Build Pyodide (WebAssembly) wheels

.github/workflows/buildwheels.yml

@@ -44,8 +44,25 @@ jobs:
           path: ./wheelhouse/*.whl
           if-no-files-found: error
 
+  build_pyodide:
+    name: Build Pyodide (WebAssembly) wheels
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Build wheels
+        uses: pypa/cibuildwheel@v4.3.5
+        env:
+          CIBW_PLATFORM: pyodide
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: wheel-artifact-pyodide
+          path: ./wheelhouse/*.whl
+          if-no-files-found: error
+
   upload_pypi:
-    needs: [build_wheels, build_sdist]
+    needs: [build_wheels, build_pyodide, build_sdist]
     runs-on: ubuntu-latest
     # Only upload to PyPI when triggered by a tag (not manual workflow_dispatch)
     if: startsWith(github.ref, 'refs/tags/')

.github/workflows/tests.yml

@@ -28,3 +28,16 @@ jobs:
 
       - name: Test
         run: python -m pytest tests -v
+
+  pyodide:
+    # WebAssembly: 32-bit, no SIMD, no threads. cibuildwheel builds the
+    # wheels and runs the tests in Node.
+    name: Pyodide (WebAssembly)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Build and test
+        uses: pypa/cibuildwheel@v4.3.5
+        env:
+          CIBW_PLATFORM: pyodide

pyproject.toml

@@ -56,6 +56,12 @@ archs = ["x86_64", "universal2", "arm64"]
 # are provided separately in the CI matrix, so each builds natively).
 archs = ["native"]
 
+[tool.cibuildwheel.pyodide]
+# WebAssembly wheels, one per Pyodide ABI (cp313: Pyodide 0.28 and 0.29;
+# cp314: Pyodide 314; cp315). In a Pyodide venv, the pytest script starts
+# with a shebang to a shell script, which macOS cannot run: python -m pytest.
+test-command = "python -m pytest {project}/tests -q"
+
 [tool.cibuildwheel.windows]
 # Build for 64-bit Windows (32-bit is rarely needed nowadays)
 archs = ["AMD64"]