如何在PHP中使用phpunit模拟SimpleXMLElement？

Question

我有以下函数。

function get_svg_dimensions($svg)
    {
        $svg = simplexml_load_file($svg);
        $width = 0;
        $height = 0;

        if ($svg) {
            $attributes = $svg->attributes();

            if (isset($attributes->width, $attributes->height)) {
                $width = intval($attributes->width);
                $height = intval($attributes->height);
            } elseif (isset($attributes->viewBox)) {
                $sizes = explode(' ', $attributes->viewBox);

                if (isset($sizes[2], $sizes[3])) {
                    $width = intval($sizes[2]);
                    $height = intval($sizes[3]);
                }
            }
        }

        return ['width' => $width, 'height' => $height];
    }

我想模拟 $attributes = $svg->attributes();.

这就是测试。

public function testGetSvgDimension()
    {
        $mockAttributes = [
            'width' => '100px',
            'height' => '100px',
            'viewBox' => '0 0 100 100',
        ];

        $mockSimpleXmlElement = (object)[
            '@attributes' => $mockAttributes
        ];

        $expected_value = [
            'width' => '100px',
            'height' => '100px',
        ];

        Functions\when('simplexml_load_file')->justReturn($mockSimpleXmlElement);
        $request = $this->createMock(SimpleXMLElement::class);
        $request->expects($this->once())->method('attributes')->willReturn($mockAttributes);

        static::assertEquals($expected_value, sg_core_t_get_svg_dimensions('mock_path'));
    } 

这一行出现了以下错误 $request = $this->createMock(SimpleXMLElement::class);:

Mock_SimpleXMLElement_eba23fd5::__phpunit_setReturnValueGeneration(): Node no longer exists

我已经尝试使用 Traversable::class 而不是 SimpleXMLElement::class 在 $request = $this->createMock(Traversable::class);但在这种情况下，我得到以下警告。

Trying to configure method "attributes" which cannot be configured because it does not exist, has not been specified, is final, or is static

这是把这个函数的测试覆盖率变成了0.

PHPUnit 版本是 7.5.20. 我不能升级到8或9，因为网站是用WordPress建立的，WordPress目前只兼容于 PHPUnit 以至于 7.x. PHP 版本是 7.2.26.

谁能帮帮我？

Answer 1

找到了一个解决方案。

基本上，我做错了什么，是我在这里返回了一个错误的值。Functions\when('simplexml_load_file')->justReturn($mockSimpleXmlElement);然后试图模拟 SimpleXMLElement 类。

我应该做的是，我应该已经返回一个。SimpleXMLElement 嘲讽 simplexml_load_file 并为其添加属性。

查看完整的代码。

public function dataProvider_GetSvgDimensions()
    {
        return [
            'height and width attributes exist on the svg' => [
                (object)[
                    'width' => '100',
                    'height' => '100',
                ]
            ],
            'height and width attributes do not exist on the svg - viewBox exists' => [
                (object)[
                    'viewBox' => '0 0 100 100',
                ]
            ],
        ];
    }

    /**
     * @dataProvider dataProvider_GetSvgDimensions
     *
     * @param $mockAttributes
     */
    public function testGetSvgDimension($mockAttributes)
    {
        $expected_value = [
            'width' => '100',
            'height' => '100',
        ];

        $mockSimpleXmlElement = new SimpleXMLElement('<root />');
        foreach ($mockAttributes as $attr => $value) {
            $mockSimpleXmlElement->addAttribute($attr, $value);
        }

        Functions\when('simplexml_load_file')->justReturn($mockSimpleXmlElement);

        static::assertEquals($expected_value, sg_core_t_get_svg_dimensions('mock_path'));
    }