introduce the before_interceptor

Author: tarzan

lib/bamboo/mailer.ex

@@ -203,8 +203,9 @@ defmodule Bamboo.Mailer do
 
   @doc false
   def deliver_now(adapter, email, config, opts) do
-    with %Bamboo.Email{blocked: false} = email <- apply_interceptors(email, config),
-         {:ok, email} <- validate_and_normalize(email, adapter) do
+    with %Bamboo.Email{blocked: false} = email <- apply_before_interceptors(email, config),
+         {:ok, email} <- validate_and_normalize(email, adapter),
+         %Bamboo.Email{blocked: false} = email <- apply_interceptors(email, config) do
       if empty_recipients?(email) do
         debug_unsent(email)
 
@@ -244,8 +245,9 @@ defmodule Bamboo.Mailer do
 
   @doc false
   def deliver_later(adapter, email, config) do
-    with %Bamboo.Email{blocked: false} = email <- apply_interceptors(email, config),
-         {:ok, email} <- validate_and_normalize(email, adapter) do
+    with %Bamboo.Email{blocked: false} = email <- apply_before_interceptors(email, config),
+         {:ok, email} <- validate_and_normalize(email, adapter),
+         %Bamboo.Email{blocked: false} = email <- apply_interceptors(email, config) do
       if empty_recipients?(email) do
         debug_unsent(email)
       else
@@ -355,6 +357,14 @@ defmodule Bamboo.Mailer do
     end)
   end
 
+  defp apply_before_interceptors(email, config) do
+    interceptors = config[:before_interceptors] || []
+
+    Enum.reduce(interceptors, email, fn interceptor, email ->
+      interceptor.call(email)
+    end)
+  end
+
   @doc """
   Wraps to, cc and bcc addresses in a list and normalizes email addresses.
 

test/lib/bamboo/mailer_test.exs

@@ -2,13 +2,17 @@ defmodule Bamboo.MailerTest do
   use ExUnit.Case
   alias Bamboo.Email
 
-  @mailer_config adapter: __MODULE__.DefaultAdapter, foo: :bar, interceptors: nil
+  @mailer_config adapter: __MODULE__.DefaultAdapter, foo: :bar, interceptors: nil, before_interceptors: nil
 
   setup context do
     config =
       Keyword.merge(
         @mailer_config,
-        [adapter: context[:adapter], interceptors: context[:interceptors]],
+        [
+          adapter: context[:adapter],
+          before_interceptors: context[:before_interceptors],
+          interceptors: context[:interceptors]
+        ],
         fn
           _key, default, nil -> default
           _key, _default, override -> override
@@ -459,6 +463,44 @@ defmodule Bamboo.MailerTest do
     end
   end
 
+  describe "before_interceptors" do
+    @tag before_interceptors: [Bamboo.InactiveUsersInterceptor]
+    test "deliver_now/1 must apply before_interceptors and block email if user is inactive" do
+      email = new_email(to: %Bamboo.User{email: "inactive@bar.com", active: false})
+      assert {:ok, %Bamboo.Email{blocked: true}} = Mailer.deliver_now(email)
+    end
+
+    @tag before_interceptors: [Bamboo.InactiveUsersInterceptor]
+    test "deliver_later/1 must apply before_interceptors and block email if user is inactive" do
+      email = new_email(to: %Bamboo.User{email: "inactive@bar.com", active: false})
+      assert {:ok, %Bamboo.Email{blocked: true}} = Mailer.deliver_later(email)
+    end
+
+    @tag before_interceptors: [Bamboo.InactiveUsersInterceptor]
+    test "deliver_now/1 must apply before_interceptors and block email if user has no email" do
+      email = new_email(to: %Bamboo.User{email: nil})
+      assert {:ok, %Bamboo.Email{blocked: true}} = Mailer.deliver_now(email)
+    end
+
+    @tag before_interceptors: [Bamboo.InactiveUsersInterceptor]
+    test "deliver_later/1 must apply before_interceptors and block email if user has no email" do
+      email = new_email(to: %Bamboo.User{email: nil})
+      assert {:ok, %Bamboo.Email{blocked: true}} = Mailer.deliver_later(email)
+    end
+
+    @tag before_interceptors: [Bamboo.InactiveUsersInterceptor]
+    test "deliver_now/1 does not block regular email on deliver now" do
+      email = new_email(to: %Bamboo.User{name: "John Doe", email: "active@bar.com", active: true})
+      assert {:ok, %Bamboo.Email{blocked: false, to: [{"John Doe", "active@bar.com"}]}} = Mailer.deliver_now(email)
+    end
+
+    @tag before_interceptors: [Bamboo.InactiveUsersInterceptor]
+    test "deliver_later/1 does not block regular email on deliver later" do
+      email = new_email(to: %Bamboo.User{name: "John Doe", email: "active@bar.com", active: true})
+      assert {:ok, %Bamboo.Email{blocked: false}} = Mailer.deliver_later(email)
+    end
+  end
+
   describe "interceptors" do
     @tag interceptors: [Bamboo.DenyListInterceptor, Bamboo.EnvInterceptor]
     test "deliver_now/1 must apply interceptors and send email if not intercepted" do

test/support/deny_list_interceptor.ex

@@ -3,19 +3,11 @@ defmodule Bamboo.DenyListInterceptor do
 
   @deny_list ["blocked@blocked.com"]
 
-  def call(%{to: recipients} = email) when is_list(recipients) do
-    if Enum.any?(recipients, &(&1 in @deny_list)) do
+  def call(email) do
+    if Enum.any?(email.to, &(elem(&1, 1) in @deny_list)) do
       Bamboo.Email.block(email)
     else
       email
     end
   end
-
-  def call(%{to: recipient} = email) when recipient in @deny_list do
-    Bamboo.Email.block(email)
-  end
-
-  def call(email) do
-    email
-  end
 end

test/support/inactive_users_interceptor.ex

@@ -0,0 +1,13 @@
+defmodule Bamboo.InactiveUsersInterceptor do
+  @behaviour Bamboo.Interceptor
+
+  def call(%{to: %{active: false}} = email) do
+    Bamboo.Email.block(email)
+  end
+
+  def call(%{to: %{email: nil}} = email) do
+    Bamboo.Email.block(email)
+  end
+
+  def call(email), do: email
+end

test/support/user.ex

@@ -0,0 +1,9 @@
+defmodule Bamboo.User do
+  defstruct [:name, :email, :active]
+end
+
+defimpl Bamboo.Formatter, for: Bamboo.User do
+  def format_email_address(%{name: name, email: email}, _opts) do
+    {name, email}
+  end
+end