1 files changed, 39 insertions, 0 deletions
diff --git a/actionmailer/test/asset_host_test.rb b/actionmailer/test/asset_host_test.rb
new file mode 100644
index 0000000000..9cd8cae88c
--- /dev/null
+++ b/actionmailer/test/asset_host_test.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+require "abstract_unit"
+require "action_controller"
+
+class AssetHostMailer < ActionMailer::Base
+  def email_with_asset
+    mail to: "test@localhost",
+      subject: "testing email containing asset path while asset_host is set",
+      from: "tester@example.com"
+  end
+end
+
+class AssetHostTest < ActionMailer::TestCase
+  def setup
+    AssetHostMailer.configure do |c|
+      c.asset_host = "http://www.example.com"
+    end
+  end
+
+  def teardown
+    restore_delivery_method
+  end
+
+  def test_asset_host_as_string
+    mail = AssetHostMailer.email_with_asset
+    assert_dom_equal '<img src="http://www.example.com/images/somelogo.png" />', mail.body.to_s.strip
+  end
+
+  def test_asset_host_as_one_argument_proc
+    AssetHostMailer.config.asset_host = Proc.new { |source|
+      if source.starts_with?("/images")
+        "http://images.example.com"
+      end
+    }
+    mail = AssetHostMailer.email_with_asset
+    assert_dom_equal '<img src="http://images.example.com/images/somelogo.png" />', mail.body.to_s.strip
+  end
+end