feat: automatically Tower.attach

lib/tower.ex

@@ -142,14 +142,6 @@ defmodule Tower do
       - [`TowerSlack`](https://hexdocs.pm/tower_slack) ([`tower_slack`](https://hex.pm/packages/tower_slack))
     - and properly set the `config :tower, :reporters, [...]` configuration key
 
-  ## Enabling automated exception handling
-
-      Tower.attach()
-
-  ## Disabling automated exception handling
-
-      Tower.detach()
-
   ## Manual handling
 
   If either, for whatever reason when using automated exception handling, an exception condition is
@@ -207,13 +199,6 @@ defmodule Tower do
 
       # in some config/*.exs
       config :tower, reporters: [MyApp.ErrorReporter]
-
-      # config/application.ex
-      Tower.attach()
-
-  `Tower.attach/0` will be responsible for registering the necessary handlers in your application
-  so that any uncaught exception, uncaught throw or abnormal process exit is handled by Tower and
-  passed along to the reporter.
   """
 
   defmodule ReportEventError do
@@ -278,11 +263,13 @@ defmodule Tower do
   Note that `Tower.attach/0` is not a precondition for `Tower` `handle_*` functions to work
   properly and inform reporters. They are independent.
   """
-  @spec attach() :: :ok
+  @spec attach() :: :ok | {:error, reason :: term()}
   def attach do
-    :ok = Tower.LoggerHandler.attach()
-    :ok = Tower.BanditExceptionHandler.attach()
-    :ok = Tower.ObanExceptionHandler.attach()
+    with :ok <- Tower.LoggerHandler.attach(),
+         :ok <- Tower.BanditExceptionHandler.attach(),
+         :ok <- Tower.ObanExceptionHandler.attach() do
+      :ok
+    end
   end
 
   @doc """
@@ -292,11 +279,13 @@ defmodule Tower do
   You can still manually call `Tower` `handle_*` functions and reporters will be informed about
   those events.
   """
-  @spec detach() :: :ok
+  @spec detach() :: :ok | {:error, reason :: term()}
   def detach do
-    :ok = Tower.LoggerHandler.detach()
-    :ok = Tower.BanditExceptionHandler.detach()
-    :ok = Tower.ObanExceptionHandler.detach()
+    with :ok <- Tower.LoggerHandler.detach(),
+         :ok <- Tower.BanditExceptionHandler.detach(),
+         :ok <- Tower.ObanExceptionHandler.detach() do
+      :ok
+    end
   end
 
   @doc """

lib/tower/application.ex

@@ -7,13 +7,22 @@ defmodule Tower.Application do
 
   @impl true
   def start(_type, _args) do
-    Supervisor.start_link(
-      [
-        Tower.EphemeralReporter,
-        {Task.Supervisor, name: Tower.TaskSupervisor}
-      ],
-      strategy: :one_for_one,
-      name: Tower.Supervisor
-    )
+    with {:ok, pid} <-
+           Supervisor.start_link(
+             [
+               Tower.EphemeralReporter,
+               {Task.Supervisor, name: Tower.TaskSupervisor}
+             ],
+             strategy: :one_for_one,
+             name: Tower.Supervisor
+           ),
+         :ok <- Tower.attach() do
+      {:ok, pid}
+    end
+  end
+
+  @impl true
+  def stop(_state) do
+    Tower.detach()
   end
 end

lib/tower/ephemeral_reporter.ex

@@ -13,8 +13,6 @@ defmodule Tower.EphemeralReporter do
       iex> Tower.EphemeralReporter.events()
       []
       iex> Application.put_env(:tower, :reporters, [Tower.EphemeralReporter])
-      iex> Tower.attach()
-      :ok
       iex> spawn(fn -> 1 / 0 end)
       iex> Process.sleep(200)
       :ok
@@ -23,8 +21,6 @@ defmodule Tower.EphemeralReporter do
       :error
       iex> event.reason
       %ArithmeticError{message: "bad argument in arithmetic expression"}
-      iex> Tower.detach()
-      :ok
   """
   @behaviour Tower.Reporter
 

test/tower/tower_oban_test.exs

@@ -20,10 +20,7 @@ defmodule TowerObanTest do
       Ecto.Migrator.up(TestApp.Repo, 0, TestApp.Repo.Migrations.AddOban)
     end)
 
-    Tower.attach()
-
     on_exit(fn ->
-      Tower.detach()
       Tower.EphemeralReporter.reset()
     end)
   end

test/tower/tower_plug_test.exs

@@ -6,10 +6,7 @@ defmodule TowerPlugTest do
   import ExUnit.CaptureLog, only: [capture_log: 1]
 
   setup do
-    Tower.attach()
-
     on_exit(fn ->
-      Tower.detach()
       Tower.EphemeralReporter.reset()
     end)
   end

test/tower_test.exs

@@ -7,10 +7,7 @@ defmodule TowerTest do
   import ExUnit.CaptureLog, only: [capture_log: 1]
 
   setup do
-    Tower.attach()
-
     on_exit(fn ->
-      Tower.detach()
       Tower.EphemeralReporter.reset()
     end)
   end