fix license metadata and update workflow

Author: blink1073

.github/workflows/build.yml

@@ -8,46 +8,21 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        python-version: ["3.7", "3.10"]
     steps:
       - name: Checkout
         uses: actions/checkout@v2
 
-      - name: Install node
-        uses: actions/setup-node@v2
-        with:
-          node-version: "12.x"
-
-      - name: Install Python
-        uses: actions/setup-python@v2
-        with:
-          python-version: "3.7"
-          architecture: "x64"
-
-      - name: Setup pip cache
-        uses: actions/cache@v2
-        with:
-          path: ~/.cache/pip
-          key: pip-3.7-${{ hashFiles('package.json') }}
-          restore-keys: |
-            pip-3.7-
-            pip-
-
-      - name: Get npm cache directory
-        id: npm-cache
-        run: |
-          echo "::set-output name=dir::$(npm config get cache)"
-
-      - uses: actions/cache@v2
-        with:
-          path: ${{ steps.npm-cache.outputs.dir }}
-          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
-          restore-keys: |
-            ${{ runner.os }}-node-
+      - uses: jupyterlab/maintainer-tools/.github/base-setup@v1
 
       - name: Install dependencies
         run: |
-          python -m pip install -U pip setuptools cookiecutter
+          python -m pip install -U cookiecutter
 
       - name: Test the extension
         run: |
@@ -68,13 +43,8 @@ jobs:
           python -m pytest --check-links
           popd
 
-      - name: Make a non-local install so the data_files get populated
+      - name: Validate extension usage
         run: |
-          pip uninstall -y jupyter_widget_testwidgets
-          pushd jupyter-widget-testwidgets
-
-          pip install .
-
           # Validate nbextension (enable does not use exit code):
           jupyter nbextension enable --py --sys-prefix jupyter_widget_testwidgets
           python -c "from notebook.nbextensions import validate_nbextension; import sys; sys.exit(validate_nbextension('jupyter_widget_testwidgets/extension') or 0)"

{{cookiecutter.github_project_name}}/pyproject.toml

@@ -9,8 +9,8 @@ build-backend = "hatchling.build"
 name = "{{ cookiecutter.github_project_name }}"
 description = "{{ cookiecutter.project_short_description }}"
 readme = "README.md"
-license = "BSD"
-requires-python = ">=3.6"
+license = { file = "LICENSE.txt" }
+requires-python = ">=3.7"
 authors = [
     { name = "{{ cookiecutter.author_name }}", email = "{{ cookiecutter.author_email }}" },
 ]