Ensure json translation files are valid (#129)

Author: okaufmann

src/Mariuzzo/LaravelJsLocalization/Generators/LangJsGenerator.php

@@ -2,6 +2,7 @@
 
 namespace Mariuzzo\LaravelJsLocalization\Generators;
 
+use InvalidArgumentException;
 use Illuminate\Filesystem\Filesystem as File;
 use Illuminate\Support\Str;
 use JShrink\Minifier;
@@ -149,6 +150,10 @@ protected function getMessages()
                 $key = $key.$this->stringsDomain;
                 $fileContent = file_get_contents($fullPath);
                 $messages[$key] = json_decode($fileContent, true);
+
+                if (json_last_error() !== JSON_ERROR_NONE) {
+                    throw new InvalidArgumentException('Error while decode ' . basename($fullPath) . ': ' . json_last_error_msg());
+                }
             }
         }