README

In some cases, you may want to mock a class's methods without using testing facility like https://github.com/padraic/mockery. This trait will let you do that.

Installation

• composer require --dev unit-testing/class-spy:dev-master
• or in require-dev block of composer.json, add "unit-testing/class-spy": "dev-master" and then run composer update

Usage

In your phpunit test, you'll create a stub of your class under test. In that stub definition, add use \UnitTesting\ClassSpy\WatchableTrait;. Your stub will be extended with the following methods:

• trackMethodCall: For any method you want to test on the stub, you can create (or override its parent) method by calling return $this->trackMethodCall(); from within the method.
• getAllMethodCalls: Returns an array of all the arguments passed to all tracked methods. The array has a list of method names as keys and an array of arguments passed to the method as the value.
• getMethodCalls($method, $index = null): Pass the method name to get the arguments passed to it. Optionally add an index (where 1 = the first call) to get the arguments for a specific call if the method was called more than once. If the argument was never called, or was not called less times than the index provided, it will return null.
• getLastMethodCall($method): Get the last set of arguments for a particular method.
• setMethodResult($method, $result): Fake a specific result to be passed back from your tracked method. If the $result parameter is an instance Closure, the Closure will be executed with the actual parameters and its result will be returned.

All of the above have their equivalents for static class methods: trackStaticMethodCall, getAllStaticMethodCalls, getStaticMethodCalls, getLastStaticMethodCall, setStaticMethodResult.

Example

<?php namespace UnitTesting\ClassSpy;

class WatchableTraitIntegrationTest extends \PHPUnit_Framework_TestCase {

	function test_WatchableTrait_TracksCalls()
	{
		$instance = new SomeTestClassStub;

		// let's make some calls to this method
		$instance->doSomething('foo');
		$instance->doSomething();
		$instance->doSomethingElse('zee');
		$instance->doSomething('baz', 'boo');

		// all the tracked method and their arguments can be retrieved with getAllMethodCalls()
		$this->assertEquals(array(
			'doSomething' => array(
				array('foo'),
				array(),
				array('baz', 'boo'),
			),
			'doSomethingElse' => array(
				array('zee'),
			),
		), $instance->getAllMethodCalls());

		// get a specific method's argument calls
		$this->assertEquals(array(
			array('foo'),
			array(),
			array('baz', 'boo'),
		), $instance->getMethodCalls('doSomething'));

		// get a specific method's argument calls with an index, remember 2 = second call
		$this->assertEquals(array(), $instance->getMethodCalls('doSomething', 2));

		// get the last argument call
		$this->assertEquals(array('baz', 'boo'), $instance->getMethodCalls('doSomething', 'last'));

		// another way to do the above
		$this->assertEquals(array('baz', 'boo'), $instance->getLastMethodCall('doSomething'));

		// trying to access a call on a tracked method with an index beyond the actual number of calls yields null
		$this->assertNull($instance->getMethodCalls('doSomething', 100));

		// something that is never called will yield null
		$this->assertNull($instance->getMethodCalls('doSomethingThatIsNotTracked'));
	}

	function test_WatchableTraitOnStatic_TracksCalls()
	{
		// let's make some calls to this method
		SomeTestClassStub::doSomethingStatic('foo');
		SomeTestClassStub::doSomethingStatic();
		SomeTestClassStub::doSomethingStatic('baz', 'boo');

		// all the tracked method and their arguments can be retrieved with getAllMethodCalls()
		$this->assertEquals(array(
			'doSomethingStatic' => array(
				array('foo'),
				array(),
				array('baz', 'boo'),
			),
		), SomeTestClassStub::getAllStaticMethodCalls());

		// don't forget to reset calls on a static for subsequent tests
		SomeTestClassStub::flushStatic();
	}

	function test_WatchableTrait_CanSetResponses()
	{
		$instance = new SomeTestClassStub;
		// let's set up a simple response
		$instance->setMethodResult('doSomething', 'same result every time');

		// it will always return same thing
		$this->assertEquals('same result every time', $instance->doSomething());
		$this->assertEquals('same result every time', $instance->doSomething('foo'));
		$this->assertEquals('same result every time', $instance->doSomething('foo', 'bar'));

		// return something based upon the parameter
		$instance->setMethodResult('doSomething', function($param)
		{
			return $param . ' result';
		});

		// it will now return value based upon our closure
		$this->assertEquals('foo result', $instance->doSomething('foo'));
		$this->assertEquals('bar result', $instance->doSomething('bar'));
	}
}

class SomeTestClassStub {
	// add this trait to set this class up for testing
	use \UnitTesting\ClassSpy\WatchableTrait;

	public function doSomething()
	{
		// this will actuall track the method and its arguments.
		// Be sure to return its value if you want to mock some return values.
		return $this->trackMethodCall();
	}

	public function doSomethingElse()
	{
		// we'll just set up another one the same as above for illustration purposes.
		return $this->trackMethodCall();
	}

	public static function doSomethingStatic()
	{
		// we'll do the same for a static method
		return self::trackStaticMethodCall();
	}
}