The ceylon.test module is a simple framework to write repeatable tests.

Tests execute the code of the module under test and can make assertions about what it does. For example,

• do functions, when called with certain arguments, return the expected results?
• do classes behave as required?
• etc.

GETTING STARTED

Tests can be written as top level functions …

test
void shouldAlwaysSucceed() {}

… or organized inside classes.

class YodaTest() {

    test
    void shouldBeJedi() {
        assert(yoda is Jedi);
    }

    test
    void shouldHavePower() {
        assert(yoda.midichloriansCount > 1k);
    }

(notice the test annotation, which helps the framework to discover tests)

ASSERTIONS

Assertions can be evaluated by using the language's assert statement or with the various assert... functions, for example:

assert(is Hobbit frodo);
assert(exists ring);

assertNotEquals(frodo, sauron);
assertThatException(() => gandalf.castLightnings()).hasType(`NotEnoughMagicPowerException`);

A test function which completes without propagating an exception is classified as a success. A test function which propagates an AssertionError is classified as a failure. A test function which propagates any other type of Exception is classified as an error.

HOOKS

Common initialization logic can be placed into separate functions, which run before or after each test.

class StarshipTest() {

    beforeTest void init() => starship.chargePhasers();

    afterTest void dispose() => starship.shutdownSystems();

Other options how to hook into tests execution, is to implement TestListener and react on concrete events. Or if you have to go deeper, there are several ceylon.test.engine.spi::TestExtension points.

DISABLING TESTS

Sometimes you want to temporarily disable a test or a group of tests, this can be done via the ignore annotation.

test
ignore("still not implemented")
void shouldBeFasterThanLight() {

Sometimes the conditions, if the test can be reliable executed, are know only in runtime, in that case one of the assume... functions can be used.

RUNNING

The most convenient way how to run tests is to use IDE integration or via command line tools ceylon test and ceylon test-js.

$ceylon test com.acme.mymodule

Tests can be also run programmatically, via interface TestRunner and its factory method createTestRunner, but this API is usually not necessary to use directly.