Use a callback strategy to short circuit the functions and print a nice error

lib/mix/tasks/pleroma/config.ex

@@ -14,13 +14,14 @@ defmodule Mix.Tasks.Pleroma.Config do
   @moduledoc File.read!("docs/administration/CLI_tasks/config.md")
 
   def run(["migrate_to_db"]) do
-    check_configdb()
+    check_configdb(fn ->
       start_pleroma()
       migrate_to_db()
+    end)
   end
 
   def run(["migrate_from_db" | options]) do
-    check_configdb()
+    check_configdb(fn ->
       start_pleroma()
 
       {opts, _} =
@@ -30,10 +31,11 @@ defmodule Mix.Tasks.Pleroma.Config do
         )
 
       migrate_from_db(opts)
+    end)
   end
 
   def run(["dump"]) do
-    check_configdb()
+    check_configdb(fn ->
       start_pleroma()
 
       header = config_header()
@@ -50,29 +52,32 @@ defmodule Mix.Tasks.Pleroma.Config do
       else
         shell_error("No settings in ConfigDB.")
       end
+    end)
   end
 
   def run(["dump", group, key]) do
-    check_configdb()
+    check_configdb(fn ->
       start_pleroma()
 
       group = maybe_atomize(group)
       key = maybe_atomize(key)
 
       dump_key(group, key)
+    end)
   end
 
   def run(["dump", group]) do
-    check_configdb()
+    check_configdb(fn ->
       start_pleroma()
 
       group = maybe_atomize(group)
 
       dump_group(group)
+    end)
   end
 
   def run(["groups"]) do
-    check_configdb()
+    check_configdb(fn ->
       start_pleroma()
 
       groups =
@@ -87,10 +92,11 @@ defmodule Mix.Tasks.Pleroma.Config do
         groups |> Enum.each(fn x -> shell_info("-  #{x}") end)
         shell_info("\r\n")
       end
+    end)
   end
 
   def run(["reset"]) do
-    check_configdb()
+    check_configdb(fn ->
       start_pleroma()
 
       shell_info("The following settings will be permanently removed:")
@@ -110,10 +116,11 @@ defmodule Mix.Tasks.Pleroma.Config do
       else
         shell_error("No changes made.")
       end
+    end)
   end
 
   def run(["delete", group]) do
-    check_configdb()
+    check_configdb(fn ->
       start_pleroma()
 
       group = maybe_atomize(group)
@@ -137,10 +144,11 @@ defmodule Mix.Tasks.Pleroma.Config do
       else
         shell_error("No settings in ConfigDB for #{inspect(group)}. Aborting.")
       end
+    end)
   end
 
   def run(["delete", group, key]) do
-    check_configdb()
+    check_configdb(fn ->
       start_pleroma()
 
       group = maybe_atomize(group)
@@ -157,6 +165,7 @@ defmodule Mix.Tasks.Pleroma.Config do
       else
         shell_error("No changes made.")
       end
+    end)
   end
 
   @spec migrate_to_db(Path.t() | nil) :: any()
@@ -282,7 +291,7 @@ defmodule Mix.Tasks.Pleroma.Config do
   end
 
   defp configdb_not_enabled do
-    raise(
+    shell_error(
       "ConfigDB not enabled. Please check the value of :configurable_from_database in your configuration."
     )
   end
@@ -336,9 +345,9 @@ defmodule Mix.Tasks.Pleroma.Config do
     end
   end
 
-  defp check_configdb() do
+  defp check_configdb(callback) do
     with true <- Pleroma.Config.get([:configurable_from_database]) do
-      :ok
+      callback.()
     else
       _ -> configdb_not_enabled()
     end

test/mix/tasks/pleroma/config_test.exs

@@ -22,8 +22,6 @@ defmodule Mix.Tasks.Pleroma.ConfigTest do
     :ok
   end
 
-  setup_all do: clear_config(:configurable_from_database, true)
-
   test "error if file with custom settings doesn't exist" do
     Mix.Tasks.Pleroma.Config.migrate_to_db("config/not_existance_config_file.exs")
 
@@ -36,6 +34,7 @@ defmodule Mix.Tasks.Pleroma.ConfigTest do
 
   describe "migrate_to_db/1" do
     setup do
+      clear_config(:configurable_from_database, true)
       initial = Application.get_env(:quack, :level)
       on_exit(fn -> Application.put_env(:quack, :level, initial) end)
     end
@@ -83,6 +82,7 @@ defmodule Mix.Tasks.Pleroma.ConfigTest do
 
   describe "with deletion temp file" do
     setup do
+      clear_config(:configurable_from_database, true)
       temp_file = "config/temp.exported_from_db.secret.exs"
 
       on_exit(fn ->
@@ -187,6 +187,9 @@ defmodule Mix.Tasks.Pleroma.ConfigTest do
     end
   end
 
+  describe "operations on database config" do
+    setup do: clear_config(:configurable_from_database, true)
+
     test "dumping a specific group" do
       insert(:config,
         group: :pleroma,
@@ -272,4 +275,26 @@ defmodule Mix.Tasks.Pleroma.ConfigTest do
       assert_receive {:mix_shell, :info,
                       ["config :pleroma, Pleroma.Captcha, [enabled: false]\r\n\r\n"]}
     end
+  end
+
+  describe "when configdb disabled" do
+    test "refuses to dump" do
+      clear_config(:configurable_from_database, false)
+
+      insert(:config,
+        group: :pleroma,
+        key: :instance,
+        value: [
+          name: "Pleroma Test"
+        ]
+      )
+
+      Mix.Tasks.Pleroma.Config.run(["dump"])
+
+      assert_receive {:mix_shell, :error,
+                      [
+                        "ConfigDB not enabled. Please check the value of :configurable_from_database in your configuration."
+                      ]}
+    end
+  end
 end