feature #54173 [Filesystem] Add the readFile() method (derrabus)

This PR was merged into the 7.1 branch.

Discussion
----------

[Filesystem] Add the `readFile()` method

| Q             | A
| ------------- | ---
| Branch?       | 7.1
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Issues        | Fix #47215
| License       | MIT

Our `Filesystem` class is a tool for leveraging PHP's native filesystem functions is a sane way.

For example, it provides a method `dumpFile()` which attempts to write the contents of a string to a file and throws if that attempt fails. However, it lacks a method to read the content of a file. The native function for this task, `file_get_contents()` comes with a couple of traps that I don't want to think about or step into when working with a file system:

* If reading a file fails, `file_get_contents()` returns `false` and triggers an `E_WARNING`. I need to check the return value against `false` and if I want feedback on the failure, I need to work with custom error handlers. Yuck.
* Passing the path to a directory to `file_get_contents()` is almost certainly a mistake that I would want to get an exception for. However, `file_get_contents()` will return an empty string in that case. Fun times.

With this PR, I'm proposing to add a `readFile()` method that either returns the content of a given file or throws an `IOException`. Furthermore, I'm dogfooding this method in components that already depend on the Filesystem component.

Commits
-------

632ff625ae [Filesystem] Add the readFile() method

Author: fabpot

Command/AssetsInstallCommand.php

@@ -260,7 +260,7 @@ private function getPublicDirectory(ContainerInterface $container): string
             return $defaultPublicDir;
         }
 
-        $composerConfig = json_decode(file_get_contents($composerFilePath), true);
+        $composerConfig = json_decode($this->filesystem->readFile($composerFilePath), true, flags: \JSON_THROW_ON_ERROR);
 
         return $composerConfig['extra']['public-dir'] ?? $defaultPublicDir;
     }

Command/CacheClearCommand.php

@@ -232,7 +232,7 @@ private function warmup(string $warmupDir, string $realBuildDir): void
         $search = [$warmupDir, str_replace('\\', '\\\\', $warmupDir)];
         $replace = str_replace('\\', '/', $realBuildDir);
         foreach (Finder::create()->files()->in($warmupDir) as $file) {
-            $content = str_replace($search, $replace, file_get_contents($file), $count);
+            $content = str_replace($search, $replace, $this->filesystem->readFile($file), $count);
             if ($count) {
                 file_put_contents($file, $content);
             }

DependencyInjection/FrameworkExtension.php

@@ -71,6 +71,7 @@
 use Symfony\Component\EventDispatcher\Attribute\AsEventListener;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
+use Symfony\Component\Filesystem\Filesystem;
 use Symfony\Component\Finder\Finder;
 use Symfony\Component\Finder\Glob;
 use Symfony\Component\Form\Extension\HtmlSanitizer\Type\TextTypeHtmlSanitizerExtension;
@@ -3141,7 +3142,7 @@ private function getPublicDirectory(ContainerBuilder $container): string
         }
 
         $container->addResource(new FileResource($composerFilePath));
-        $composerConfig = json_decode(file_get_contents($composerFilePath), true);
+        $composerConfig = json_decode((new Filesystem())->readFile($composerFilePath), true, flags: \JSON_THROW_ON_ERROR);
 
         return isset($composerConfig['extra']['public-dir']) ? $projectDir.'/'.$composerConfig['extra']['public-dir'] : $defaultPublicDir;
     }

Tests/Command/CacheClearCommand/CacheClearCommandTest.php

@@ -75,7 +75,7 @@ function () use ($file) {
         $kernelRef = new \ReflectionObject($this->kernel);
         $kernelFile = $kernelRef->getFileName();
         /** @var ResourceInterface[] $meta */
-        $meta = unserialize(file_get_contents($containerMetaFile));
+        $meta = unserialize($this->fs->readFile($containerMetaFile));
         $found = false;
         foreach ($meta as $resource) {
             if ((string) $resource === $kernelFile) {
@@ -93,7 +93,7 @@ function () use ($file) {
         );
         $this->assertMatchesRegularExpression(
             sprintf('/\'kernel.container_class\'\s*=>\s*\'%s\'/', $containerClass),
-            file_get_contents($containerFile),
+            $this->fs->readFile($containerFile),
             'kernel.container_class is properly set on the dumped container'
         );
     }

Tests/Secrets/SodiumVaultTest.php

@@ -21,16 +21,18 @@
 class SodiumVaultTest extends TestCase
 {
     private string $secretsDir;
+    private Filesystem $filesystem;
 
     protected function setUp(): void
     {
+        $this->filesystem = new Filesystem();
         $this->secretsDir = sys_get_temp_dir().'/sf_secrets/test/';
-        (new Filesystem())->remove($this->secretsDir);
+        $this->filesystem->remove($this->secretsDir);
     }
 
     protected function tearDown(): void
     {
-        (new Filesystem())->remove($this->secretsDir);
+        $this->filesystem->remove($this->secretsDir);
     }
 
     public function testGenerateKeys()
@@ -41,8 +43,8 @@ public function testGenerateKeys()
         $this->assertFileExists($this->secretsDir.'/test.encrypt.public.php');
         $this->assertFileExists($this->secretsDir.'/test.decrypt.private.php');
 
-        $encKey = file_get_contents($this->secretsDir.'/test.encrypt.public.php');
-        $decKey = file_get_contents($this->secretsDir.'/test.decrypt.private.php');
+        $encKey = $this->filesystem->readFile($this->secretsDir.'/test.encrypt.public.php');
+        $decKey = $this->filesystem->readFile($this->secretsDir.'/test.decrypt.private.php');
 
         $this->assertFalse($vault->generateKeys());
         $this->assertStringEqualsFile($this->secretsDir.'/test.encrypt.public.php', $encKey);

composer.json

@@ -28,7 +28,7 @@
         "symfony/http-foundation": "^6.4|^7.0",
         "symfony/http-kernel": "^6.4|^7.0",
         "symfony/polyfill-mbstring": "~1.0",
-        "symfony/filesystem": "^6.4|^7.0",
+        "symfony/filesystem": "^7.1",
         "symfony/finder": "^6.4|^7.0",
         "symfony/routing": "^6.4|^7.0"
     },