Write a class that provides change directory (cd) function for an abstract file system.
Notes:
- Root path is '/'.
- Path separator is '/' by default, but can be changed.
- No end separator is used, i.e. no paths end with a /.
- Parent directory is addressable as '..'.
- Directory names consist only of English alphabet letters (A-Z and a-z).
- The function should support both relative and absolute paths.
- The function will not be passed any invalid paths.
- Do not use built-in path-related functions.
For example:
$path = new Path('/a/b/c/d');
$path->cd('../x')
echo $path->getCurrentPath();
should display /a/b/c/x.
There are tests the class should pass in the tests folder.
Document and format the code as usual, assuming production level quality.
You can use any online resources or ask for help.
In the end, create a pull request for the solution.