ts-to-python

This is an experimental alternate approach to Webtypy.

WebIDL vs TypeScript as a source of truth

Webtypy ingests the webidl to produce type stubs for the Pyodide js module. ts-to-python produces the type stubs from TypeScript .d.ts files. The webidl and TypeScript type declarations contain different information. The ideal approach would combine both, but it will take some effort to implement.

What information is in the webidl but not in TypeScript declarations?

The webidls distinguish between floating point and integer types, like Python but unlike TypeScript. Using .d.ts files as our source of truth, we have no choice but to use float | int as the number type everywhere.

What information is in TypeScript declarations but not in the webidl?

TypeScript declarations include types for ECMAScript builtins. They are also available for Node and for many other packages.

Development

It seems to work with node >= 18.

Generating the types

First you must install the two subdirectories:

npm install -C type-generation-input-project
npm install -C type-generation

then to build the types, run:

npm run -C type-generation build

Running tests

You can run the unit tests for the type generation with:

npm run -C type-generation test

To run the Python tests for the generated types requires the following setup first:

cd mypy-tests
python3.11 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Then from the mypy-tests directory run pytest to run the tests.