From 040359a2069b8f193153294b802388e7ad89c463 Mon Sep 17 00:00:00 2001
From: Marc Delagrammatikas <marc@mechanical-orchard.com>
Date: Sun, 23 Apr 2023 15:57:25 -0700
Subject: [PATCH] overwrites the default result value

---
 lib/open_telemetry_decorator.ex        |  5 ++++-
 mix.exs                                |  2 +-
 test/open_telemetry_decorator_test.exs | 15 +++++++++++++++
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/lib/open_telemetry_decorator.ex b/lib/open_telemetry_decorator.ex
index 01bec22..93fd3b8 100644
--- a/lib/open_telemetry_decorator.ex
+++ b/lib/open_telemetry_decorator.ex
@@ -44,7 +44,10 @@ defmodule OpenTelemetryDecorator do
       require OpenTelemetry.Tracer, as: Tracer
 
       OpenTelemetry.Tracer.with_span unquote(span_name) do
-        input_params = Attributes.get(Kernel.binding(), unquote(include))
+        input_params =
+          Kernel.binding()
+          |> Attributes.get(unquote(include))
+          |> Keyword.delete(:result)
 
         try do
           result = unquote(body)
diff --git a/mix.exs b/mix.exs
index bf69033..f9d2de7 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,7 +1,7 @@
 defmodule OpenTelemetryDecorator.MixProject do
   use Mix.Project
 
-  @version "1.3.0"
+  @version "1.3.1"
   @github_page "https://github.com/marcdel/open_telemetry_decorator"
 
   def project do
diff --git a/test/open_telemetry_decorator_test.exs b/test/open_telemetry_decorator_test.exs
index 0d8855c..c63b46b 100644
--- a/test/open_telemetry_decorator_test.exs
+++ b/test/open_telemetry_decorator_test.exs
@@ -149,6 +149,21 @@ defmodule OpenTelemetryDecoratorTest do
       assert Map.get(get_span_attributes(attrs), :x) == 1
     end
 
+    test "overwrites the default result value" do
+      defmodule ExampleResult do
+        use OpenTelemetryDecorator
+
+        @decorate trace("ExampleResult.add", include: [:a, :b, :result])
+        def add(a, b) do
+          a + b
+        end
+      end
+
+      ExampleResult.add(5, 5)
+      assert_receive {:span, span(name: "ExampleResult.add", attributes: attrs)}
+      assert Map.get(get_span_attributes(attrs), :result) == 10
+    end
+
     test "does not include anything unless specified" do
       Example.no_include(include_me: "nope")
       assert_receive {:span, span(name: "Example.no_include", attributes: attrs)}