Example using closures as data provider in PHPUnit

FooBuilderTest.php

<?php
/**
 * @author Gerard van Helden <drm@melp.nl>
 */

class FooBuilder {
    protected $properties = array();

    function add($property, $value) {
        $this->properties[$property][] = $value;
        return $this;
    }


    function remove($property) {
        if (!empty($this->properties[$property])) {
            array_pop($this->properties[$property]);
            if (count($this->properties[$property]) == 0) {
                unset($this->properties[$property]);
            }
        }
        return $this;
    }


    function build() {
        return $this->properties;
    }
}

class FooBuilderTest extends \PHPUnit_Framework_TestCase {
    /**
     * @dataProvider builderCases
     */
    function testBuildingWithFluentInterfaceWillResultInExpectedArray($expected, $builderImpl, $description) {
        $builder = new FooBuilder();
        $this->assertEquals($expected, $builderImpl($builder)->build(), $description);
    }


    function builderCases() {
        return array(
            array(
                array(),
                function (FooBuilder $builder) {
                    return $builder;
                },
                "Initial construction"
            ),
            array(
                array('a' => array('b')),
                function (FooBuilder $builder) {
                    return $builder->add('a', 'b');
                },
                "Adding single property"
            ),
            array(
                array('a' => array('b', 'c')),
                function (FooBuilder $builder) {
                    return $builder
                        ->add('a', 'b')
                        ->add('a', 'c')
                    ;
                },
                "Adding single property twice"
            ),
            array(
                array('a' => array('b', 'c'), 'x' => array('y', 'z')),
                function (FooBuilder $builder) {
                    return $builder
                        ->add('a', 'b')
                        ->add('a', 'c')
                        ->add('x', 'y')
                        ->add('x', 'z')
                    ;
                },
                "Adding different properties multiple times"
            ),
            array(
                array('a' => array('b', 'c'), 'x' => array('y', 'z')),
                function (FooBuilder $builder) {
                    return $builder
                        ->add('a', 'b')
                        ->add('x', 'y')
                        ->add('x', 'z')
                        ->add('a', 'c')
                    ;
                },
                "Adding different properties multiple times in a different order"
            ),
            array(
                array('x' => array('y', 'z'), 'a' => array('b', 'c')),
                function (FooBuilder $builder) {
                    return $builder
                        ->add('x', 'y')
                        ->add('x', 'z')
                        ->add('a', 'b')
                        ->add('a', 'c')
                    ;
                },
                "Adding different properties multiple times in a different order"
            ),
        );
    }
}