From 8b8053fb9153f94b572f252a7dc8b558191e291c Mon Sep 17 00:00:00 2001
From: Clairton Rodrigo Heinzen <clairton.rodrigo@gmail.com>
Date: Fri, 6 Jul 2018 17:01:05 -0300
Subject: [PATCH 1/4] Add custom args to personalization

---
 lib/bamboo/adapters/send_grid_adapter.ex | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/bamboo/adapters/send_grid_adapter.ex b/lib/bamboo/adapters/send_grid_adapter.ex
index fcf98797..4675a494 100644
--- a/lib/bamboo/adapters/send_grid_adapter.ex
+++ b/lib/bamboo/adapters/send_grid_adapter.ex
@@ -16,7 +16,7 @@ defmodule Bamboo.SendGridAdapter do
       config :my_app, MyApp.Mailer,
         adapter: Bamboo.SendGridAdapter,
         api_key: "my_api_key" # or {:system, "SENDGRID_API_KEY"}
-        
+
       # To enable sandbox mode (e.g. in development or staging environments),
       # in config/dev.exs or config/prod.exs etc
       config :my_app, MyApp.Mailer, sandbox: true
@@ -119,6 +119,7 @@ defmodule Bamboo.SendGridAdapter do
     |> put_to(email)
     |> put_cc(email)
     |> put_bcc(email)
+    |> put_custom_args(email)
     |> put_template_substitutions(email)
   end
 
@@ -194,6 +195,14 @@ defmodule Bamboo.SendGridAdapter do
 
   defp put_template_substitutions(body, _), do: body
 
+  defp put_custom_args(body, %Email{
+         private: %{custom_args: custom_args}
+       }) do
+    Map.put(body, :custom_args, custom_args)
+  end
+
+  defp put_custom_args(body, _), do: body
+
   defp put_categories(body, %Email{private: %{categories: categories}})
        when is_list(categories) and length(categories) <= 10 do
     body

From 8447b9d1410dda0e749e3614d520a6feb5f57ad1 Mon Sep 17 00:00:00 2001
From: Clairton Rodrigo Heinzen <clairton.rodrigo@gmail.com>
Date: Wed, 11 Jul 2018 11:28:00 -0300
Subject: [PATCH 2/4] if is empty not add custom_args

---
 lib/bamboo/adapters/send_grid_adapter.ex | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/bamboo/adapters/send_grid_adapter.ex b/lib/bamboo/adapters/send_grid_adapter.ex
index 4675a494..5a6ee081 100644
--- a/lib/bamboo/adapters/send_grid_adapter.ex
+++ b/lib/bamboo/adapters/send_grid_adapter.ex
@@ -195,6 +195,10 @@ defmodule Bamboo.SendGridAdapter do
 
   defp put_template_substitutions(body, _), do: body
 
+  defp put_custom_args(body, %Email{private: %{custom_args: custom_args}})
+       when length(custom_args) <= 0,
+       do: body
+
   defp put_custom_args(body, %Email{
          private: %{custom_args: custom_args}
        }) do

From ccc246092e7f2c748df5458a5516fda4b0e1fce5 Mon Sep 17 00:00:00 2001
From: Clairton Rodrigo Heinzen <clairton.rodrigo@gmail.com>
Date: Wed, 11 Jul 2018 16:27:50 -0300
Subject: [PATCH 3/4] if is nil not add custom_args

---
 lib/bamboo/adapters/send_grid_adapter.ex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/bamboo/adapters/send_grid_adapter.ex b/lib/bamboo/adapters/send_grid_adapter.ex
index 5a6ee081..d41dd3d6 100644
--- a/lib/bamboo/adapters/send_grid_adapter.ex
+++ b/lib/bamboo/adapters/send_grid_adapter.ex
@@ -196,7 +196,7 @@ defmodule Bamboo.SendGridAdapter do
   defp put_template_substitutions(body, _), do: body
 
   defp put_custom_args(body, %Email{private: %{custom_args: custom_args}})
-       when length(custom_args) <= 0,
+       when is_nil(custom_args) or length(custom_args) == 0,
        do: body
 
   defp put_custom_args(body, %Email{

From f2e4ddf177bbcf2c90d010c53c2fa9251fdf1b01 Mon Sep 17 00:00:00 2001
From: Clairton Rodrigo Heinzen <clairton.rodrigo@gmail.com>
Date: Tue, 7 Aug 2018 19:13:09 -0300
Subject: [PATCH 4/4] test custom_args

---
 .../adapters/send_grid_adapter_test.exs       | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/test/lib/bamboo/adapters/send_grid_adapter_test.exs b/test/lib/bamboo/adapters/send_grid_adapter_test.exs
index 4045711a..d332a165 100644
--- a/test/lib/bamboo/adapters/send_grid_adapter_test.exs
+++ b/test/lib/bamboo/adapters/send_grid_adapter_test.exs
@@ -134,6 +134,29 @@ defmodule Bamboo.SendGridAdapterTest do
            ]
   end
 
+  test "deliver/2 correctly custom args" do
+    email = new_email()
+
+    email
+    |> Email.put_private(:custom_args, %{post_code: "123"})
+    |> SendGridAdapter.deliver(@config)
+
+    assert_receive {:fake_sendgrid, %{params: params}}
+    personalization = List.first(params["personalizations"])
+    assert personalization["custom_args"] == %{"post_code" => "123"}
+  end
+
+  test "deliver/2 without custom args" do
+    email = new_email()
+
+    email
+    |> SendGridAdapter.deliver(@config)
+
+    assert_receive {:fake_sendgrid, %{params: params}}
+    personalization = List.first(params["personalizations"])
+    assert personalization["custom_args"] == nil
+  end
+
   test "deliver/2 correctly formats recipients" do
     email =
       new_email(