Enhancement: Implement ArgumentRemovalArrayReplace mutator

[localheinz]

This PR

• Adds new feature ArgumentRemovalArrayReplace mutator
• Covered by tests
• Doc PR: Enhancement: Implement ArgumentRemovalArrayReplace mutator site#93

Related to #537.

[localheinz]

When I add the following test case

diff --git a/tests/Mutator/ArgumentRemoval/ArgumentRemovalArrayReplaceTest.php b/tests/Mutator/ArgumentRemoval/ArgumentRemovalArrayReplaceTest.php
index 69f96d2..b542f13 100644
--- a/tests/Mutator/ArgumentRemoval/ArgumentRemovalArrayReplaceTest.php
+++ b/tests/Mutator/ArgumentRemoval/ArgumentRemovalArrayReplaceTest.php
@@ -141,6 +141,29 @@ PHP
             ],
         ];

+        yield 'It mutates correctly when there is a backslash in front of array_replace' => [
+            <<<'PHP'
+<?php
+
+$a = \array_replace(['A', 1, 'C'], ['D']);
+PHP
+            ,
+            [
+                <<<'PHP'
+<?php
+
+$a = \array_replace(['D']);
+PHP
+                ,
+                <<<'PHP'
+<?php
+
+$a = \array_replace(['A', 1, 'C']);
+PHP
+                ,
+            ],
+        ];
+
         yield 'It mutates correctly when array_replace uses constants as input' => [
             <<<'PHP'
 <?php

and run

$  ./vendor/bin/phpunit tests/Mutator/ArgumentRemoval/ArgumentRemovalArrayReplaceTest.php

then the tests pass, but warnings are emitted:

PHPUnit 6.5.13 by Sebastian Bergmann and contributors.

Runtime:       PHP 7.1.22
Configuration: /Users/am/Sites/infection/infection/phpunit.xml.dist

......PHP Warning:  Unexpected character in input:  '' (ASCII=7) state=0 in - on line 3
PHP Warning:  Unexpected character in input:  '' (ASCII=7) state=0 in - on line 3
......                                                      12 / 12 (100%)

Time: 910 ms, Memory: 12.00MB

OK (12 tests, 46 assertions)

Does anyone have an idea how to sort this out?

[sanmai]

ASCII 7 aka Bell sneaked through somewhere?

[localheinz]

@sanmai

Yes, right here:

infection/tests/Mutator/AbstractMutatorTestCase.php

Line 167 in 82904f4

exec(sprintf('echo %s | php -l', escapeshellarg($realMutatedCode)), $output, $returnCode);

[sanmai]

Well, that bit just checks if a test contains a valid PHP code. It is somewhere in ArgumentRemovalArrayReplaceTest.php or ArgumentRemovalArrayReplace.php

[localheinz]

@sanmai

What do you think about 05639f3 627096f?

Copied and adjusted from the examples at http://php.net/proc_open.

[sanmai]

It should be more like this: #301 (comment)

Though I'm not entirely sure everything is in order there (proc_open is a bit tricky about closed-read pipes). So I'd make a separate function, and a test for it with a known invalid code.

static function isCodeValid($code) { ... }
function test_is_code_valid_sees_invalid_code() {  $this->assertFalse(self::isCodeValid('<?php invalid=1')); }
function assertCodeValid($code) { $this->assertTrue(self::isCodeValid($code));  }

Original argument in #301 against proc_open was that it may not be supported on all platforms. But we use Symfony's Process which does require proc_open to be present, so that's not a very valid argument: if there's not a proc_open present, you can't even run Infection itself.