CommonNamespaces: fixed shortenUri; added basic tests

* shortenUri uses the first prefix it found and not the one with
longest URI. without the fix, results like happen: foo:bar/baz
* added tests for shortenUri and extendUri

CommonNamespaces.php

@@ -93,14 +93,39 @@ public function isShortenedUri($string)
         return false == strpos($string, '://');
     }
 
+    /**
+     * @param string $uri
+     * @return string
+     */
     public function shortenUri($uri)
     {
+        $longestNamespaceInfo = null;
+
         foreach ($this->namespaces as $ns => $nsUri) {
+            // prefix found
             if (false !== strpos($uri, $nsUri)) {
-                return str_replace($nsUri, $ns .':', $uri);
+                if (null == $longestNamespaceInfo) {
+                    $longestNamespaceInfo = array(
+                        'ns' => $ns,
+                        'nsUri' => $nsUri
+                    );
+                    continue;
+                }
+
+                if (strlen($nsUri) > strlen($longestNamespaceInfo['nsUri'])) {
+                    $longestNamespaceInfo = array(
+                        'ns' => $ns,
+                        'nsUri' => $nsUri
+                    );
+                }
             }
         }
 
+        // prefer the prefix with the longest URI to avoid results like foo:bar/fff
+        if (null !== $longestNamespaceInfo) {
+            return str_replace($longestNamespaceInfo['nsUri'], $longestNamespaceInfo['ns'] .':', $uri);
+        }
+
         return $uri;
     }
 }

Test/CommonNamespacesTest.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace Saft\Rdf\Test;
+
+use Saft\Rdf\CommonNamespaces;
+use Saft\Test\TestCase;
+
+class CommonNamespacesTest extends TestCase
+{
+    public function setUp()
+    {
+        parent::setUp();
+
+        $this->fixture = new CommonNamespaces();
+    }
+
+    /*
+     * Tests for extendUri
+     */
+
+    public function testExtendUri()
+    {
+        $this->fixture->add('foo', 'http://foo/');
+
+        $this->assertEquals('http://foo/bar', $this->fixture->extendUri('foo:bar'));
+    }
+
+    public function testExtendUriOverlappingPrefixes()
+    {
+        $this->fixture->add('foo', 'http://foo/');
+        $this->fixture->add('foo2', 'http://foo/baz/');
+
+        $this->assertEquals('http://foo/baz/bar', $this->fixture->extendUri('foo2:bar'));
+    }
+
+    /*
+     * Tests for shortenUri
+     */
+
+    public function testShortenUri()
+    {
+        $this->fixture->add('foo', 'http://foo/');
+
+        $this->assertEquals('foo:bar', $this->fixture->shortenUri('http://foo/bar'));
+    }
+
+    // test that in case you have overlapping namespace URIs, the longest will be used
+    // to avoid results like foo:bar/baz
+    public function testShortenUriOverlappingPrefixes()
+    {
+        $this->fixture->add('foo', 'http://foo/');
+        $this->fixture->add('foo2', 'http://foo/baz/');
+
+        $this->assertEquals('foo2:bar', $this->fixture->shortenUri('http://foo/baz/bar'));
+    }
+}