Assertions

The point of testing is to perform some operation, and then validate requirements about the results. This latter part is done using assertions:

define()methods

extends VestTest

func get_suite_name() -> String:
  return "pow()"

func suite():
  test("exp 0 should return 1", func():
    expect_equal(1, pow(128, 0))
  )
  test("exp 1 should return input", func():
    expect_equal(128, pow(128, 128))
  )

extends VestTest

func get_suite_name() -> String:
  return "pow()"

func test_exp_0_should_return_1():
  expect_equal(1, pow(128, 0))

func test_exp_1_should_return_inpt():
  expect_equal(128, pow(128, 128))

The example above contains multiple assertions about the results of the pow() function. If all the assertions succeed in a test case, it is considered passing. If any of the assertions fail, the test case is also considered failing.

Checking for equality is not the only available assertion.

Assert methods

Vest provides different assertion methods. Each of them take an additional message as the last parameter, that may be used as hints if the assertion fails.

expect(condition), expect_not(conditions)

Asserts that the given condition is true, fails the test otherwise. Has a negated version for asserting that the given condition is false. As these assertions are very general, it is a good practice to include a message.

Prefer more specific assert methods, as they can include more relevant data in the test report.

expect_not(array.is_empty(), 'Array was not empty!')
expect(array.size() == 3, 'Array size not as expected!')

expect_equal(), expect_not_equal()

Asserts that two values are equal. Uses Godot's builtin == operator. If the values being compared are objects implementing an equals() method, the method will be used instead.

In case the assertion fails, both values will be included in the report, to help with debugging.

Has a negated version to assert that two values are different.

expect_equal("ba" + "na".repeat(2), "banana")
expect_not_equal(2 * 2, 5)

expect_true(), expect_false()

Synonyms of expect() and expect_not(). Aimed at better readability for asserting on boolean values.

expect_empty(), expect_not_empty()

Asserts that a given container is empty. Godot's built-in types and objects implementing is_empty() are supported. Has a negated version.

If the assertion fails, the container will be included in the report.

expect_empty(range(1,1))
expect_not_empty(range(1, 8))

expect_contains(), expect_doesnt_contain()

Asserts that a given container includes a value. Godot built-in types and objects implementing has() are supported. Has a negated version.

If the assertion fails, the container will be included in the report.

expect_contains(range(0, 5), 3)
expect_doesnt_contain(range(2, 4), 4)