Add tests to validate referenced schemas are loaded

src/Assert.php

@@ -39,8 +39,10 @@ public static function assertJsonMatchesSchema($schema, $content)
         $retriever = new UriRetriever();
         $schema = $retriever->retrieve('file://'.realpath($schema));
 
+        // Assume references are relative to the current file
+        // Create an issue or pull request if you need more complex use cases
         $refResolver = new RefResolver($retriever);
-        $refResolver->resolve($schema, 'file://'.__DIR__.'/../Resources/schemas/');
+        $refResolver->resolve($schema, $schema->id);
 
         $validator = new Validator();
         $validator->check($content, $schema);

tests/AssertTraitTest.php

@@ -56,6 +56,26 @@ public function testAssertJsonSchemaFailMessage()
         self::assertInstanceOf('PHPUnit_Framework_ExpectationFailedException', $exception);
     }
 
+    /**
+     * Tests if referenced schemas are loaded automatically
+     */
+    public function testAssertJsonSchemaWithRefs()
+    {
+        $content = json_decode('{"code":123, "message":"Nothing works."}');
+
+        AssertTraitImpl::assertJsonMatchesSchema(self::getSchema('error.schema.json'), $content);
+    }
+
+    /**
+     * @expectedException \PHPUnit_Framework_ExpectationFailedException
+     */
+    public function testAssertJsonSchemaWithRefsFails()
+    {
+        $content = json_decode('{"code":"123", "message":"Nothing works."}');
+
+        AssertTraitImpl::assertJsonMatchesSchema(self::getSchema('error.schema.json'), $content);
+    }
+
     public function testAssertJsonMatchesSchemaString()
     {
         $content = json_decode('{"foo":123}');

tests/schemas/definitions.schema.json

@@ -0,0 +1,20 @@
+{
+  "$schema" : "http://json-schema.org/draft-04/schema#",
+  "definitions" : {
+    "link" : {
+      "type" : "object",
+      "additionalProperties" : false,
+      "properties" : {
+        "href" : { "type" : "string" }
+      }
+    },
+    "error" : {
+      "type" : "object",
+      "additionalProperties" : false,
+      "properties" : {
+        "code" : { "type" : "integer" },
+        "message" : { "type" : "string" }
+      }
+    }
+  }
+}

tests/schemas/error.schema.json

@@ -0,0 +1 @@
+{ "$ref" : "definitions.schema.json#/definitions/error" }