Method assertNotContains fails with string needle if array contains 0.

[kudashevs]

Q	A
PHPUnit version	8.4.3
PHP version	7.2.0
Installation Method	Composer / PHAR

Summary

I want to check that an array doesn't contain some string value.
If the array contains 0 as one of the values, assertNotContains fails assertion.

Current behavior

PHPUnit 8.4.3 by Sebastian Bergmann and contributors.

.F                                                                  2 / 2 (100%)

Time: 232 ms, Memory: 4.00 MB

There was 1 failure:

1) SomeTest::testTestWillFail
Failed asserting that an array does not contain 'test'.

E:\webserver\home\_development\www\php\sometest\tests\SomeTest.php:28

FAILURES!
Tests: 2, Assertions: 2, Failures: 1.

How to reproduce

Make fresh install of PHPUnit then execute this test:

use PHPUnit\Framework\TestCase;

class SomeTest extends TestCase
{

    public function testTestWillPass()
    {
        $arr = [
            'x' => 1,
            'y' => 1,
        ];

        $this->assertNotContains('test', $arr);
    }

    public function testTestWillFail()
    {
        $arr = [
            'x' => 1,
            'y' => 0,
        ];

        $this->assertNotContains('test', $arr);
    }
}

Was tested on 8, 7, 6 versions with same result.

Expected behavior

The second test should pass too, because array doesn't contain 'test' value.

[kudashevs]

This behavior doesn't depend on type of the array or its values. I've got the same result for indexed, associative arrays and indexed arrays with mixed data inside.

use PHPUnit\Framework\TestCase;

class SomeTest extends TestCase
{

    public function testAssociativeArrayNumbersOnlyWillPass()
    {
        $arr = [
            'x' => 1,
            'y' => 1,
        ];

        $this->assertNotContains('test', $arr);
    }

    public function testAssociativeArrayNumbersOnlyWillFail()
    {
        $arr = [
            'x' => 1,
            'y' => 0,
        ];

        $this->assertNotContains('test', $arr);
    }

    public function testIndexedArrayNumbersOnlyWillPass()
    {
        $arr = [
            1,
            1,
        ];

        $this->assertNotContains('test', $arr);
    }

    public function testIndexedArrayNumbersOnlyWillFail()
    {
        $arr = [
            1,
            0,
        ];

        $this->assertNotContains('test', $arr);
    }

    public function testIndexedArrayWithStringsWillPass()
    {
        $arr = [
            'php',
            'phpunit',
            1
        ];

        $this->assertNotContains('test', $arr);
    }

    public function testIndexedArrayWithStringsWillFail()
    {
        $arr = [
            'php',
            'phpunit',
            0,
        ];

        $this->assertNotContains('test', $arr);
    }
}

The result is:

PHPUnit 8.4.3 by Sebastian Bergmann and contributors.

.F.F.F                                                              6 / 6 (100%)

Time: 232 ms, Memory: 4.00 MB

There were 3 failures:

1) SomeTest::testAssociativeArrayNumbersOnlyWillFail
Failed asserting that an array does not contain 'test'.

E:\webserver\home\_development\www\php\sometest\tests\SomeTest.php:28

2) SomeTest::testIndexedArrayNumbersOnlyWillFail
Failed asserting that an array does not contain 'test'.

E:\webserver\home\_development\www\php\sometest\tests\SomeTest.php:48

3) SomeTest::testIndexedArrayWithStringsWillFail
Failed asserting that an array does not contain 'test'.

E:\webserver\home\_development\www\php\sometest\tests\SomeTest.php:70

FAILURES!
Tests: 6, Assertions: 6, Failures: 3.

[sebastianbergmann]

Verified. Thank you for the report.

[sebastianbergmann]

This is basically due to 0 == 'test'. This operation is performed here.

The issue can be worked around by passing true for the optional parameter $checkForNonObjectIdentityto assertContains() or assertNotContains().

[sebastianbergmann]

Unfortunately this is expected behaviour in PHPUnit 8. Starting with PHPUnit 9, due in February 2020, assertContains() will perform type-safe comparisons which will solve this problem (see #3426). In the meantime, use the optional parameters for assertContains() to force perform type-safe comparison.