The Test Context

Demeanor has a concept of a test context that’s defined by the Demeanor\TestContext interface. This context object is always the first argument to any test method or callback.

The test context simply lets you pass messages back to the test case – telling it to fail, skip, expect and exception, or log a message. Additionally the context implements ArrayAccess so you can use it to store values for the duration of the test run.

Here’s an example for a unit test.

<?php
// SomeTest.php

use Demeanor\TestContext;

class SomeTest
{
    public function testStuff(TestContext $ctx)
    {
        $ctx->skip('some reason why the test is to be skipped');
    }

    public function testThisWillBeFailed(TestContext $ctx)
    {
        $ctx->fail('The reason for the failure here');
    }

    public function testLogs(TestContext $ctx)
    {
        $ctx->log('some message here');
    }

    public function testExpectException(TestContext $ctx)
    {
        $ctx->expectException('Exception');
        throw new \Exception('this does not cause the test to fail');
    }
}

Of these log is probably the more interesting. These message are not shown to the user unless they’ve cranked up the verbosity on the command line test runner (with the -v|-vv|-vvv options) or the test fails.

The same test context object that’s passed to the actually test method/callback is also passed to the before and after callbacks. This is very useful for spec-style tests.

<?php
// SomeClass.spec.php

use Demeanor\TestContext;

$this->before(function (TestContext $ctx) {
    $ctx['something'] = createSomeObjectHere();
});

$this->after(function (TestContext $ctx) {
    $ctx['something']->cleanup();
});

$this->it('should do something', function (TestContext $ctx) {
    // use $ctx['something'] here
});

Or using Annotations with unit tests.

<?php
// AnotherTest.php

use Demeanor\TestContext;

/**
 * @Before(method="setUp")
 * @After(method="tearDown")
 */
class AnotherTest
{
    public function setUp(TestContext $ctx)
    {
        $ctx['something'] = createSomeObjectHere();
    }

    public function tearDown(TestContext $ctx)
    {
        $ctx['something']->tearDown();
    }

    public function testSomething(TestContext $ctx)
    {
        // use $ctx['something']
    }
}