crtest

crtest is a simple tests module for Crystal.

Note: This was written with/for Crystal 0.4.3. The language API is not stable right now, this library might not work with future versions.

Usage

Write your code as usual, using the $TESTS global variable to check if you’re in a test environment.

For example:

# hello.cr

def hello(name)
  puts "hello #{name}"
end

hello("world") unless $TEST

Write your tests in another file, and require crtest at its top:

# hello_tests.cr

require "crtest"
require "./hello"

Tests must be enclosed in a test suit:

# declare a tests suit, with an optional name
ts = TestsSuite.new "MyTestSuite"

ts.run do |tr|
  # all your tests
end

Each test is another block:

  tr.test("an awesome feature") do |t|
    # ...
  end

t is a test runner. It has the following test methods:

• assert_equal(ref, value): pass only if both values are equal (==)
• assert_true(value): pass only if value is truthy
• assert_false(value): pass only if value is falsy
• assert_nil(value): pass only if value is nil

You can also use the lower-level method assert:

t.assert("didn't work as expected") do
  # ...
end

It takes a text to print if the test fails, and a block. The block must return a truthy value (i.e. not false or nil) to be considered as a success.