Use separate build and test jobs and share wheel

.github/workflows/ci-emscripten.yaml

@@ -14,6 +14,15 @@ env:
   # support has not been implemented yet
   DISABLE_NUMCODECS_AVX2: 1
   DISABLE_NUMCODECS_SSE2: 1
+  # Common environment variables for both build and test jobs
+  PYODIDE_VERSION: 0.25.1
+  # PYTHON_VERSION and EMSCRIPTEN_VERSION are determined by PYODIDE_VERSION.
+  # The appropriate versions can be found in the Pyodide repodata.json
+  # "info" field, or in Makefile.envs:
+  # https://github.com/pyodide/pyodide/blob/main/Makefile.envs#L2
+  PYTHON_VERSION: 3.11.3
+  EMSCRIPTEN_VERSION: 3.1.46
+  NODE_VERSION: 18
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
@@ -24,20 +33,11 @@ permissions:
 
 jobs:
   build-wasm-emscripten:
-    name: Build numcodecs distribution for Pyodide
+    name: Build numcodecs Pyodide distribution
     runs-on: ubuntu-22.04
     # To enable this workflow on a fork, comment out:
     # FIXME: uncomment after this is ready to merge
     # if: github.repository == 'zarr-developers/numcodecs'
-    env:
-      PYODIDE_VERSION: 0.25.1
-      # PYTHON_VERSION and EMSCRIPTEN_VERSION are determined by PYODIDE_VERSION.
-      # The appropriate versions can be found in the Pyodide repodata.json
-      # "info" field, or in Makefile.envs:
-      # https://github.com/pyodide/pyodide/blob/main/Makefile.envs#L2
-      PYTHON_VERSION: 3.11.3
-      EMSCRIPTEN_VERSION: 3.1.46
-      NODE_VERSION: 18
     steps:
       - name: Checkout source
         uses: actions/checkout@v4
@@ -73,6 +73,43 @@ jobs:
         with:
           node-version: ${{ env.NODE_VERSION }}
 
+      - name: Upload Pyodide wheel artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: numcodecs-pyodide-wheel
+          path: dist/*.whl
+
+  test-wasm-emscripten:
+    name: Test numcodecs Pyodide distribution
+    runs-on: ubuntu-22.04
+    needs: [build-wasm-emscripten]
+    steps:
+      - name: Set up Python ${{ env.PYTHON_VERSION }}
+        id: setup-python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+
+      - name: Set up Emscripten toolchain
+        uses: mymindstorm/setup-emsdk@v14
+        with:
+          version: ${{ env.EMSCRIPTEN_VERSION }}
+          actions-cache-folder: emsdk-cache
+
+      - name: Install pyodide-build
+        run: python -m pip install "pydantic<2" "pyodide-build==${{ env.PYODIDE_VERSION }}"
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ env.NODE_VERSION }}
+
+      - name: Download Pyodide wheel artifact
+        uses: actions/download-artifact@v4
+        with:
+          path: dist
+          merge-multiple: true
+
       - name: Set up Pyodide virtual environment and test numcodecs for Pyodide
         run: |
           pyodide venv .venv-pyodide