From 68106b8386032f116afc84a94d9c3e0e99063351 Mon Sep 17 00:00:00 2001
From: Gonzalo <456459+grzuy@users.noreply.github.com>
Date: Mon, 12 Aug 2024 14:44:38 -0300
Subject: [PATCH] feat: Tower.Event datetime insead of :logger.timestamp

---
 lib/tower/ephemeral_reporter.ex | 27 +++++++-----
 lib/tower/event.ex              | 26 ++++++++----
 test/tower_test.exs             | 73 ++++++++++++++++++---------------
 3 files changed, 77 insertions(+), 49 deletions(-)

diff --git a/lib/tower/ephemeral_reporter.ex b/lib/tower/ephemeral_reporter.ex
index 5858c1a..508920b 100644
--- a/lib/tower/ephemeral_reporter.ex
+++ b/lib/tower/ephemeral_reporter.ex
@@ -20,39 +20,46 @@ defmodule Tower.EphemeralReporter do
 
   defp do_report_event(%Event{
          id: id,
-         time: time,
+         datetime: datetime,
          kind: :error,
          reason: exception,
          stacktrace: stacktrace,
          metadata: metadata
        }) do
-    add_error(id, time, exception.__struct__, Exception.message(exception), stacktrace, metadata)
+    add_error(
+      id,
+      datetime,
+      exception.__struct__,
+      Exception.message(exception),
+      stacktrace,
+      metadata
+    )
   end
 
   defp do_report_event(%Event{
          id: id,
-         time: time,
+         datetime: datetime,
          kind: :exit,
          reason: reason,
          stacktrace: stacktrace,
          metadata: metadata
        }) do
-    add_error(id, time, :exit, reason, stacktrace, metadata)
+    add_error(id, datetime, :exit, reason, stacktrace, metadata)
   end
 
   defp do_report_event(%Event{
          id: id,
-         time: time,
+         datetime: datetime,
          kind: :throw,
          reason: reason,
          stacktrace: stacktrace
        }) do
-    add_error(id, time, :throw, reason, stacktrace)
+    add_error(id, datetime, :throw, reason, stacktrace)
   end
 
   defp do_report_event(%Event{
          id: id,
-         time: time,
+         datetime: datetime,
          kind: :message,
          level: level,
          reason: message,
@@ -60,7 +67,7 @@ defmodule Tower.EphemeralReporter do
        }) do
     add(%{
       id: id,
-      time: time,
+      datetime: datetime,
       level: level,
       kind: nil,
       reason: message,
@@ -73,10 +80,10 @@ defmodule Tower.EphemeralReporter do
     Agent.get(__MODULE__, & &1)
   end
 
-  defp add_error(id, time, kind, reason, stacktrace, metadata \\ %{}) do
+  defp add_error(id, datetime, kind, reason, stacktrace, metadata \\ %{}) do
     add(%{
       id: id,
-      time: time,
+      datetime: datetime,
       level: :error,
       kind: kind,
       reason: reason,
diff --git a/lib/tower/event.ex b/lib/tower/event.ex
index 292caa9..98978f0 100644
--- a/lib/tower/event.ex
+++ b/lib/tower/event.ex
@@ -1,5 +1,5 @@
 defmodule Tower.Event do
-  defstruct [:id, :time, :level, :kind, :reason, :stacktrace, :log_event, :metadata]
+  defstruct [:id, :datetime, :level, :kind, :reason, :stacktrace, :log_event, :metadata]
 
   @type error_kind :: :error | :exit | :throw
   @type non_error_kind :: :message
@@ -7,7 +7,7 @@ defmodule Tower.Event do
 
   @type t :: %__MODULE__{
           id: Uniq.UUID.t(),
-          time: :logger.timestamp(),
+          datetime: DateTime.t(),
           level: :logger.level(),
           kind: error_kind() | non_error_kind(),
           reason: reason(),
@@ -16,6 +16,8 @@ defmodule Tower.Event do
           metadata: map()
         }
 
+  @logger_time_unit :microsecond
+
   @spec from_caught(Exception.kind(), reason(), Exception.stacktrace()) :: t()
   @spec from_caught(Exception.kind(), reason(), Exception.stacktrace(), Keyword.t()) :: t()
   def from_caught(kind, reason, stacktrace, options \\ [])
@@ -44,7 +46,7 @@ defmodule Tower.Event do
 
     %__MODULE__{
       id: new_id(),
-      time: log_event[:meta][:time] || now(),
+      datetime: event_datetime(log_event),
       level: :error,
       kind: :error,
       reason: exception,
@@ -61,7 +63,7 @@ defmodule Tower.Event do
 
     %__MODULE__{
       id: new_id(),
-      time: log_event[:meta][:time] || now(),
+      datetime: event_datetime(log_event),
       level: :error,
       kind: :exit,
       reason: reason,
@@ -78,7 +80,7 @@ defmodule Tower.Event do
 
     %__MODULE__{
       id: new_id(),
-      time: log_event[:meta][:time] || now(),
+      datetime: event_datetime(log_event),
       level: :error,
       kind: :throw,
       reason: reason,
@@ -95,7 +97,7 @@ defmodule Tower.Event do
 
     %__MODULE__{
       id: new_id(),
-      time: log_event[:meta][:time] || now(),
+      datetime: event_datetime(log_event),
       level: level,
       kind: :message,
       reason: message,
@@ -104,7 +106,17 @@ defmodule Tower.Event do
     }
   end
 
-  defp now do
+  defp event_datetime(log_event) do
+    log_event
+    |> event_timestamp()
+    |> DateTime.from_unix!(@logger_time_unit)
+  end
+
+  defp event_timestamp(%{meta: %{time: log_event_time}}) do
+    log_event_time
+  end
+
+  defp event_timestamp(_) do
     :logger.timestamp()
   end
 
diff --git a/test/tower_test.exs b/test/tower_test.exs
index 44268f9..820ef71 100644
--- a/test/tower_test.exs
+++ b/test/tower_test.exs
@@ -27,7 +27,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: ArithmeticError,
           reason: "bad argument in arithmetic expression",
@@ -37,7 +37,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -51,7 +51,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: RuntimeError,
           reason: "error inside process",
@@ -61,7 +61,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -75,7 +75,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: :throw,
           reason: "error",
@@ -85,7 +85,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -99,7 +99,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: :throw,
           reason: [something: "here"],
@@ -109,7 +109,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -131,7 +131,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: :exit,
           reason: :abnormal,
@@ -141,7 +141,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -155,7 +155,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: :exit,
           reason: :kill,
@@ -165,7 +165,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -192,7 +192,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: nil,
           reason: "Something went wrong here",
@@ -202,7 +202,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
   end
 
   @tag capture_log: true
@@ -225,7 +225,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: nil,
           reason:
@@ -236,7 +236,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
   end
 
   @tag capture_log: true
@@ -250,7 +250,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :critical,
           kind: nil,
           reason: [something: :reported, this: :critical],
@@ -260,7 +260,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
   end
 
   test "reports message manually" do
@@ -270,7 +270,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :info,
           kind: nil,
           reason: "Something interesting",
@@ -283,7 +283,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
   end
 
   test "reports Exception manually" do
@@ -299,7 +299,7 @@ defmodule TowerTest do
     assert_eventually(
       [
         %{
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: ArithmeticError,
           reason: "bad argument in arithmetic expression",
@@ -308,7 +308,7 @@ defmodule TowerTest do
       ] = reported_events()
     )
 
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -326,7 +326,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: ArithmeticError,
           reason: "bad argument in arithmetic expression",
@@ -336,7 +336,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -354,7 +354,7 @@ defmodule TowerTest do
     assert_eventually(
       [
         %{
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: :throw,
           reason: "error",
@@ -363,7 +363,7 @@ defmodule TowerTest do
       ] = reported_events()
     )
 
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -382,7 +382,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: :throw,
           reason: "error",
@@ -392,7 +392,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -410,7 +410,7 @@ defmodule TowerTest do
     assert_eventually(
       [
         %{
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: :exit,
           reason: :abnormal,
@@ -419,7 +419,7 @@ defmodule TowerTest do
       ] = reported_events()
     )
 
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -438,7 +438,7 @@ defmodule TowerTest do
       [
         %{
           id: id,
-          time: time,
+          datetime: datetime,
           level: :error,
           kind: :exit,
           reason: :abnormal,
@@ -448,7 +448,7 @@ defmodule TowerTest do
     )
 
     assert String.length(id) == 36
-    assert_in_delta(time, :logger.timestamp(), 100_000)
+    assert recent_datetime?(datetime)
     assert is_list(stacktrace)
   end
 
@@ -480,4 +480,13 @@ defmodule TowerTest do
       end
     end)
   end
+
+  defp recent_datetime?(datetime) do
+    diff =
+      :logger.timestamp()
+      |> DateTime.from_unix!(:microsecond)
+      |> DateTime.diff(datetime, :microsecond)
+
+    diff >= 0 && diff < 100_000
+  end
 end