What is the expected syntax for checking exception messages in MiniTest's assert_raises/must_raise?

Question

What is the expected syntax for checking exception messages in MiniTest\'s assert_raises/must_raise?

I\'m trying to make an assertion somet

Answer 1

Minitest does not provide (yet) you a way to check the actual exception message. But you could add a helper method that does it and extend ActiveSupport::TestCase class to use everywhere in your rails test suite, e.g.: in test_helper.rb

class ActiveSupport::TestCase
  def assert_raises_with_message(exception, msg, &block)
    block.call
  rescue exception => e
    assert_match msg, e.message
  else
    raise "Expected to raise #{exception} w/ message #{msg}, none raised"
  end
end

and use it in your tests like:

assert_raises_with_message RuntimeError, 'Foo' do
  code_that_raises_RuntimeError_with_Foo_message
end