Add method for returning file extension

CHANGES.md

@@ -1,6 +1,7 @@
 ## 1.6.0
 * Support to run the unittests on newer versions of PHP (5.5 +)
-* Add API methods for transcoding and transformation
+* Add API methods for converting/transcoding and transformation
+* Add helper function for returning the compressed file extension
 
 ## 1.5.2
 * Fail early if version of curl/openssl is too old.

lib/Tinify/ResultMeta.php

@@ -20,4 +20,12 @@ public function height() {
     public function location() {
         return isset($this->meta["location"]) ? $this->meta["location"] : null;
     }
+
+    public function extension() {
+        if (isset($this->meta["content-type"])) {
+            $parts = explode("/", $this->meta["content-type"]);
+            return end($parts);
+        }
+        return null;
+    }
 }

test/TinifyResultTest.php

@@ -32,4 +32,14 @@ public function testWithMetaAndDataToBufferShouldReturnImageData() {
         $result = new Tinify\Result(array(), "image data");
         $this->assertSame("image data", $result->toBuffer());
     }
+
+    public function testWithMetadataReturnsExtension() {
+        $result = new Tinify\Result(array("content-type" => "image/png"), "image data");
+        $this->assertSame($result->extension(), "png");
+    }
+
+    public function testWithoutMetadataReturnsExtensionAsNull() {
+        $result = new Tinify\ResultMeta(array(), "image data");
+        $this->assertSame($result->extension(), null);
+    }
 }