DiffMatchPatch\DiffToolkitTest::testCommonOverlap PHP Method

    public function testCommonOverlap()
    {
        # Null case.
        $this->assertEquals(0, $this->dt->commontOverlap("", "abcd"));
        // Whole case.
        $this->assertEquals(3, $this->dt->commontOverlap("abc", "abcd"));
        // No overlap.
        $this->assertEquals(0, $this->dt->commontOverlap("123456", "abcd"));
        // Overlap.
        $this->assertEquals(3, $this->dt->commontOverlap("123456xxx", "xxxabcd"));
        // Unicode.
        // Some overly clever languages (C#) may treat ligatures as equal to their
        // component letters.  E.g. U+FB01 == 'fi'
        $this->assertEquals(0, $this->dt->commontOverlap("fi", json_decode('"\\ufb01"')));
    }