Validate composer.json when composer binary is available

fixes clue#43

CHANGELOG.md

@@ -9,6 +9,10 @@ you spot any mistakes.
 *   Feature: Can now be installed as a `require-dev` composer dependency and
     supports running as `./vendor/bin/phar-composer`.
     ([#36](https://github.com/clue/phar-composer/pull/36), thanks @radford)
+*   Feature: When composer or composer.phar is available in CLI `.json` files
+    passed to `PharComposer` are validated. In case of validation errors a
+    RuntimeException will be thrown.
+    ([#36](https://github.com/clue/phar-composer/pull/48), thanks @staabm)
 
 ## 0.5.0 (2014-07-10)
 

src/Clue/PharComposer/PharComposer.php

@@ -2,13 +2,15 @@
 
 namespace Clue\PharComposer;
 
-use Symfony\Component\Finder\Finder;
-
-use Herrera\Box\StubGenerator;
 use UnexpectedValueException;
 use InvalidArgumentException;
 use RuntimeException;
+
+use Herrera\Box\StubGenerator;
+
+use Symfony\Component\Finder\Finder;
 use Symfony\Component\Finder\SplFileInfo;
+use Symfony\Component\Process\ExecutableFinder;
 
 class PharComposer
 {
@@ -247,6 +249,19 @@ public function setStep($step)
 
     private function loadJson($path)
     {
+        $executableFinder = new ExecutableFinder();
+        foreach (['composer', 'composer.phar'] as $candidateName) {
+            if ($composerPath = $executableFinder->find($candidateName, null, array(getcwd()))) {
+                $process = new Process($candidateName . ' validate '. escapeshellarg($path));
+                $process->run();
+
+                if (!$process->isSuccessful()) {
+                    throw new \RuntimeException($process->getErrorOutput());
+                }                
+                break;
+            }
+        }
+
         $ret = json_decode(file_get_contents($path), true);
         if ($ret === null) {
             var_dump(json_last_error(), JSON_ERROR_SYNTAX);

tests/PharComposerTest.php

@@ -35,6 +35,14 @@ public function testSetters(PharComposer $pharcomposer)
         return $pharcomposer;
     }
 
+    /**
+     * @expectedException RuntimeException
+     */
+    public function testComposerJsonValidation()
+    {
+        new PharComposer(__DIR__ . '/fixtures/invalid_composer.json');
+    }
+
     private function getPathProjectAbsolute($path)
     {
         return realpath(__DIR__ . '/../' . $path);

tests/fixtures/invalid_composer.json

@@ -0,0 +1,5 @@
+{
+    "name": "clue/phar-composer",
+    "description": "This file contains invalid json",
+    BAM
+}