Refactor copypasta to a private function in instance.ex

lib/mix/tasks/pleroma/instance.ex

@@ -59,49 +59,37 @@ def run(["new" | rest]) do
 
     unless not proceed? do
       domain =
-        Keyword.get(options, :domain) ||
-          Mix.shell().prompt("What domain will your instance use? (e.g. pleroma.soykaf.com)")
-          |> String.trim()
+        get_option(
+          options,
+          :domain,
+          "What domain will your instance use? (e.g pleroma.soykaf.com)"
+        )
 
       name =
-        Keyword.get(options, :name) ||
-          Mix.shell().prompt("What is the name of your instance? (e.g. Pleroma/Soykaf)")
-          |> String.trim()
+        get_option(options, :name, "What is the name of your instance? (e.g. Pleroma/Soykaf)")
 
-      email =
-        Keyword.get(options, :admin_email) ||
-          Mix.shell().prompt("What is your admin email address?")
-          |> String.trim()
+      email = get_option(options, :admin_email, "What is your admin email address?")
 
-      dbhost =
-        Keyword.get(options, :dbhost) ||
-          case Mix.shell().prompt("What is the hostname of your database? [localhost]") do
-            "\n" -> "localhost"
-            dbhost -> dbhost |> String.trim()
-          end
+      dbhost = get_option(options, :dbhost, "What is the hostname of your database?", "localhost")
 
-      dbname =
-        Keyword.get(options, :dbname) ||
-          case Mix.shell().prompt("What is the name of your database? [pleroma_dev]") do
-            "\n" -> "pleroma_dev"
-            dbname -> dbname |> String.trim()
-          end
+      dbname = get_option(options, :dbname, "What is the name of your database?", "pleroma_dev")
 
       dbuser =
-        Keyword.get(options, :dbuser) ||
-          case Mix.shell().prompt("What is the user used to connect to your database? [pleroma]") do
-            "\n" -> "pleroma"
-            dbuser -> dbuser |> String.trim()
-          end
+        get_option(
+          options,
+          :dbuser,
+          "What is the user used to connect to your database?",
+          "pleroma"
+        )
 
       dbpass =
-        Keyword.get(options, :dbpass) ||
-          case Mix.shell().prompt(
-                 "What is the password used to connect to your database? [autogenerated]"
-               ) do
-            "\n" -> :crypto.strong_rand_bytes(64) |> Base.encode64() |> binary_part(0, 64)
-            dbpass -> dbpass |> String.trim()
-          end
+        get_option(
+          options,
+          :dbpass,
+          "What is the password used to connect to your database?",
+          :crypto.strong_rand_bytes(64) |> Base.encode64() |> binary_part(0, 64),
+          "autogenerated"
+        )
 
       secret = :crypto.strong_rand_bytes(64) |> Base.encode64() |> binary_part(0, 64)
 
@@ -160,4 +148,18 @@ def run(["new" | rest]) do
   defp escape_sh_path(path) do
     ~S(') <> String.replace(path, ~S('), ~S(\')) <> ~S(')
   end
+
+  defp get_option(options, opt, prompt, def \\ nil, defname \\ nil) do
+    Keyword.get(options, opt) ||
+      case Mix.shell().prompt("#{prompt} [#{defname || def}]") do
+        "\n" ->
+          case def do
+            nil -> get_option(options, opt, prompt, def)
+            def -> def
+          end
+
+        opt ->
+          opt |> String.trim()
+      end
+  end
 end