Empty recipients

lib/bamboo/adapters/mandrill_adapter.ex

@@ -11,24 +11,22 @@ defmodule Bamboo.MandrillAdapter do
 
       Here is the response:
 
-      #{inspect response}
+      #{inspect response, limit: :infinity}
 
 
-      Here are the params we sent:
+      Here are the params that were sent:
 
-      #{inspect Poison.decode!(params)}
+      #{inspect Poison.decode!(params), limit: :infinity}
       """
       %ApiError{message: message}
     end
   end
 
   def deliver(email, config) do
-    api_key = get_key(config)
-    params = email |> convert_to_mandrill_params(api_key) |> Poison.encode!
-    case request!(@send_message_path, params) do
-      %{status_code: status} = response when status > 299 ->
-        raise(ApiError, %{params: params, response: response})
-      response -> response
+    if email.to == [] and email.cc == [] and email.bcc == [] do
+      {:no_recipients, email}
+    else
+      send_email(email, config)
     end
   end
 
@@ -38,6 +36,16 @@ defmodule Bamboo.MandrillAdapter do
     end)
   end
 
+  defp send_email(email, config) do
+    api_key = get_key(config)
+    params = email |> convert_to_mandrill_params(api_key) |> Poison.encode!
+    case request!(@send_message_path, params) do
+      %{status_code: status} = response when status > 299 ->
+        raise(ApiError, %{params: params, response: response})
+      response -> response
+    end
+  end
+
   defp get_key(config) do
     case Keyword.get(config, :api_key) do
       nil -> raise_api_key_error(config)

lib/bamboo/email.ex

@@ -1,8 +1,8 @@
 defmodule Bamboo.Email do
   defstruct from: nil,
-      to: nil,
-      cc: nil,
-      bcc: nil,
+      to: [],
+      cc: [],
+      bcc: [],
       subject: nil,
       html_body: nil,
       text_body: nil,

lib/bamboo/mailer.ex

@@ -3,6 +3,26 @@ defmodule Bamboo.Mailer do
 
   alias Bamboo.Formatter
 
+  defmodule NoRecipientError do
+    defexception [:message]
+
+    def exception(email) do
+      message = """
+      There was a recipient accidentally set to nil. If you meant to set the
+      to, cc or bcc fields to send to no one, set it to an empty list [] instead.
+
+      Recipients:
+
+      To - #{inspect email.to}
+      Cc - #{inspect email.cc}
+      Bcc - #{inspect email.bcc}
+
+      Full email - #{inspect email, limit: :infinity}
+      """
+      %NoRecipientError{message: message}
+    end
+  end
+
   defmacro __using__(opts) do
     quote bind_quoted: [opts: opts] do
       %{adapter: adapter, config: config} = Bamboo.Mailer.parse_opts(__MODULE__, opts)
@@ -21,18 +41,23 @@ defmodule Bamboo.Mailer do
   end
 
   def deliver(adapter, email, config) do
-    email = email |> Bamboo.Mailer.normalize_addresses
-
-    debug(email)
-    adapter.deliver(email, config)
+    email |> validate_and_normalize |> adapter.deliver(config)
   end
 
   def deliver_async(adapter, email, config) do
-    email = email |> Bamboo.Mailer.normalize_addresses
+    email |> validate_and_normalize |> adapter.deliver_async(config)
+  end
 
+  defp validate_and_normalize(email) do
+    email = email |> validate_recipients |> normalize_addresses
     debug(email)
-    adapter.deliver_async(email, config)
+    email
+  end
+
+  defp validate_recipients(%{to: to, cc: cc, bcc: bcc} = email) when is_nil(to) or is_nil(cc) or is_nil(bcc) do
+    raise NoRecipientError, email
   end
+  defp validate_recipients(email), do: email
 
   defp debug(email) do
     Logger.debug """

test/lib/bamboo/email_test.exs

@@ -6,9 +6,9 @@ defmodule Bamboo.EmailTest do
   test "new_email/1 returns an Email struct" do
     assert new_email == %Bamboo.Email{
       from: nil,
-      to: nil,
-      cc: nil,
-      bcc: nil,
+      to: [],
+      cc: [],
+      bcc: [],
       subject: nil,
       html_body: nil,
       text_body: nil,

test/lib/bamboo/mailer_test.exs

@@ -26,6 +26,23 @@ defmodule Bamboo.MailerTest do
     :ok
   end
 
+  test "deliver/1 raises if any of the recipients are nil" do
+    assert_raise Bamboo.Mailer.NoRecipientError, fn ->
+      refute_receive {:deliver, _, _}
+      new_email(to: nil) |> FooMailer.deliver
+    end
+
+    assert_raise Bamboo.Mailer.NoRecipientError, fn ->
+      refute_receive {:deliver, _, _}
+      new_email(bcc: nil) |> FooMailer.deliver
+    end
+
+    assert_raise Bamboo.Mailer.NoRecipientError, fn ->
+      refute_receive {:deliver, _, _}
+      new_email(cc: nil) |> FooMailer.deliver
+    end
+  end
+
   test "deliver/1 calls the adapter with the email and config" do
     FooMailer.deliver(new_email)
 

test/lib/bamboo/mandrill_adapter_test.exs

@@ -58,20 +58,29 @@ defmodule Bamboo.MandrillAdapterTest do
 
   test "raises if the api key is nil" do
     assert_raise ArgumentError, ~r/no API key set/, fn ->
-      new_email |> MailerWithBadKey.deliver
+      base_email |> MailerWithBadKey.deliver
     end
   end
 
+  test "does not send the email if there are no recipients" do
+    {:no_recipients, _} = new_email(to: [], cc: [], bcc: []) |> Mailer.deliver
+    refute_received {:fake_mandrill, _}
+
+    email_task = new_email(to: [], cc: [], bcc: []) |> Mailer.deliver_async
+    {:no_recipients, _} = Task.await(email_task)
+    refute_received {:fake_mandrill, _}
+  end
+
   test "deliver/2 sends the to the right url" do
-    new_email |> Mailer.deliver
+    base_email |> Mailer.deliver
 
     assert_receive {:fake_mandrill, %{request_path: request_path}}
 
     assert request_path == "/api/1.0/messages/send.json"
   end
 
   test "deliver/2 sends from, html and text body, subject, and headers" do
-    email = new_email(
+    email = base_email(
       from: %{name: "From", address: "from@foo.com"},
       subject: "My Subject",
       text_body: "TEXT BODY",
@@ -93,7 +102,7 @@ defmodule Bamboo.MandrillAdapterTest do
   end
 
   test "deliver_async sends asynchronously and can be awaited upon" do
-    email = new_email(
+    email = base_email(
       from: %{name: "From", address: "from@foo.com"},
       subject: "My Subject",
       text_body: "TEXT BODY",
@@ -133,7 +142,7 @@ defmodule Bamboo.MandrillAdapterTest do
   end
 
   test "deliver/2 adds extra params to the message " do
-    email = new_email |> MandrillEmail.put_message_param("important", true)
+    email = base_email |> MandrillEmail.put_message_param("important", true)
 
     email |> Mailer.deliver
 
@@ -142,10 +151,14 @@ defmodule Bamboo.MandrillAdapterTest do
   end
 
   test "raises if the response is not a success" do
-    email = new_email(from: "INVALID_EMAIL")
+    email = base_email(from: "INVALID_EMAIL")
 
     assert_raise Bamboo.MandrillAdapter.ApiError, fn ->
       email |> Mailer.deliver
     end
   end
+
+  def base_email(attrs \\ []) do
+    new_email(to: "foo@bar.com") |> struct(attrs)
+  end
 end