[lemire]

Publishes WebAssembly wheels for Pyodide, so that micropip.install("pyfusefilter") works in the browser. PyPI accepts these wheels (PEP 783 pyemscripten_*_wasm32 platform tags). The runtime dependencies, cffi and xxhash, are both available in Pyodide.

Changes

• wheels.yml: a build_pyodide job (cibuildwheel 4.3.5, CIBW_PLATFORM: pyodide), whose wheels are uploaded to PyPI with the others. One wheel per Pyodide ABI:
  • cp313-cp313-pyemscripten_2025_0_wasm32 (Pyodide 0.28, 0.29)
  • cp314-cp314-pyemscripten_2026_0_wasm32 (Pyodide 314)
  • cp315-cp315-pyemscripten_2026_5_wasm32
• pytests.yml: a Pyodide job, so pull requests build and test the WebAssembly wheels.
• pyproject-cibuildwheel.toml: [tool.cibuildwheel.pyodide] runs the tests with python -m pytest (in a Pyodide venv, the pytest script starts with a shebang to a shell script, which macOS cannot run).
• pyfusefilter/ffibuild.py: no limited API (abi3) under Emscripten. In Pyodide 315, SOABI_PLATFORM holds literal quotes, so setuptools named the extension _xorfilter.abi3-"wasm32-emscripten".so, which Python cannot import. A Pyodide wheel is tied to one Pyodide version anyway, so abi3 gains nothing there. Native builds still produce _xorfilter.abi3.so.
• tests/test_fuse8.py, tests/test_fuse16.py: sample(range(1 << 62), size) calls len() on the range, which overflows a 32-bit ssize_t (WebAssembly). The keys are drawn with randrange instead.

Checked

• The Pyodide job, as configured here, run locally with an empty cibuildwheel cache (macOS arm64): the three wheels build and pass the tests in Node (30 passed each).
• Native wheel (macOS arm64, Python 3.14): the extension is still _xorfilter.abi3.so, and the tests pass (30 passed).