ENH: Add JupyterLite CI/CD infrastructure

.circleci/config.yml

@@ -249,6 +249,21 @@ jobs:
               cp junit-results.xml doc/_build/test-results/test-doc/junit.xml;
               cp coverage.xml doc/_build/test-results/test-doc/coverage.xml;
             fi;
+      # Ensure the datasets the JupyterLite notebooks need are on disk so
+      # conf.py can copy the required subset for the build. circleci_download.sh
+      # only fetches them when the changed files reference them, so a cache miss
+      # on a PR that touches only doc/conf.py would leave them absent and the
+      # notebooks would fail at runtime with FileNotFoundError. kiloword and
+      # erp_core back the Epochs metadata tutorials (30 & 40); mtrf and eegbci
+      # back the decoding examples (receptive_field_mtrf, decoding_csp_*).
+      - run:
+          name: Ensure MNE data for JupyterLite
+          command: |
+            python -c "import mne; mne.datasets.sample.data_path(update_path=True)"
+            python -c "import mne; mne.datasets.kiloword.data_path(update_path=True)"
+            python -c "import mne; mne.datasets.erp_core.data_path(update_path=True)"
+            python -c "import mne; mne.datasets.mtrf.data_path(update_path=True)"
+            python -c "import mne; mne.datasets.eegbci.load_data(1, [6, 10, 14], update_path=True)"
       # Build docs
       - run:
           name: make html

.github/workflows/jupyterlite.yml

@@ -0,0 +1,46 @@
+name: Build JupyterLite
+
+on:  # yamllint disable-line rule:truthy
+  push:
+    branches:
+      - jupyterlite-gh-actions
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: Build JupyterLite Site
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install JupyterLite & Build Tools
+        run: |
+          python -m pip install --upgrade pip
+          pip install jupyterlite-core jupyterlite-pyodide-kernel build jupyter-server
+
+      - name: Build MNE-Python Wheel
+        run: |
+          python -m build --wheel
+          mkdir -p lite-wheels
+          cp dist/*.whl lite-wheels/
+
+      - name: Build JupyterLite Site
+        # We pass the local wheel to JupyterLite so the browser environment uses the exact code from this branch!
+        run: |
+          jupyter lite build --contents examples/ --output-dir dist_lite/ --piplite-wheel lite-wheels/*.whl
+
+      - name: Upload Artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: jupyterlite-build
+          path: dist_lite/

.gitignore

@@ -55,6 +55,7 @@ mne/viz/_brain/tests/.ipynb_checkpoints
 
 dist/
 doc/_build/
+doc/pypi/
 doc/generated/
 doc/auto_examples/
 doc/auto_tutorials/
@@ -103,3 +104,5 @@ venv/
 .hypothesis/
 .ruff_cache/
 .ipynb_checkpoints/
+jupyterlite_contents/auto_tutorials
+jupyterlite_contents/mne_data

doc/changes/dev/13925.newfeature.rst

@@ -0,0 +1 @@
+Added a JupyterLite GitHub Actions workflow to automatically build a Wasm-compatible interactive documentation site by Natneal Belete.