symfony · nicolas-grekas · May 5, 2023 · May 3, 2023
diff --git a/src/Symfony/Component/AssetMapper/AssetMapper.php b/src/Symfony/Component/AssetMapper/AssetMapper.php
@@ -267,7 +267,7 @@ private function loadManifest(): array
         if (null === $this->manifestData) {
             $path = $this->getPublicAssetsFilesystemPath().'/'.self::MANIFEST_FILE_NAME;
 
-            if (!file_exists($path)) {
+            if (!is_file($path)) {
                 $this->manifestData = [];
             } else {
                 $this->manifestData = json_decode(file_get_contents($path), true);

diff --git a/src/Symfony/Component/AssetMapper/AssetMapperRepository.php b/src/Symfony/Component/AssetMapper/AssetMapperRepository.php
@@ -54,7 +54,7 @@ public function find(string $logicalPath): ?string
             }
 
             $file = rtrim($path, '/').'/'.$localLogicalPath;
-            if (file_exists($file)) {
+            if (is_file($file)) {
                 return realpath($file);
             }
         }

diff --git a/src/Symfony/Component/AssetMapper/Command/AssetMapperCompileCommand.php b/src/Symfony/Component/AssetMapper/Command/AssetMapperCompileCommand.php
@@ -66,13 +66,54 @@ protected function execute(InputInterface $input, OutputInterface $output): int
             throw new InvalidArgumentException(sprintf('The public directory "%s" does not exist.', $publicDir));
         }
 
+        $outputDir = $publicDir.$this->assetMapper->getPublicPrefix();
         if ($input->getOption('clean')) {
-            $outputDir = $publicDir.$this->assetMapper->getPublicPrefix();
             $io->comment(sprintf('Cleaning <info>%s</info>', $outputDir));
             $this->filesystem->remove($outputDir);
             $this->filesystem->mkdir($outputDir);
         }
 
+        $manifestPath = $publicDir.$this->assetMapper->getPublicPrefix().AssetMapper::MANIFEST_FILE_NAME;
+        if (is_file($manifestPath)) {
+            $this->filesystem->remove($manifestPath);
+        }
+        $manifest = $this->createManifestAndWriteFiles($io, $publicDir);
+        $this->filesystem->dumpFile($manifestPath, json_encode($manifest, \JSON_PRETTY_PRINT));
+        $io->comment(sprintf('Manifest written to <info>%s</info>', $manifestPath));
+
+        $importMapPath = $outputDir.ImportMapManager::IMPORT_MAP_FILE_NAME;
+        if (is_file($importMapPath)) {
+            $this->filesystem->remove($importMapPath);
+        }
+        $this->filesystem->dumpFile($importMapPath, $this->importMapManager->getImportMapJson());
+
+        $importMapPreloadPath = $outputDir.ImportMapManager::IMPORT_MAP_PRELOAD_FILE_NAME;
+        if (is_file($importMapPreloadPath)) {
+            $this->filesystem->remove($importMapPreloadPath);
+        }
+        $this->filesystem->dumpFile(
+            $importMapPreloadPath,
+            json_encode($this->importMapManager->getModulesToPreload(), \JSON_PRETTY_PRINT | \JSON_UNESCAPED_SLASHES)
+        );
+        $io->comment(sprintf('Import map written to <info>%s</info> and <info>%s</info> for quick importmap dumping onto the page.', $this->shortenPath($importMapPath), $this->shortenPath($importMapPreloadPath)));
+
+        if ($this->isDebug) {
+            $io->warning(sprintf(
+                'You are compiling assets in development. Symfony will not serve any changed assets until you delete the "%s" directory.',
+                $this->shortenPath($outputDir)
+            ));
+        }
+
+        return 0;
+    }
+
+    private function shortenPath(string $path): string
+    {
+        return str_replace($this->projectDir.'/', '', $path);
+    }
+
+    private function createManifestAndWriteFiles(SymfonyStyle $io, string $publicDir): array
+    {
         $allAssets = $this->assetMapper->allAssets();
 
         $io->comment(sprintf('Compiling <info>%d</info> assets to <info>%s%s</info>', \count($allAssets), $publicDir, $this->assetMapper->getPublicPrefix()));
@@ -88,23 +129,8 @@ protected function execute(InputInterface $input, OutputInterface $output): int
             $this->filesystem->dumpFile($targetPath, $asset->getContent());
             $manifest[$asset->logicalPath] = $asset->getPublicPath();
         }
+        ksort($manifest);
 
-        $manifestPath = $publicDir.$this->assetMapper->getPublicPrefix().AssetMapper::MANIFEST_FILE_NAME;
-        $this->filesystem->dumpFile($manifestPath, json_encode($manifest, \JSON_PRETTY_PRINT));
-        $io->comment(sprintf('Manifest written to <info>%s</info>', $manifestPath));
-
-        $importMapPath = $publicDir.$this->assetMapper->getPublicPrefix().ImportMapManager::IMPORT_MAP_FILE_NAME;
-        $this->filesystem->dumpFile($importMapPath, $this->importMapManager->getImportMapJson());
-        $io->comment(sprintf('Import map written to <info>%s</info>', $importMapPath));
-
-        if ($this->isDebug) {
-            $io->warning(sprintf(
-                'You are compiling assets in development. Symfony will not serve any changed assets until you delete %s and %s.',
-                $manifestPath,
-                $importMapPath
-            ));
-        }
-
-        return 0;
+        return $manifest;
     }
 }
diff --git a/src/Symfony/Component/AssetMapper/ImportMap/ImportMapManager.php b/src/Symfony/Component/AssetMapper/ImportMap/ImportMapManager.php
@@ -49,6 +49,7 @@ class ImportMapManager
      */
     private const PACKAGE_PATTERN = '/^(?:https?:\/\/[\w\.-]+\/)?(?:(?<registry>\w+):)?(?<package>(?:@[a-z0-9-~][a-z0-9-._~]*\/)?[a-z0-9-~][a-z0-9-._~]*)(?:@(?<version>[\w\._-]+))?(?:(?<subpath>\/.*))?$/';
     public const IMPORT_MAP_FILE_NAME = 'importmap.json';
+    public const IMPORT_MAP_PRELOAD_FILE_NAME = 'importmap.preload.json';
 
     private array $importMapEntries;
     private array $modulesToPreload;
@@ -125,9 +126,11 @@ private function buildImportMapJson(): void
             return;
         }
 
-        $dumpedPath = $this->assetMapper->getPublicAssetsFilesystemPath().'/'.self::IMPORT_MAP_FILE_NAME;
-        if (file_exists($dumpedPath)) {
-            $this->json = file_get_contents($dumpedPath);
+        $dumpedImportMapPath = $this->assetMapper->getPublicAssetsFilesystemPath().'/'.self::IMPORT_MAP_FILE_NAME;
+        $dumpedModulePreloadPath = $this->assetMapper->getPublicAssetsFilesystemPath().'/'.self::IMPORT_MAP_PRELOAD_FILE_NAME;
+        if (is_file($dumpedImportMapPath) && is_file($dumpedModulePreloadPath)) {
+            $this->json = file_get_contents($dumpedImportMapPath);
+            $this->modulesToPreload = json_decode(file_get_contents($dumpedModulePreloadPath), true, 512, \JSON_THROW_ON_ERROR);
 
             return;
         }

diff --git a/src/Symfony/Component/AssetMapper/Tests/Command/AssetsMapperCompileCommandTest.php b/src/Symfony/Component/AssetMapper/Tests/Command/AssetsMapperCompileCommandTest.php
@@ -40,14 +40,20 @@ public function testAssetsAreCompiled()
     {
         $application = new Application($this->kernel);
 
+        $targetBuildDir = $this->kernel->getProjectDir().'/public/assets';
+        // put old "built" versions to make sure the system skips using these
+        $this->filesystem->mkdir($targetBuildDir);
+        file_put_contents($targetBuildDir.'/manifest.json', '{}');
+        file_put_contents($targetBuildDir.'/importmap.json', '{"imports": {}}');
+        file_put_contents($targetBuildDir.'/importmap.preload.json', '{}');
+
         $command = $application->find('asset-map:compile');
         $tester = new CommandTester($command);
         $res = $tester->execute([]);
         $this->assertSame(0, $res);
         // match Compiling \d+ assets
         $this->assertMatchesRegularExpression('/Compiling \d+ assets/', $tester->getDisplay());
 
-        $targetBuildDir = $this->kernel->getProjectDir().'/public/assets';
         $this->assertFileExists($targetBuildDir.'/subdir/file5-f4fdc37375c7f5f2629c5659a0579967.js');
         $this->assertSame(<<<EOF
         import '../file4.js';
@@ -57,23 +63,35 @@ public function testAssetsAreCompiled()
 
         $finder = new Finder();
         $finder->in($targetBuildDir)->files();
-        $this->assertCount(9, $finder);
+        $this->assertCount(10, $finder);
         $this->assertFileExists($targetBuildDir.'/manifest.json');
 
-        $expected = [
+        $this->assertSame([
+            'already-abcdefVWXYZ0123456789.digested.css',
             'file1.css',
             'file2.js',
             'file3.css',
-            'subdir/file6.js',
-            'subdir/file5.js',
             'file4.js',
-            'already-abcdefVWXYZ0123456789.digested.css',
-        ];
-        $actual = array_keys(json_decode(file_get_contents($targetBuildDir.'/manifest.json'), true));
-        sort($expected);
-        sort($actual);
+            'subdir/file5.js',
+            'subdir/file6.js',
+        ], array_keys(json_decode(file_get_contents($targetBuildDir.'/manifest.json'), true)));
 
-        $this->assertSame($expected, $actual);
         $this->assertFileExists($targetBuildDir.'/importmap.json');
+        $actualImportMap = json_decode(file_get_contents($targetBuildDir.'/importmap.json'), true);
+        $this->assertSame([
+            '@hotwired/stimulus',
+            'lodash',
+            'file6',
+            '/assets/subdir/file5.js', // imported by file6
+            '/assets/file4.js', // imported by file5
+        ], array_keys($actualImportMap['imports']));
+
+        $this->assertFileExists($targetBuildDir.'/importmap.preload.json');
+        $actualPreload = json_decode(file_get_contents($targetBuildDir.'/importmap.preload.json'), true);
+        $this->assertCount(4, $actualPreload);
+        $this->assertStringStartsWith('https://unpkg.com/@hotwired/stimulus', $actualPreload[0]);
+        $this->assertStringStartsWith('/assets/subdir/file6-', $actualPreload[1]);
+        $this->assertStringStartsWith('/assets/subdir/file5-', $actualPreload[2]);
+        $this->assertStringStartsWith('/assets/file4-', $actualPreload[3]);
     }
 }
diff --git a/src/Symfony/Component/AssetMapper/Tests/ImportMap/ImportMapManagerTest.php b/src/Symfony/Component/AssetMapper/Tests/ImportMap/ImportMapManagerTest.php
@@ -84,6 +84,9 @@ public function testGetImportMapJsonUsesDumpedFile()
             '@hotwired/stimulus' => 'https://unpkg.com/@hotwired/stimulus@3.2.1/dist/stimulus.js',
             'app' => '/assets/app-ea9ebe6156adc038aba53164e2be0867.js',
         ]], json_decode($manager->getImportMapJson(), true));
+        $this->assertEquals([
+            '/assets/app-ea9ebe6156adc038aba53164e2be0867.js',
+        ], $manager->getModulesToPreload());
     }
 
     /**

diff --git a/src/Symfony/Component/AssetMapper/Tests/fixtures/importmap.php b/src/Symfony/Component/AssetMapper/Tests/fixtures/importmap.php
@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+return [
+    '@hotwired/stimulus' => [
+        'url' => 'https://unpkg.com/@hotwired/stimulus@3.2.1/dist/stimulus.js',
+        'preload' => true,
+    ],
+    'lodash' => [
+        'url' => 'https://ga.jspm.io/npm:lodash@4.17.21/lodash.js',
+        'preload' => false,
+    ],
+    'file6' => [
+        'path' => 'subdir/file6.js',
+        'preload' => true,
+    ],
+];
diff --git a/...fony/Component/AssetMapper/Tests/fixtures/test_public/final-assets/importmap.preload.json b/...fony/Component/AssetMapper/Tests/fixtures/test_public/final-assets/importmap.preload.json
@@ -0,0 +1,3 @@
+[
+    "/assets/app-ea9ebe6156adc038aba53164e2be0867.js"
+]