Extract easy commits out of cubq branch

.credo.exs

@@ -3,12 +3,14 @@
   configs: [
     %{
       name: "default",
+      strict: true,
       checks: [
         {Credo.Check.Readability.ImplTrue, tags: []},
         {Credo.Check.Readability.LargeNumbers, only_greater_than: 86400},
         {Credo.Check.Readability.ParenthesesOnZeroArityDefs, parens: true},
         {Credo.Check.Readability.Specs, tags: []},
-        {Credo.Check.Design.TagTODO, false}
+        {Credo.Check.Design.TagTODO, false},
+        {Credo.Check.Readability.StrictModuleLayout, tags: []}
       ]
     }
   ]

lib/jackalope.ex

@@ -1,13 +1,13 @@
 defmodule Jackalope do
-  use Supervisor
-
-  require Logger
-
   @moduledoc "README.md"
              |> File.read!()
              |> String.split("<!-- MDOC !-->")
              |> Enum.fetch!(1)
 
+  use Supervisor
+
+  require Logger
+
   @default_mqtt_server {
     Tortoise311.Transport.Tcp,
     host: "localhost", port: 1883

lib/jackalope/handler/logger.ex

@@ -6,10 +6,10 @@ defmodule Jackalope.Handler.Logger do
   specified in the option list passed to `Jackalope.start_link/1`.
   """
 
-  require Logger
-
   @behaviour Jackalope.Handler
 
+  require Logger
+
   @impl Jackalope.Handler
   def connection(status) do
     Logger.info("Connection status is: #{inspect(status)}")

lib/jackalope/session.ex

@@ -12,11 +12,11 @@ defmodule Jackalope.Session do
 
   use GenServer
 
-  require Logger
-
   alias __MODULE__, as: State
   alias Jackalope.{TortoiseClient, WorkList}
 
+  require Logger
+
   @publish_options [:qos, :retain]
   @work_list_options [:ttl]
   # One hour
@@ -202,7 +202,7 @@ defmodule Jackalope.Session do
         # drop the message, it is outside of the time to live
         if function_exported?(state.handler, :handle_error, 1) do
           reason = {:publish_error, cmd, :ttl_expired}
-          apply(state.handler, :handle_error, [reason])
+          state.handler.handle_error(reason)
         end
 
         {:noreply, state, {:continue, :consume_work_list}}

lib/jackalope/supervisor.ex

@@ -4,9 +4,11 @@ defmodule Jackalope.Supervisor do
   # Supervisor for the MQTT connection specific processes
 
   use Supervisor
-  require Logger
+
   alias Jackalope.TortoiseClient
 
+  require Logger
+
   @type init_arg ::
           {:app_handler, module()} | {:client_id, atom()} | {:connection_options, Keyword.t()}
 

lib/jackalope/tortoise_client.ex

@@ -6,9 +6,8 @@ defmodule Jackalope.TortoiseClient do
 
   use GenServer
 
-  require Logger
-
   alias Jackalope.Session
+  require Logger
 
   defmodule State do
     @moduledoc false
@@ -213,7 +212,7 @@ defmodule Jackalope.TortoiseClient do
       {:error, reason} ->
         if function_exported?(state.handler, :handle_error, 1) do
           reason = {:publish_error, {topic, payload, opts}, reason}
-          apply(state.handler, :handle_error, [reason])
+          state.handler.handle_error(reason)
         end
 
         {:error, reason}

lib/jackalope/tortoise_handler.ex

@@ -3,11 +3,11 @@ defmodule Jackalope.TortoiseHandler do
 
   @behaviour Tortoise311.Handler
 
-  require Logger
-
   alias __MODULE__, as: State
   alias Jackalope.Session
 
+  require Logger
+
   defstruct handler: nil, default_last_will: nil
 
   @impl Tortoise311.Handler
@@ -22,7 +22,7 @@ defmodule Jackalope.TortoiseHandler do
 
   @impl Tortoise311.Handler
   def last_will(%State{} = state) do
-    last_will = apply(state.handler, :last_will, []) || state.default_last_will
+    last_will = state.handler.last_will() || state.default_last_will
     packaged_last_will = package_last_will(last_will)
 
     {{:ok, packaged_last_will}, state}
@@ -34,7 +34,7 @@ defmodule Jackalope.TortoiseHandler do
     Session.report_connection_status(status)
 
     if function_exported?(state.handler, :connection, 1) do
-      _ignored = apply(state.handler, :connection, [status])
+      _ignored = state.handler.connection(status)
     end
 
     {:ok, state}
@@ -43,7 +43,7 @@ defmodule Jackalope.TortoiseHandler do
   @impl Tortoise311.Handler
   def subscription(status, topic_filter, %State{} = state) when status in [:up, :down] do
     if function_exported?(state.handler, :subscription, 2) do
-      _ignored = apply(state.handler, :subscription, [status, topic_filter])
+      _ignored = state.handler.subscription(status, topic_filter)
     end
 
     {:ok, state}
@@ -54,15 +54,15 @@ defmodule Jackalope.TortoiseHandler do
     case Jason.decode(payload_string) do
       {:ok, payload} ->
         # Dispatch to the handle message callback on the jackalope handler
-        apply(handler, :handle_message, [topic_levels, payload])
+        handler.handle_message(topic_levels, payload)
         {:ok, state}
 
       {:error, reason} ->
         # Dispatch to the handle error callback on the jackalope handler if
         # implemented
         if function_exported?(handler, :handle_error, 1) do
           reason = {:payload_decode_error, reason, {topic_levels, payload_string}}
-          apply(handler, :handle_error, [reason])
+          handler.handle_error(reason)
         end
 
         {:ok, state}

test/support/scripted_mqtt_server.ex

@@ -8,16 +8,16 @@ defmodule JackalopeTest.ScriptedMqttServer do
 
   use GenServer
 
+  alias Tortoise311.Package
+  alias __MODULE__, as: State
+
   defstruct transport: nil,
             server_socket: nil,
             script: [],
             client_pid: nil,
             client: nil,
             server_info: nil
 
-  alias Tortoise311.Package
-  alias __MODULE__, as: State
-
   # Client API
   @spec start_link() :: GenServer.on_start()
   def start_link() do