Add refute_email_delivered_with helper, tests

lib/bamboo/test.ex

@@ -203,6 +203,41 @@ defmodule Bamboo.Test do
     end
   end
 
+  @doc """
+  Check that no email was sent with the given parameters
+
+  Similarly to `assert_email_delivered_with`, the assertion waits up to 100ms before
+  failing. Note that you need to send the email again if you want to make other
+  assertions after this, as this will receive the `{:delivered_email, email}` message.
+
+  ## Examples
+
+      Bamboo.Email.new_email(subject: "something") |> MyApp.Mailer.deliver
+      refute_email_delivered_with(subject: "something else") # Will pass
+
+      email = Bamboo.Email.new_email(subject: "something") |> MyApp.Mailer.deliver
+      refute_email_delivered_with(subject: ~r/some/) # Will fail
+  """
+  defmacro refute_email_delivered_with(email_params) do
+    quote bind_quoted: [email_params: email_params] do
+      import ExUnit.Assertions
+
+      received_email_params =
+        receive do
+          {:delivered_email, email} -> Map.from_struct(email)
+        after
+          100 -> []
+        end
+
+      if is_nil(received_email_params) do
+        refute false
+      else
+        refute Enum.any?(email_params, fn {k, v} -> do_match(received_email_params[k], v) end),
+               Bamboo.Test.flunk_attributes_match(email_params, received_email_params)
+      end
+    end
+  end
+
   @doc false
   def do_match(value1, value2 = %Regex{}) do
     Regex.match?(value2, value1)
@@ -263,6 +298,21 @@ defmodule Bamboo.Test do
     """
   end
 
+  @doc false
+  def flunk_attributes_match(params_given, params_received) do
+    """
+    The parameters given match.
+
+      Parameters given:
+
+        #{inspect(params_given)}
+
+      Email received:
+
+        #{inspect(params_received)}
+    """
+  end
+
   defp delivered_emails do
     {:messages, messages} = Process.info(self(), :messages)
 

test/lib/bamboo/adapters/test_adapter_test.exs

@@ -172,6 +172,47 @@ defmodule Bamboo.TestAdapterTest do
     end
   end
 
+  test "refute_email_delivered_with when email does not match" do
+    mail =
+      new_email(
+        to: [nil: "foo@bar.com"],
+        from: {nil, "baz@bar.com"},
+        subject: "coffee"
+      )
+
+    TestMailer.deliver_now(mail)
+    refute_email_delivered_with(subject: ~r/tea/)
+    refute_email_delivered_with(to: [nil: "something@else.com"])
+  end
+
+  test "refute_email_delivered_with when email matches" do
+    mail =
+      new_email(
+        to: [nil: "foo@bar.com"],
+        from: {nil, "foo@bar.com"},
+        subject: "vodka",
+        text_body: "I really like coffee"
+      )
+
+    TestMailer.deliver_now(mail)
+
+    assert_raise ExUnit.AssertionError, fn ->
+      refute_email_delivered_with(to: mail.to)
+    end
+
+    TestMailer.deliver_now(mail)
+
+    assert_raise ExUnit.AssertionError, fn ->
+      refute_email_delivered_with(subject: mail.subject)
+    end
+
+    TestMailer.deliver_now(mail)
+
+    assert_raise ExUnit.AssertionError, fn ->
+      refute_email_delivered_with(text_body: ~r/coffee/)
+    end
+  end
+
   test "assert_no_emails_delivered shows the delivered email" do
     sent_email = new_email(from: "foo@bar.com", to: ["foo@bar.com"])