PHPUnit: assert two arrays are equal, but order of

问题:

What is a good way to assert that two arrays of objects are equal, when the order of the elements in the array is unimportant, or even subject to change?

回答1:

The cleanest way to do this would be to extend phpunit with a new assertion method. But here's an idea for a simpler way for now. Untested code, please verify:

Somewhere in your app:

 /**
 * Determine if two associative arrays are similar
 *
 * Both arrays must have the same indexes with identical values
 * without respect to key ordering 
 * 
 * @param array $a
 * @param array $b
 * @return bool
 */
function arrays_are_similar($a, $b) {
  // if the indexes don't match, return immediately
  if (count(array_diff_assoc($a, $b))) {
    return false;
  }
  // we know that the indexes, but maybe not values, match.
  // compare the values between the two arrays
  foreach($a as $k => $v) {
    if ($v !== $b[$k]) {
      return false;
    }
  }
  // we have identical indexes, and no unequal values
  return true;
}

In your test:

$this->assertTrue(arrays_are_similar($foo, $bar));

回答2:

assertEquals method has an undocumented param $canonicalize. If you use $canonicalize = true, the arrays will be sorted by PHPUnit arrays comparator itself.

Code example:

class ArraysTest extends PHPUnit_Framework_TestCase
{
    public function testEquality()
    {
        $obj1 = $this->getObject(1);
        $obj2 = $this->getObject(2);
        $obj3 = $this->getObject(3);

        $array1 = [$obj1, $obj2, $obj3];
        $array2 = [$obj2, $obj1, $obj3];

        // Pass
        $this->assertEquals($array1, $array2, "\$canonicalize = true", 0.0, 10, true);

        // Fail
        $this->assertEquals($array1, $array2, "Default behaviour");
    }

    private function getObject($value)
    {
        $result = new stdclass();
        $result->property = $value;
        return $result;
    }
}

Arrays comparator source code at latest version of PHPUnit: https://github.com/sebastianbergmann/comparator/blob/master/src/ArrayComparator.php#L43

回答3:

My problem was that I had 2 arrays (array keys are not relevant for me, just the values).

For example I wanted to test if

$expected = array("0" => "green", "2" => "red", "5" => "blue", "9" => "pink");

had the same content (order not relevant for me) as

$actual = array("0" => "pink", "1" => "green", "3" => "yellow", "red", "blue");

So I have used array_diff.

Final result was (if the arrays are equal, the difference will result in an empty array). Please note that the difference is computed both ways (Thanks @beret, @GordonM)

$this->assertEmpty(array_merge(array_diff($expected, $actual), array_diff($actual, $expected)));

---

For a more detailed error message (while debugging), you can also test like this (thanks @DenilsonSá):

$this->assertSame(array_diff($expected, $actual), array_diff($actual, $expected));

---

Old version with bugs inside:

$this->assertEmpty(array_diff($array2, $array1));

回答4:

One other possibility:

1. Sort both arrays
2. Convert them to a string
3. Assert both strings are equal

---

$arr = array(23, 42, 108);
$exp = array(42, 23, 108);

sort($arr);
sort($exp);

$this->assertEquals(json_encode($exp), json_encode($arr));

回答5:

Simple helper method

protected function assertEqualsArrays($expected, $actual, $message) {
    $this->assertTrue(count($expected) == count(array_intersect($expected, $actual)), $message);
}

Or if you need more debug info when arrays are not equal

protected function assertEqualsArrays($expected, $actual, $message) {
    sort($expected);
    sort($actual);

    $this->assertEquals($expected, $actual, $message);
}

回答6:

If the array is sortable, I would sort them both before checking equality. If not, I would convert them to sets of some sort and compare those.

回答7:

Using array_diff():

$a1 = array(1, 2, 3);
$a2 = array(3, 2, 1);

// error when arrays don't have the same elements (order doesn't matter):
$this->assertEquals(0, count(array_diff($a1, $a2)) + count(array_diff($a2, $a1)));

Or with 2 asserts (easier to read):

// error when arrays don't have the same elements (order doesn't matter):
$this->assertEquals(0, count(array_diff($a1, $a2)));
$this->assertEquals(0, count(array_diff($a2, $a1)));

回答8:

We use the following wrapper method in our Tests:

/**
 * Assert that two arrays are equal. This helper method will sort the two arrays before comparing them if
 * necessary. This only works for one-dimensional arrays, if you need multi-dimension support, you will
 * have to iterate through the dimensions yourself.
 * @param array $expected the expected array
 * @param array $actual the actual array
 * @param bool $regard_order whether or not array elements may appear in any order, default is false
 * @param bool $check_keys whether or not to check the keys in an associative array
 */
protected function assertArraysEqual(array $expected, array $actual, $regard_order = false, $check_keys = true) {
    // check length first
    $this->assertEquals(count($expected), count($actual), 'Failed to assert that two arrays have the same length.');

    // sort arrays if order is irrelevant
    if (!$regard_order) {
        if ($check_keys) {
            $this->assertTrue(ksort($expected), 'Failed to sort array.');
            $this->assertTrue(ksort($actual), 'Failed to sort array.');
        } else {
            $this->assertTrue(sort($expected), 'Failed to sort array.');
            $this->assertTrue(sort($actual), 'Failed to sort array.');
        }
    }

    $this->assertEquals($expected, $actual);
}

回答9:

If the keys are the same but out of order this should solve it.

You just have to get the keys in the same order and compare the results.

 /**
 * Assert Array structures are the same
 *
 * @param array       $expected Expected Array
 * @param array       $actual   Actual Array
 * @param string|null $msg      Message to output on failure
 *
 * @return bool
 */
public function assertArrayStructure($expected, $actual, $msg = '') {
    ksort($expected);
    ksort($actual);
    $this->assertSame($expected, $actual, $msg);
}

回答10:

Even though you do not care about the order, it might be easier to take that into account:

Try:

asort($foo);
asort($bar);
$this->assertEquals($foo, $bar);

回答11:

The given solutions didn't do the job for me because I wanted to be able to handle multi-dimensional array and to have a clear message of what is different between the two arrays.

Here is my function

public function assertArrayEquals($array1, $array2, $rootPath = array())
{
    foreach ($array1 as $key => $value)
    {
        $this->assertArrayHasKey($key, $array2);

        if (isset($array2[$key]))
        {
            $keyPath = $rootPath;
            $keyPath[] = $key;

            if (is_array($value))
            {
                $this->assertArrayEquals($value, $array2[$key], $keyPath);
            }
            else
            {
                $this->assertEquals($value, $array2[$key], "Failed asserting that `".$array2[$key]."` matches expected `$value` for path `".implode(" > ", $keyPath)."`.");
            }
        }
    }
}

Then to use it

$this->assertArrayEquals($array1, $array2, array("/"));

回答12:

I wrote some simple code to first get all the keys from a multi-dimensional array:

 /**
 * Returns all keys from arrays with any number of levels
 * @param  array
 * @return array
 */
protected function getAllArrayKeys($array)
{
    $keys = array();
    foreach ($array as $key => $element) {
        $keys[] = $key;
        if (is_array($array[$key])) {
            $keys = array_merge($keys, $this->getAllArrayKeys($array[$key]));
        }
    }
    return $keys;
}

Then to test that they were structured the same regardless of the order of keys:

    $expectedKeys = $this->getAllArrayKeys($expectedData);
    $actualKeys = $this->getAllArrayKeys($actualData);
    $this->assertEmpty(array_diff($expectedKeys, $actualKeys));

HTH

回答13:

If values are just int or strings, and no multiple level arrays....

Why not just sorting the arrays, convert them to string...

    $mapping = implode(',', array_sort($myArray));

    $list = implode(',', array_sort($myExpectedArray));

... and then compare string:

    $this->assertEquals($myExpectedArray, $myArray);

回答14:

If you want test only the values of the array you can do:

$this->assertEquals(array_values($arrayOne), array_values($arrayTwo));

回答15:

Another option, as if you didn't already have enough, is to combine assertArraySubset combined with assertCount to make your assertion. So, your code would look something like.

self::assertCount(EXPECTED_NUM_ELEMENT, $array); self::assertArraySubset(SUBSET, $array);

This way you are order independent but still assert that all your elements are present.