Dedupe poll options

lib/pleroma/web/common_api/utils.ex

@@ -145,6 +145,8 @@ def make_poll_data(%{poll: %{options: options, expires_in: expires_in}} = data)
       when is_list(options) do
     limits = Config.get([:instance, :poll_limits])
 
+    options = options |> Enum.uniq()
+
     with :ok <- validate_poll_expiration(expires_in, limits),
          :ok <- validate_poll_options_amount(options, limits),
          :ok <- validate_poll_options_length(options, limits) do
@@ -180,9 +182,14 @@ def make_poll_data(_data) do
   end
 
   defp validate_poll_options_amount(options, %{max_options: max_options}) do
-    if Enum.count(options) > max_options do
+    cond do
+      Enum.count(options) < 2 ->
+        {:error, "Poll must contain at least 2 options"}
+
+      Enum.count(options) > max_options ->
         {:error, "Poll can't contain more than #{max_options} options"}
-    else
+
+      true ->
         :ok
     end
   end

test/pleroma/web/mastodon_api/controllers/status_controller_test.exs

@@ -724,6 +724,32 @@ test "scheduled poll", %{conn: conn} do
       assert object.data["type"] == "Question"
       assert length(object.data["oneOf"]) == 3
     end
+
+    test "cannot have only one option", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/v1/statuses", %{
+          "status" => "desu~",
+          "poll" => %{"options" => ["mew"], "expires_in" => 1}
+        })
+
+      %{"error" => error} = json_response_and_validate_schema(conn, 422)
+      assert error == "Poll must contain at least 2 options"
+    end
+
+    test "cannot have only duplicated options", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/v1/statuses", %{
+          "status" => "desu~",
+          "poll" => %{"options" => ["mew", "mew"], "expires_in" => 1}
+        })
+
+      %{"error" => error} = json_response_and_validate_schema(conn, 422)
+      assert error == "Poll must contain at least 2 options"
+    end
   end
 
   test "get a status" do