Propagate COMPOSER_MEMORY_LIMIT to script executor

src/ScriptExecutor.php

@@ -128,6 +128,10 @@ private function expandPhpScript(string $cmd): string
             $arguments[] = '--php-ini='.$ini;
         }
 
+        if ($memoryLimit = (string) getenv('COMPOSER_MEMORY_LIMIT')) {
+            $arguments[] = "-d memory_limit={$memoryLimit}";
+        }
+
         $phpArgs = implode(' ', array_map([ProcessExecutor::class, 'escape'], $arguments));
 
         return ProcessExecutor::escape($php).($phpArgs ? ' '.$phpArgs : '').' '.$cmd;

tests/ScriptExecutorTest.php

@@ -0,0 +1,58 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Flex\Tests;
+
+use Composer\Composer;
+use Composer\IO\NullIO;
+use Composer\Util\ProcessExecutor;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Process\PhpExecutableFinder;
+use Symfony\Flex\Options;
+use Symfony\Flex\ScriptExecutor;
+
+final class ScriptExecutorTest extends TestCase
+{
+    /**
+     * @backupGlobals enabled
+     */
+    public function testMemoryLimit(): void
+    {
+        $command = './command.php';
+        $memoryLimit = '32M';
+        putenv("COMPOSER_MEMORY_LIMIT={$memoryLimit}");
+        $executorMock = $this->createMock(ProcessExecutor::class);
+        $scriptExecutor = new ScriptExecutor(new Composer(), new NullIO(), new Options(), $executorMock);
+
+        $phpFinder = new PhpExecutableFinder();
+        if (!$php = $phpFinder->find(false)) {
+            throw new \RuntimeException('The PHP executable could not be found, add it to your PATH and try again.');
+        }
+
+        $arguments = $phpFinder->findArguments();
+        $ini = php_ini_loaded_file();
+        $arguments[] = "--php-ini={$ini}";
+        $arguments[] = "-d memory_limit={$memoryLimit}";
+
+        $phpArgs = implode(' ', array_map([ProcessExecutor::class, 'escape'], $arguments));
+
+        $expectedCommand = ProcessExecutor::escape($php).($phpArgs ? ' '.$phpArgs : '').' '.$command;
+
+        $executorMock
+            ->method('execute')
+            ->with($expectedCommand)
+            ->willReturn(0)
+        ;
+        $this->expectNotToPerformAssertions();
+
+        $scriptExecutor->execute('php-script', $command);
+    }
+}