From 350d36a86d283dbc3fbe258b456d17ef62865840 Mon Sep 17 00:00:00 2001
From: Gonzalo <456459+grzuy@users.noreply.github.com>
Date: Mon, 19 Aug 2024 13:12:13 -0300
Subject: [PATCH] feat: properly handles Plug.Cowboy handled throws and exits

---
 lib/tower/logger_handler.ex   |  4 +++
 test/plug/tower_plug_test.exs | 62 ++++++++++++++++++++++++++++++++++-
 test/support/test_plug.ex     | 12 +++++++
 3 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/lib/tower/logger_handler.ex b/lib/tower/logger_handler.ex
index 7fad7d9..bb74f22 100644
--- a/lib/tower/logger_handler.ex
+++ b/lib/tower/logger_handler.ex
@@ -40,6 +40,10 @@ defmodule Tower.LoggerHandler do
     Tower.handle_exit(exit_reason, stacktrace, log_event: log_event)
   end
 
+  def log(%{level: :error, meta: %{crash_reason: exit_reason}} = log_event, _config) do
+    Tower.handle_exit(exit_reason, [], log_event: log_event)
+  end
+
   def log(%{level: level, msg: {:string, reason_chardata}} = log_event, _config) do
     if should_handle?(level) do
       Tower.handle_message(level, IO.chardata_to_string(reason_chardata), log_event: log_event)
diff --git a/test/plug/tower_plug_test.exs b/test/plug/tower_plug_test.exs
index a08c2d7..69e5841 100644
--- a/test/plug/tower_plug_test.exs
+++ b/test/plug/tower_plug_test.exs
@@ -13,7 +13,7 @@ defmodule TowerPlugTest do
   end
 
   @tag capture_log: true
-  test "reports arithmetic error when a Plug.Conn IS present" do
+  test "reports arithmetic error during plug dispatch" do
     # An ephemeral port hopefully not being in the host running this code
     plug_port = 51111
     url = "http://127.0.0.1:#{plug_port}/arithmetic-error"
@@ -42,6 +42,66 @@ defmodule TowerPlugTest do
     assert Plug.Conn.request_url(plug_conn) == url
   end
 
+  @tag capture_log: true
+  test "reports uncaught throw during plug dispatch" do
+    # An ephemeral port hopefully not being in the host running this code
+    plug_port = 51111
+    url = "http://127.0.0.1:#{plug_port}/uncaught-throw"
+
+    start_link_supervised!({Plug.Cowboy, plug: Tower.TestPlug, scheme: :http, port: plug_port})
+
+    {:ok, _response} = :httpc.request(url)
+
+    assert_eventually(
+      [
+        %{
+          id: id,
+          datetime: datetime,
+          level: :error,
+          kind: :throw,
+          reason: "something",
+          stacktrace: stacktrace,
+          plug_conn: %Plug.Conn{} = plug_conn
+        }
+      ] = Tower.EphemeralReporter.events()
+    )
+
+    assert String.length(id) == 36
+    assert recent_datetime?(datetime)
+    assert is_list(stacktrace)
+    assert Plug.Conn.request_url(plug_conn) == url
+  end
+
+  @tag capture_log: true
+  test "reports abnormal exit during plug dispatch" do
+    # An ephemeral port hopefully not being in the host running this code
+    plug_port = 51111
+    url = "http://127.0.0.1:#{plug_port}/abnormal-exit"
+
+    start_link_supervised!({Plug.Cowboy, plug: Tower.TestPlug, scheme: :http, port: plug_port})
+
+    {:ok, _response} = :httpc.request(url)
+
+    assert_eventually(
+      [
+        %{
+          id: id,
+          datetime: datetime,
+          level: :error,
+          kind: :exit,
+          reason: :abnormal,
+          stacktrace: stacktrace,
+          plug_conn: %Plug.Conn{} = plug_conn
+        }
+      ] = Tower.EphemeralReporter.events()
+    )
+
+    assert String.length(id) == 36
+    assert recent_datetime?(datetime)
+    assert is_list(stacktrace)
+    assert Plug.Conn.request_url(plug_conn) == url
+  end
+
   test "reports message plug_conn manually" do
     Tower.handle_message(
       :info,
diff --git a/test/support/test_plug.ex b/test/support/test_plug.ex
index 694e949..40945b2 100644
--- a/test/support/test_plug.ex
+++ b/test/support/test_plug.ex
@@ -10,6 +10,18 @@ defmodule Tower.TestPlug do
     send_resp(conn, 200, "OK")
   end
 
+  get "/abnormal-exit" do
+    exit(:abnormal)
+
+    send_resp(conn, 200, "OK")
+  end
+
+  get "/uncaught-throw" do
+    throw("something")
+
+    send_resp(conn, 200, "OK")
+  end
+
   match _ do
     send_resp(conn, 404, "Not Found")
   end