Add return values for assert and assert_equal

[britishtea]

To be consistent with assert_raise (which returns its exception), make assert and assert_equal return a value more informative than nil.

• assert will return the value it has been passed.
• assert_equal will return true. It can't return a more useful value, because 1 might be equal to 2 if #== has been redefined.

[djanowski]

assert_raise returns the exception because it's convenient when you want to further inspect the exception object. What would be the use case here?

[britishtea]

My use case is similar. I depend on the return value in a library that makes it convenient to run multiple tests with random input to test if some property holds.

Stig.property(String) do |random_string|
  assert MyLibrary.takes(random_string)
end

As long as the result of the block is truthy for all generated values, a property is considered held. If the result of the block is falsy, a property is considered not held and an exception is raised. Unfortunately, this happens when I stick a cutest assertion in the block. I prefer to use cutest's assertions for the visual feedback. Depending on a truthy/falsy value also keeps the library test-framework agnostic.

Currently, with cutest I'd have to write a wrapper function like below or lose the visual feedback.

def assert_property(*args, &block)
  Stig.property(args) { |*block_args| assert block.call(block_args) }
end

assert_property(String) do |random_string|
  MyLibrary.takes(random_string)
end