From 50fbd2402d6b4841f07fafa12ef7a8bdab0b560a Mon Sep 17 00:00:00 2001
From: David Levine <levine1726@protonmail.com>
Date: Tue, 27 Sep 2022 22:10:33 -0400
Subject: [PATCH 1/2] convert inject/1 to a macro

this ensures that Application.get_env is called only when inject is
enabled in the config. Otherwise, it does not get included in the compiled code.
---
 lib/inject.ex | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/lib/inject.ex b/lib/inject.ex
index 98fcf80..76b3fd3 100644
--- a/lib/inject.ex
+++ b/lib/inject.ex
@@ -8,21 +8,23 @@ defmodule Inject do
     :ok
   end
 
-  def i(mod) do
-    inject(mod)
-  end
-
-  def inject(mod) do
+  defmacro inject(mod) do
     if Application.get_env(:inject, :disabled) do
       mod
     else
-      Inject.Registry
-      |> Registry.lookup(mod)
-      |> Enum.reverse()
-      |> find_override() || mod
+      quote bind_quoted: [mod: mod] do
+        Inject.Registry
+        |> Registry.lookup(mod)
+        |> Enum.reverse()
+        |> find_override() || mod
+      end
     end
   end
 
+  def i(mod) do
+    inject(mod)
+  end
+
   defp find_override([]), do: nil
 
   defp find_override([{pid, {override, shared: shared}} | overrides]) do

From 557258039a85a5b6fdc4bc39c85b0c3da591b995 Mon Sep 17 00:00:00 2001
From: David Levine <levine1726@protonmail.com>
Date: Mon, 10 Oct 2022 09:54:49 -0400
Subject: [PATCH 2/2] update test to evaluate code with update env vars

---
 lib/inject.ex                      | 6 +++++-
 test/inject_configuration_test.exs | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/inject.ex b/lib/inject.ex
index 76b3fd3..e768430 100644
--- a/lib/inject.ex
+++ b/lib/inject.ex
@@ -8,7 +8,7 @@ defmodule Inject do
     :ok
   end
 
-  defmacro inject(mod) do
+  defmacro inject_module(mod) do
     if Application.get_env(:inject, :disabled) do
       mod
     else
@@ -25,6 +25,10 @@ defmodule Inject do
     inject(mod)
   end
 
+  def inject(mod) do
+    inject_module(mod)
+  end
+
   defp find_override([]), do: nil
 
   defp find_override([{pid, {override, shared: shared}} | overrides]) do
diff --git a/test/inject_configuration_test.exs b/test/inject_configuration_test.exs
index 5da06bd..503e41b 100644
--- a/test/inject_configuration_test.exs
+++ b/test/inject_configuration_test.exs
@@ -19,7 +19,7 @@ defmodule InjectConfigurationTest do
     test "it does not lookup modules in the registry" do
       register(ExampleModule, StubModule)
       Application.put_env(:inject, :disabled, true)
-      assert "unstubbed" = i(ExampleModule).hello()
+      assert {"unstubbed", []} = Code.eval_quoted(quote(do: inject_module(ExampleModule).hello()))
       Application.put_env(:inject, :disabled, false)
     end
   end