Writing tests

Vest defines tests as a set of suites. Each suite may contain test cases, benchmarks, and even nested suites.

For example, the suite could cover the class ( unit ) being tested, with each method receiving its own suite of requirements, each being covered by a test case:

Set
├── add()
│   ├── should add unknown item
│   └── should do nothing on known item
├── has()
│   ├── should return false on empty set
│   ├── should return false on unknown item
│   └── should return true on known item
└── erase()
    ├── should erase known item
    └── should do nothing on unknown item

In this example, the Set suite has 3 subsuites, each with their own test cases.

Defining suites

Vest considers classes extending the VestTest base class as tests. Each example in the documentation will present both styles of suite definitions supported:

define()methods

extends VestTest

func suite():
  define("Test suite", func():
    test("Should do A", func(): pass)
    test("Should do B", func(): pass)
    test("Should do C", func(): pass)

    define("Nested suite", func():
      test("Should do D", func(): pass)
    )
  )

extends VestTest

func test_should_do_a():
  pass

func test_should_do_b():
  pass

func test_should_do_c():
  pass

With define

Methods whose names start with suite are considered suite definitions and are expected to use define(). The method name can be anything ( even simply suite() ), and will be called once, before running the test class.

Inside define(), use test() to define individual test cases. For nested suites, use define() inside itself. There's no limit on the amount of nesting.

As shown in the examples, test() takes a test name, and a function. This function contains the actual test case implementation.

The method name has no bearing on the suites or cases defined.

With methods

Methods whose names start with test are considered test case definitions. The test case name is derived from the method name, e.g. test_should_return_false_on_null() becomes Should Return False On Null.

The function body contains the test case implementation.

Methods don't support nested suites.

Suite name

Test classes are represented as test suites. There's different ways to set this suite's name. In order of precedence:

1. Implement get_suite_name():

   extends VestTest
   
   func get_suite_name() -> String:
     return "Example Suite"
   

2. Use class_name:

   extends VestTest
   class_name ExampleSuite
   

3. If none of the above are present, vest will use the script's path, e.g. res://tests/example_test.gd

To find out how to set test outcomes, continue reading about test outcomes and assertions.