10.14 Unit testing

The Haxe Standard Library provides basic unit testing classes from the haxe.unit package.

Creating new test cases

First, create a new class extending haxe.unit.TestCase and add own test methods. Every test method name must start with "test".

class MyTestCase extends haxe.unit.TestCase {
  public function testBasic() {
    assertEquals("A", "A");
  }
}

Running unit tests

To run the test, an instance of haxe.unit.TestRunner has to be created. Add the TestCase using the add method and call run to start the test.

class Main {
  static function main() {
    var r = new haxe.unit.TestRunner();
    r.add(new MyTestCase());
    // add other TestCases here

    // finally, run the tests
    r.run();
  }
}

The result of the test looks like this:

Class: MyTestCase
.
OK 1 tests, 0 failed, 1 success

Test functions

The haxe.unit.TestCase class comes with three test functions.

• assertEquals(a, b) Succeeds if a and b are equal, where a is value tested and b is the expected value.
• assertTrue(a) Succeeds if a is true
• assertFalse(a) Succeeds if a is false

Setup and tear down

To run code before or after the test, override the functions setup and tearDown in the TestCase.

• setup is called before each test runs.
• tearDown is called once after all tests are run.

class MyTestCase extends haxe.unit.TestCase {
  var value:String;

  override public function setup() {
    value = "foo";
  }

  public function testSetup() {
    assertEquals("foo", value);
  }
}

Comparing Complex Objects

With complex objects it can be difficult to generate expected values to compare to the actual ones. It can also be a problem that assertEquals doesn't do a deep comparison. One way around these issues is to use a string as the expected value and compare it to the actual value converted to a string using Std.string. Below is a trivial example using an array.

public function testArray() {
  var actual = [1,2,3];
  assertEquals("[1, 2, 3]", Std.string(actual));
}

See the haxe.unit package on the API documentation for more details.