Create pleroma.email mix task

Closes: https://git.pleroma.social/pleroma/pleroma/issues/1061

test/tasks/email_test.exs

@@ -0,0 +1,52 @@
+defmodule Mix.Tasks.Pleroma.EmailTest do
+  use Pleroma.DataCase
+
+  import Swoosh.TestAssertions
+
+  alias Pleroma.Config
+  alias Pleroma.Tests.ObanHelpers
+
+  setup_all do
+    Mix.shell(Mix.Shell.Process)
+
+    on_exit(fn ->
+      Mix.shell(Mix.Shell.IO)
+    end)
+
+    :ok
+  end
+
+  describe "pleroma.email test" do
+    test "Sends test email with no given address" do
+      mail_to = Config.get([:instance, :email])
+
+      :ok = Mix.Tasks.Pleroma.Email.run(["test"])
+
+      ObanHelpers.perform_all()
+
+      assert_receive {:mix_shell, :info, [message]}
+      assert message =~ "Test email has been sent"
+
+      assert_email_sent(
+        to: mail_to,
+        html_body: ~r/a test email was requested./i
+      )
+    end
+
+    test "Sends test email with given address" do
+      mail_to = "hewwo@example.com"
+
+      :ok = Mix.Tasks.Pleroma.Email.run(["test", "--to", mail_to])
+
+      ObanHelpers.perform_all()
+
+      assert_receive {:mix_shell, :info, [message]}
+      assert message =~ "Test email has been sent"
+
+      assert_email_sent(
+        to: mail_to,
+        html_body: ~r/a test email was requested./i
+      )
+    end
+  end
+end