MC-5374: Adds static test that checks PHP compatibility

Author: jean-bernard-valentaten

composer.json

@@ -84,11 +84,13 @@
     },
     "require-dev": {
         "allure-framework/allure-phpunit": "~1.2.0",
+        "dealerdirect/phpcodesniffer-composer-installer": "^0.5.0",
         "friendsofphp/php-cs-fixer": "~2.14.0",
         "lusitanian/oauth": "~0.8.10",
         "magento/magento-coding-standard": "~4.0.0",
         "magento/magento2-functional-testing-framework": "2.5.0",
         "pdepend/pdepend": "2.5.2",
+        "phpcompatibility/php-compatibility": "^9.3",
         "phpmd/phpmd": "@stable",
         "phpunit/phpunit": "~6.5.0",
         "sebastian/phpcpd": "~3.0.0",

composer.lock

@@ -0,0 +1,22 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\TestFramework\CodingStandard\Tool;
+
+/**
+ * Defines an interface for compatibility checks against a specific version.
+ */
+interface CompatibilityInterface
+{
+    /**
+     * Sets the version against which to test code.
+     *
+     * @param string $version
+     * @return void
+     */
+    public function setTestVersion(string $version): void;
+}

dev/tests/static/framework/Magento/TestFramework/CodingStandard/Tool/CompatibilityInterface.php

@@ -0,0 +1,25 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\TestFramework\CodingStandard\Tool;
+
+/**
+ * Implements a wrapper around `phpcs` for usage with the `PHPCompatibility` sniffs against a specific PHP version.
+ */
+class PhpCompatibility extends CodeSniffer implements CompatibilityInterface
+{
+    /**
+     * Sets the version against which to test code.
+     *
+     * @param string $version
+     * @return void
+     */
+    public function setTestVersion(string $version): void
+    {
+        \PHP_CodeSniffer\Config::setConfigData('testVersion', $version);
+    }
+}

dev/tests/static/framework/Magento/TestFramework/CodingStandard/Tool/PhpCompatibility.php

@@ -8,11 +8,11 @@
 namespace Magento\Test\Php;
 
 use Magento\Framework\App\Utility\Files;
-use Magento\Framework\Component\ComponentRegistrar;
 use Magento\TestFramework\CodingStandard\Tool\CodeMessDetector;
 use Magento\TestFramework\CodingStandard\Tool\CodeSniffer;
 use Magento\TestFramework\CodingStandard\Tool\CodeSniffer\Wrapper;
 use Magento\TestFramework\CodingStandard\Tool\CopyPasteDetector;
+use Magento\TestFramework\CodingStandard\Tool\PhpCompatibility;
 use PHPMD\TextUI\Command;
 
 /**
@@ -164,6 +164,7 @@ private static function getFilesFromListFile($listsBaseDir, $listFilePattern, $n
         $listFiles = glob($globFilesListPattern);
         if (!empty($listFiles)) {
             foreach ($listFiles as $listFile) {
+                // phpcs:ignore Magento2.Performance.ForeachArrayMerge.ForeachArrayMerge
                 $filesDefinedInList = array_merge(
                     $filesDefinedInList,
                     file($listFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES)
@@ -218,9 +219,12 @@ private static function filterFiles(array $files, array $allowedFileTypes, array
             };
         } else {
             $allowedDirectories = array_map('realpath', $allowedDirectories);
-            usort($allowedDirectories, function ($dir1, $dir2) {
-                return strlen($dir1) - strlen($dir2);
-            });
+            usort(
+                $allowedDirectories,
+                function ($dir1, $dir2) {
+                    return strlen($dir1) - strlen($dir2);
+                }
+            );
             $fileIsInAllowedDirectory = function ($file) use ($allowedDirectories) {
                 foreach ($allowedDirectories as $directory) {
                     if (strpos($file, $directory) === 0) {
@@ -260,18 +264,70 @@ private function getFullWhitelist()
         }
     }
 
+    /**
+     * Retrieves the lowest PHP version specified in <kbd>composer.json</var> of project.
+     *
+     * @return string
+     */
+    private function getLowestPhpVersion(): string
+    {
+        $composerJson = json_decode(file_get_contents(BP . '/composer.json'), true);
+        $phpVersion   = '7.0';
+
+        if (isset($composerJson['require']['php'])) {
+            $versions = explode('||', $composerJson['require']['php']);
+
+            //normalize version constraints
+            foreach ($versions as $key => $version) {
+                $version = ltrim($version, '^~');
+                $version = str_replace('*', '999', $version);
+
+                $versions[$key] = $version;
+            }
+
+            //sort versions
+            usort($versions, 'version_compare');
+
+            $lowestVersion = array_shift($versions);
+            $versionParts  = explode('.', $lowestVersion);
+            $phpVersion    = sprintf('%s.%s', $versionParts[0], $versionParts[1] ?? '0');
+        }
+
+        return $phpVersion;
+    }
+
+    /**
+     * Returns whether a full scan was requested.
+     *
+     * This can be set in the `phpunit.xml` used to run these test cases, by setting the constant
+     * `TESTCODESTYLE_IS_FULL_SCAN` to `1`, e.g.:
+     * ```xml
+     * <php>
+     *     <!-- TESTCODESTYLE_IS_FULL_SCAN - specify if full scan should be performed for test code style test -->
+     *     <const name="TESTCODESTYLE_IS_FULL_SCAN" value="0"/>
+     * </php>
+     * ```
+     *
+     * @return bool
+     */
+    private function isFullScan(): bool
+    {
+        return defined('TESTCODESTYLE_IS_FULL_SCAN') && TESTCODESTYLE_IS_FULL_SCAN === '1';
+    }
+
     /**
      * Test code quality using phpcs
      */
     public function testCodeStyle()
     {
-        $isFullScan = defined('TESTCODESTYLE_IS_FULL_SCAN') && TESTCODESTYLE_IS_FULL_SCAN === '1';
         $reportFile = self::$reportDir . '/phpcs_report.txt';
         if (!file_exists($reportFile)) {
             touch($reportFile);
         }
         $codeSniffer = new CodeSniffer('Magento', $reportFile, new Wrapper());
-        $result = $codeSniffer->run($isFullScan ? $this->getFullWhitelist() : self::getWhitelist(['php', 'phtml']));
+        $result = $codeSniffer->run(
+            $this->isFullScan() ? $this->getFullWhitelist() : self::getWhitelist(['php', 'phtml'])
+        );
         $report = file_get_contents($reportFile);
         $this->assertEquals(
             0,
@@ -325,6 +381,7 @@ public function testCopyPaste()
 
         $blackList = [];
         foreach (glob(__DIR__ . '/_files/phpcpd/blacklist/*.txt') as $list) {
+            // phpcs:ignore Magento2.Performance.ForeachArrayMerge.ForeachArrayMerge
             $blackList = array_merge($blackList, file($list, FILE_IGNORE_NEW_LINES));
         }
 
@@ -380,4 +437,32 @@ public function testStrictTypes()
             . implode(PHP_EOL, $filesMissingStrictTyping)
         );
     }
+
+    /**
+     * Test for compatibility to lowest PHP version declared in <kbd>composer.json</kbd>.
+     */
+    public function testPhpCompatibility()
+    {
+        $targetVersion = $this->getLowestPhpVersion();
+        $reportFile    = self::$reportDir . '/phpcompatibility_report.txt';
+        $rulesetDir    = __DIR__ . '/_files/PHPCompatibilityMagento';
+
+        if (!file_exists($reportFile)) {
+            touch($reportFile);
+        }
+
+        $codeSniffer = new PhpCompatibility($rulesetDir, $reportFile, new Wrapper());
+        $codeSniffer->setTestVersion($targetVersion);
+
+        $result = $codeSniffer->run(
+            $this->isFullScan() ? $this->getFullWhitelist() : self::getWhitelist(['php', 'phtml'])
+        );
+        $report = file_get_contents($reportFile);
+
+        $this->assertEquals(
+            0,
+            $result,
+            'PHP Compatibility detected violation(s):' . PHP_EOL . $report
+        );
+    }
 }

dev/tests/static/testsuite/Magento/Test/Php/LiveCodeTest.php

@@ -0,0 +1,13 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+-->
+<ruleset name="PHPCompatibilityMagento">
+    <description>Magento 2 specific ruleset which checks for PHP cross version compatibility.</description>
+    <rule ref="PHPCompatibility">
+        <exclude name="PHPCompatibility.Miscellaneous.RemovedAlternativePHPTags.MaybeASPOpenTagFound" />
+    </rule>
+</ruleset>