This is Not finished at all

I decided to make my own version of chess.js

But I got lazy. So instead this is just a typescript port of python-chess

The resulting javascript files (expect success.js) should be implementation independent. So it'll work in browser too. As long as your browser is recent enough.

• classes, all syntax
• 2022 features, for example .at()
• console.warn

npm install --save-dev js-python-chess

Python has the class type from which other things like bool and int subclass.

This is not how it works in JavaScript. Currently my rewrite erased my solution to this problem, which would be a bunch of functions in one file, like is_color, is_piece_type, etc.

import chess

print(chess.Color) # <class 'bool'>
print(chess.PieceType) # <class 'int'>

# type(x) for the exact type
print(type(false) is chess.Color) # True
print(type(2) is chess.PieceType) # True

# isinstance(x, type) which also supports derived types
print(isinstance(false, chess.Color)) # True
print(isinstance(2, chess.PieceType)) # True

Additionally, chess.Status is an IntFlag Enum, which subclasses both Int and Enum.

In JavaScript, there can only be one prototype per object, so I'd have to do something really crazy to implement something like this. Instead I just used TypeScript's regular Enum.

Other subtle differences:

• None is null (internally)
• __str__ is toString
• __class__ is constructor
• __repr__ et al do not have JS equivalents, they're just stored as is
• Python has overridable equality, js does not. A special python set type is provided.
• Both lists and tuples are represented with arrays
• dicts are either regular objects or Maps
• Error messages are not guaranteed to be the same but hopefully they're at least as good.

Should be the same as the latest version of python-chess