File::json() method to get json decoded data from a file. (#46481)

* Adds File::json() method to get json decoded data from a file.

* Update Filesystem.php

---------

Co-authored-by: Taylor Otwell <taylor@laravel.com>

src/Illuminate/Filesystem/Filesystem.php

@@ -59,6 +59,20 @@ public function get($path, $lock = false)
         throw new FileNotFoundException("File does not exist at path {$path}.");
     }
 
+    /**
+     * Get the contents of a file as decoded JSON.
+     *
+     * @param  string  $path
+     * @param  bool  $lock
+     * @return array
+     *
+     * @throws \Illuminate\Contracts\Filesystem\FileNotFoundException
+     */
+    public function json($path, $lock = false)
+    {
+        return json_decode($this->get($path, $lock), true);
+    }
+
     /**
      * Get contents of a file with shared access.
      *

tests/Filesystem/FilesystemTest.php

@@ -346,6 +346,20 @@ public function testGetRequireThrowsExceptionNonExistingFile()
         $files->getRequire(self::$tempDir.'/file.php');
     }
 
+    public function testJsonReturnsDecodedJsonData()
+    {
+        file_put_contents(self::$tempDir.'/file.json', '{"foo": "bar"}');
+        $files = new Filesystem;
+        $this->assertSame(['foo' => 'bar'], $files->json(self::$tempDir.'/file.json'));
+    }
+
+    public function testJsonReturnsNullIfJsonDataIsInvalid()
+    {
+        file_put_contents(self::$tempDir.'/file.json', '{"foo":');
+        $files = new Filesystem;
+        $this->assertNull($files->json(self::$tempDir . '/file.json'));
+    }
+
     public function testAppendAddsDataToFile()
     {
         file_put_contents(self::$tempDir.'/file.txt', 'foo');