From ea788b401ca0145993b92634d31bc9dccfbf373a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Ferreira?= <jmnsferreira@gmail.com>
Date: Thu, 28 Nov 2019 17:04:06 +0000
Subject: [PATCH] Adds `to_event` support for arbitrary structs
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Signed-off-by: João Ferreira <jmnsferreira@gmail.com>
---
 lib/timber/eventable.ex            | 17 +++++++++++++++++
 test/lib/timber/eventable_test.exs | 11 ++++++++++-
 test/support/test_struct.ex        |  4 ++++
 3 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 test/support/test_struct.ex

diff --git a/lib/timber/eventable.ex b/lib/timber/eventable.ex
index 736c29c..b928fa8 100644
--- a/lib/timber/eventable.ex
+++ b/lib/timber/eventable.ex
@@ -49,6 +49,8 @@ defimpl Timber.Eventable, for: Map do
 end
 
 defimpl Timber.Eventable, for: Any do
+  @upper_word_regex ~r/(^[A-Z]+$)|[A-Z][a-z0-9]*/
+
   def to_event(%{__exception__: true} = error) do
     message = Exception.message(error)
     module_name = Timber.Utils.Module.name(error.__struct__)
@@ -60,4 +62,19 @@ defimpl Timber.Eventable, for: Any do
       }
     }
   end
+
+  def to_event(%{__struct__: module} = struct) do
+    event_data = struct |> Map.from_struct()
+
+    event_namespace =
+      module
+      |> Module.split()
+      |> List.last()
+      |> String.split(@upper_word_regex, trim: true, include_captures: true)
+      |> Stream.map(&String.downcase/1)
+      |> Enum.join("_")
+      |> String.to_atom()
+
+    Map.new([{event_namespace, event_data}])
+  end
 end
diff --git a/test/lib/timber/eventable_test.exs b/test/lib/timber/eventable_test.exs
index 5994321..363188a 100644
--- a/test/lib/timber/eventable_test.exs
+++ b/test/lib/timber/eventable_test.exs
@@ -1,7 +1,7 @@
 defmodule Timber.EventableTest do
   use Timber.TestCase
 
-  alias Timber.Eventable
+  alias Timber.{Eventable, TestStruct}
 
   describe "Timber.Eventable.to_event/1" do
     test "map with a single root key" do
@@ -31,5 +31,14 @@ defmodule Timber.EventableTest do
                }
              }
     end
+
+    test "struct" do
+      struct = %TestStruct{}
+      event = Eventable.to_event(struct)
+
+      assert event == %{
+               test_struct: %{life: 42}
+             }
+    end
   end
 end
diff --git a/test/support/test_struct.ex b/test/support/test_struct.ex
new file mode 100644
index 0000000..252ef6f
--- /dev/null
+++ b/test/support/test_struct.ex
@@ -0,0 +1,4 @@
+defmodule Timber.TestStruct do
+  @moduledoc false
+  defstruct life: 42
+end