断言发送的邮件数量与给定的数量匹配。

def test_emails
  assert_emails 0
  ContactMailer.welcome.deliver_now
  assert_emails 1
  ContactMailer.welcome.deliver_now
  assert_emails 2
end

如果传递了块，该块应导致发送指定数量的邮件。

def test_emails_again
  assert_emails 1 do
    ContactMailer.welcome.deliver_now
  end

  assert_emails 2 do
    ContactMailer.welcome.deliver_now
    ContactMailer.welcome.deliver_later
  end
end

断言特定电子邮件已加入队列，可选择匹配参数和/或 params。

def test_email
  ContactMailer.welcome.deliver_later
  assert_enqueued_email_with ContactMailer, :welcome
end

def test_email_with_parameters
  ContactMailer.with(greeting: "Hello").welcome.deliver_later
  assert_enqueued_email_with ContactMailer, :welcome, args: { greeting: "Hello" }
end

def test_email_with_arguments
  ContactMailer.welcome("Hello", "Goodbye").deliver_later
  assert_enqueued_email_with ContactMailer, :welcome, args: ["Hello", "Goodbye"]
end

def test_email_with_named_arguments
  ContactMailer.welcome(greeting: "Hello", farewell: "Goodbye").deliver_later
  assert_enqueued_email_with ContactMailer, :welcome, args: [{ greeting: "Hello", farewell: "Goodbye" }]
end

def test_email_with_parameters_and_arguments
  ContactMailer.with(greeting: "Hello").welcome("Cheers", "Goodbye").deliver_later
  assert_enqueued_email_with ContactMailer, :welcome, params: { greeting: "Hello" }, args: ["Cheers", "Goodbye"]
end

def test_email_with_parameters_and_named_arguments
  ContactMailer.with(greeting: "Hello").welcome(farewell: "Goodbye").deliver_later
  assert_enqueued_email_with ContactMailer, :welcome, params: { greeting: "Hello" }, args: [{farewell: "Goodbye"}]
end

def test_email_with_parameterized_mailer
  ContactMailer.with(greeting: "Hello").welcome.deliver_later
  assert_enqueued_email_with ContactMailer.with(greeting: "Hello"), :welcome
end

def test_email_with_matchers
  ContactMailer.with(greeting: "Hello").welcome("Cheers", "Goodbye").deliver_later
  assert_enqueued_email_with ContactMailer, :welcome,
    params: ->(params) { /hello/i.match?(params[:greeting]) },
    args: ->(args) { /cheers/i.match?(args[0]) }
end

如果传递了块，该块应导致将指定的电子邮件加入队列。

def test_email_in_block
  assert_enqueued_email_with ContactMailer, :welcome do
    ContactMailer.welcome.deliver_later
  end
end

如果 args 被提供为 Hash，则会匹配参数化电子邮件。

def test_parameterized_email
  assert_enqueued_email_with ContactMailer, :welcome,
    args: {email: 'user@example.com'} do
    ContactMailer.with(email: 'user@example.com').welcome.deliver_later
  end
end

断言稍后发送的已加入队列的邮件数量与给定的数量匹配。

def test_emails
  assert_enqueued_emails 0
  ContactMailer.welcome.deliver_later
  assert_enqueued_emails 1
  ContactMailer.welcome.deliver_later
  assert_enqueued_emails 2
end

如果传递了块，该块应导致将指定数量的邮件加入队列。

def test_emails_again
  assert_enqueued_emails 1 do
    ContactMailer.welcome.deliver_later
  end

  assert_enqueued_emails 2 do
    ContactMailer.welcome.deliver_later
    ContactMailer.welcome.deliver_later
  end
end

断言没有发送任何电子邮件。

def test_emails
  assert_no_emails
  ContactMailer.welcome.deliver_now
  assert_emails 1
end

如果传递了块，该块不应导致发送任何电子邮件。

def test_emails_again
  assert_no_emails do
    # No emails should be sent from this block
  end
end

注意: 此断言只是一个快捷方式

assert_emails 0, &block

断言没有电子邮件被加入队列以供稍后发送。

def test_no_emails
  assert_no_enqueued_emails
  ContactMailer.welcome.deliver_later
  assert_enqueued_emails 1
end

如果提供了块，则不应导致任何电子邮件被加入队列。

def test_no_emails
  assert_no_enqueued_emails do
    # No emails should be enqueued from this block
  end
end

返回块中发送的所有电子邮件。

def test_emails
  emails = capture_emails do
    ContactMailer.welcome.deliver_now
  end
  assert_equal "Hi there", emails.first.subject

  emails = capture_emails do
    ContactMailer.welcome.deliver_now
    ContactMailer.welcome.deliver_later
  end
  assert_equal "Hi there", emails.first.subject
end

发送所有已加入队列的电子邮件。如果给出了块，则发送在块持续期间加入队列的所有电子邮件。如果未给出块，则发送测试中到目前为止已加入队列的所有电子邮件。

def test_deliver_enqueued_emails
  deliver_enqueued_emails do
    ContactMailer.welcome.deliver_later
  end

  assert_emails 1
end

def test_deliver_enqueued_emails_without_block
  ContactMailer.welcome.deliver_later

  deliver_enqueued_emails

  assert_emails 1
end

如果指定了 :queue 选项，则只执行已加入特定队列的电子邮件。

def test_deliver_enqueued_emails_with_queue
  deliver_enqueued_emails queue: :external_mailers do
    CustomerMailer.deliver_later_queue_name = :external_mailers
    CustomerMailer.welcome.deliver_later # will be performed
    EmployeeMailer.deliver_later_queue_name = :internal_mailers
    EmployeeMailer.welcome.deliver_later # will not be performed
  end

  assert_emails 1
end

如果指定了 :at 选项，则只发送立即发送或在给定时间之前发送的已加入队列的电子邮件。