Phpunit mocking and chaining.

phpunit_chaining.php

<?php

namespace Foo\Unit;

class Foo
{
    public function foo($foo = true)
    {
        return $foo;
    }
}

class ChainTest extends \PHPUnit_Framework_TestCase
{
    public function testFooUndefinedMethodError()
    {
        $foo = new Foo();
        $this->assertEquals('foo', $foo->foo('foo'));

        $mock = $this->getMockBuilder('Foo\Unit\Foo')
            ->disableOriginalConstructor()
            ->getMock();
        $mock->expects($this->any())
            ->method('bar')
            ->will($this->returnValue('bar'));

        $this->assertNull($mock->foo('foo'));  // returns null by default for mocked methods when setMethods not called

        // $mock->bar();  // will throw a php fatal error
        $this->assertFalse(method_exists($mock, 'bar'));
    }

    public function testFooUndefinedMethodWorks()
    {
        $mock = $this->getMockBuilder('Foo\Unit\Foo')
            ->disableOriginalConstructor()
            ->setMethods(array('foo', 'bar'))  // mock out both methods but also an undefined method
            ->getMock();
        $mock->expects($this->any())
            ->method('bar')
            ->will($this->returnValue('bar'));

        $this->assertNull($mock->foo('foo'));

        $this->assertEquals('bar', $mock->bar());
    }

    public function testFooChained()
    {
        $mock = $this->getMockBuilder('Foo\Unit\Foo')
            ->disableOriginalConstructor()
            ->setMethods(array('bar'))  // mock out just bar so foo implementation stays the same
            ->getMock();
        $mock->expects($this->any())
            ->method('bar')
            ->will($this->returnSelf());  // return the stub object so we can chain

        $this->assertEquals('baz', $mock->bar()->foo('baz'));
    }

    public function testFooChainedAt()
    {
        $mock = $this->getMockBuilder('Foo\Foo')
            ->disableOriginalConstructor()
            ->setMethods(array('foo', 'bar', 'baz'))
            ->getMock();
        $mock->expects($this->at(4))  // on index 3 of calls, not 1 as expected, against what documentation says
            ->method('foo')
            ->will($this->returnValue('bat'));
        $mock->expects($this->any())
            ->method($this->anything())  // all other calls return self
            ->will($this->returnSelf());

        $this->assertEquals('bat', $mock->foo()->bar()->foo()->baz()->foo('foo'));
    }
}