Implement fs.readLink to read symlink target.

http://code.google.com/p/phantomjs/issues/detail?id=329

src/filesystem.cpp

@@ -220,6 +220,12 @@ QVariant FileSystem::lastModified(const QString &path) const
     return QVariant(QDateTime());
 }
 
+// Links
+QString FileSystem::readLink(const QString &path) const
+{
+    return QFileInfo(path).symLinkTarget();
+}
+
 // Tests
 bool FileSystem::exists(const QString &path) const
 {
@@ -446,6 +452,7 @@ void FileSystem::initCompletions()
     // functions
     addCompletion("list");
     addCompletion("absolute");
+    addCompletion("readLink");
     addCompletion("exists");
     addCompletion("isDirectory");
     addCompletion("isFile");

src/filesystem.h

@@ -116,6 +116,9 @@ public slots:
     bool changeWorkingDirectory(const QString &path) const;
     QString absolute(const QString &relativePath) const;
 
+    // Links
+    QString readLink(const QString &path) const;
+
     // Tests
     bool exists(const QString &path) const;
     bool isDirectory(const QString &path) const;

test/fs-spec-03.js

@@ -30,4 +30,9 @@ describe("Files and Directories API", function() {
 		fs.removeTree(TEST_DIR);
 		expect(fs.changeWorkingDirectory(START_CWD)).toBeTruthy();
 	});
-});
+
+    // TODO: test the actual functionality once we can create symlink.
+    it("should have readLink function", function() {
+        expect(typeof fs.readLink).toEqual('function');
+    });
+});