Adds 'parallel' option support to phpcs task.

doc/tasks/phpcs.md

@@ -31,6 +31,7 @@ grumphp:
             triggered_by: [php]
             exclude: []
             show_sniffs_error_path: true
+            parallel: null
 ```
 
 **standard**
@@ -136,6 +137,13 @@ A list of rules that should not be checked. Leave this option blank to run all c
 
 Displays the sniff that triggered the error, allowing you to more easily find the specific rules with their namespaces.
 
+**parallel**
+
+*Default: null*
+
+Determines the number of processes that phpcs / phpcbf will use when running. Pass a positive integer for multiple
+processes. You can also pass the string 'auto' and it will use the number of cores / vCPUs your machine supports.
+
 ## Framework presets
 
 ### Symfony 2

src/Task/Phpcs.php

@@ -18,6 +18,7 @@
 use GrumPHP\Task\Context\RunContext;
 use Symfony\Component\Console\Exception\CommandNotFoundException;
 use Symfony\Component\OptionsResolver\OptionsResolver;
+use Symfony\Component\Process\Exception\ProcessFailedException;
 use Symfony\Component\Process\Process;
 
 /**
@@ -47,7 +48,8 @@ public static function getConfigurableOptions(): ConfigOptionsResolver
             'report' => 'full',
             'report_width' => null,
             'exclude' => [],
-            'show_sniffs_error_path' => true
+            'show_sniffs_error_path' => true,
+            'parallel' => null,
         ]);
 
         $resolver->addAllowedTypes('standard', ['array', 'null', 'string']);
@@ -64,6 +66,7 @@ public static function getConfigurableOptions(): ConfigOptionsResolver
         $resolver->addAllowedTypes('report_width', ['null', 'int']);
         $resolver->addAllowedTypes('exclude', ['array']);
         $resolver->addAllowedTypes('show_sniffs_error_path', ['bool']);
+        $resolver->addAllowedTypes('parallel', ['null', 'int', 'string']);
 
         return ConfigOptionsResolver::fromOptionsResolver($resolver);
     }
@@ -161,7 +164,76 @@ private function addArgumentsFromConfig(
         $arguments->addOptionalCommaSeparatedArgument('--ignore=%s', $config['ignore_patterns']);
         $arguments->addOptionalCommaSeparatedArgument('--exclude=%s', $config['exclude']);
         $arguments->addOptionalArgument('-s', $config['show_sniffs_error_path']);
+        $arguments->addOptionalArgument('--parallel=%s', $this->getParallelValue($config['parallel']));
 
         return $arguments;
     }
+
+    protected function getParallelValue(string|int|null $option): ?int
+    {
+        if ($option === null) {
+            return null;
+        }
+
+        if (is_string($option)) {
+            if ($option === 'auto') {
+                return $this->getNumberOfCpuCores() ?? 1;
+            }
+
+            throw new \InvalidArgumentException(
+                sprintf("When option 'parallel' is a string it can only be 'auto', got '%s'", $option)
+            );
+        }
+
+        if ($option < 1) {
+            throw new \InvalidArgumentException(
+                sprintf("When option 'parallel' is an integer it must be greater than zero, got %d", $option)
+            );
+        }
+
+        return $option;
+    }
+
+    /**
+     * @return int|null
+     */
+    protected function getNumberOfCpuCores(): ?int
+    {
+        try {
+            if (strncasecmp(PHP_OS, 'WIN', 3) === 0) {
+                $process = new Process(['wmic', 'cpu', 'get', 'NumberOfCores']);
+            }
+
+            if (strncasecmp(PHP_OS, 'Linux', 5) === 0 || strncasecmp(PHP_OS, 'Darwin', 6) === 0) {
+                $process = new Process(['nproc']);
+            }
+
+            if (!isset($process)) {
+                return null;
+            }
+
+            $process->run();
+
+            if (!$process->isSuccessful()) {
+                throw new ProcessFailedException($process);
+            }
+
+            $output = $process->getOutput();
+
+            if (strncasecmp(PHP_OS, 'WIN', 3) === 0) {
+                $lines = explode("\n", trim($output));
+                foreach ($lines as $line) {
+                    $cores = (int) trim($line);
+                    if ($cores > 0) {
+                        return $cores;
+                    }
+                }
+                return null;
+            }
+
+            return (int) trim($output);
+        } catch (\Exception) {
+            return null;
+        }
+    }
 }

test/Unit/Task/PhpcsTest.php

@@ -49,7 +49,8 @@ public function provideConfigurableOptions(): iterable
                 'report' => 'full',
                 'report_width' => null,
                 'exclude' => [],
-                'show_sniffs_error_path' => true
+                'show_sniffs_error_path' => true,
+                'parallel' => null,
             ]
         ];
     }
@@ -357,6 +358,21 @@ public function provideExternalTaskRuns(): iterable
                 $this->expectFileList('hello.php'.PHP_EOL.'hello2.php'),
             ]
         ];
+        yield 'parallel' => [
+            [
+              'parallel' => 4,
+            ],
+            $this->mockContext(RunContext::class, ['hello.php', 'hello2.php']),
+            'phpcs',
+            [
+                '--extensions=php',
+                '--report=full',
+                '-s',
+                '--parallel=4',
+                '--report-json',
+                $this->expectFileList('hello.php'.PHP_EOL.'hello2.php'),
+            ]
+        ];
     }
 
     private function expectFileList(string $expectedContents): callable