultState?: () => Collection.Indexed<S>): Reducer<S>;
-  export function combineReducers<S, T extends object>(reducers: ReducersMapObject<S, any>, getDefaultState?: Record.Factory<T>): Reducer<S>;
+  export function combineReducers<S extends object, T extends object>(reducers: ReducersMapObject<S, any>, getDefaultState?: Record.Factory<T>): Reducer<ReturnType<Record.Factory<S>>>;
 }
diff --git a/yarn.lock b/yarn.lock
index 893a03639..8d2248152 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1603,6 +1603,11 @@
   resolved "https://registry.yarnpkg.com/@istanbuljs/schema/-/schema-0.1.3.tgz#e45e384e4b8ec16bce2fd903af78450f6bf7ec98"
   integrity sha512-ZXRY4jNvVgSVQ8DL3LTcakaAtXwTVUxE81hslsyD2AtoXW/wVob10HkOJ1X/pAlcI7D+2YoZKg5do8G/w6RYgA==
 
+"@jedmao/redux-mock-store@^3.0.5":
+  version "3.0.5"
+  resolved "https://registry.yarnpkg.com/@jedmao/redux-mock-store/-/redux-mock-store-3.0.5.tgz#015fa4fc96bfc02b61ca221d9ea0476b78c70c97"
+  integrity sha512-zNcVCd5/ekSMdQWk64CqTPM24D9Lo59st9KvS+fljGpQXV4SliB7Vo0NFQIgvQJWPYeeobdngnrGy0XbCaARNw==
+
 "@jest/console@^27.5.1":
   version "27.5.1"
   resolved "https://registry.yarnpkg.com/@jest/console/-/console-27.5.1.tgz#260fe7239602fe5130a94f1aa386eff54b014bba"
@@ -10028,13 +10033,6 @@ redux-immutable@^4.0.0:
   resolved "https://registry.yarnpkg.com/redux-immutable/-/redux-immutable-4.0.0.tgz#3a1a32df66366462b63691f0e1dc35e472bbc9f3"
   integrity sha1-Ohoy32Y2ZGK2NpHw4dw15HK7yfM=
 
-redux-mock-store@^1.5.4:
-  version "1.5.4"
-  resolved "https://registry.yarnpkg.com/redux-mock-store/-/redux-mock-store-1.5.4.tgz#90d02495fd918ddbaa96b83aef626287c9ab5872"
-  integrity sha512-xmcA0O/tjCLXhh9Fuiq6pMrJCwFRaouA8436zcikdIpYWWCjU76CRk+i2bHx8EeiSiMGnB85/lZdU3wIJVXHTA==
-  dependencies:
-    lodash.isplainobject "^4.0.6"
-
 redux-thunk@^2.2.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/redux-thunk/-/redux-thunk-2.3.0.tgz#51c2c19a185ed5187aaa9a2d08b666d0d6467622"