Indexer: Add test case for the PID functions

_test/tests/inc/indexer_pid.test.php

+<?php
+/**
+ * Tests the pid functions of the indexer.
+ *
+ * @author Michael Hamann <michael@content-space.de>
+ */
+class indexer_pid_test extends DokuWikiTest {
+    function test_pid() {
+        $indexer = idx_get_indexer();
+        $syntaxPID = $indexer->getPID('wiki:syntax');
+        $this->assertEquals('wiki:syntax', $indexer->getPageFromPID($syntaxPID), 'getPageFromPID(getPID(\'wiki:syntax\')) != \'wiki:syntax\'');
+        $dokuwikiPID = $indexer->getPID('wiki:dokuwiki');
+        $this->assertEquals('wiki:syntax', $indexer->getPageFromPID($syntaxPID), 'getPageFromPID(getPID(\'wiki:syntax\')) != \'wiki:syntax\' after getting the PID for wiki:dokuwiki');
+        $this->assertEquals($syntaxPID, $indexer->getPID('wiki:syntax'), 'getPID(\'wiki:syntax\') didn\'t returned different PIDs when called twice');
+        $this->assertNotEquals($syntaxPID, $dokuwikiPID, 'Same PID returned for different pages');
+        $this->assertTrue(is_numeric($syntaxPID) && is_numeric($dokuwikiPID), 'PIDs are not numeric');
+    }
+}