Add smoke test (playwright) for built demo image

Author: manics

.github/workflows/build.yml

@@ -244,3 +244,26 @@ jobs:
           tags: ${{ join(fromJson(steps.singleusertags.outputs.tags)) }}
           cache-from: ${{ env.CACHE_FROM }}
           cache-to: ${{ env.CACHE_TO }}
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+          cache: pip
+          cache-dependency-path: tests/dev-requirements.txt
+
+      - name: Install test dependencies
+        run: |
+          python -mpip install -r tests/dev-requirements.txt
+          python -mplaywright install chromium
+
+      - name: Test demo image
+        run: |
+          DEMO_IMAGE=${{ fromJson(steps.demotags.outputs.tags)[0] }}
+          docker run -d --name hub -p8000:8000 "$DEMO_IMAGE"
+          sleep 5
+          python -mpytest
+
+      - name: Get logs, including on failure
+        if: always()
+        run: docker logs hub

.pre-commit-config.yaml

@@ -20,6 +20,14 @@ repos:
     hooks:
       - id: prettier
 
+  # autoformat and lint Python code
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.9.4
+    hooks:
+      - id: ruff
+        args: ["--select=I", "--fix", "--show-fixes"]
+      - id: ruff-format
+
   # Static security analysis of GitHub actions https://github.com/woodruffw/zizmor
   - repo: https://github.com/woodruffw/zizmor-pre-commit
     rev: v1.5.1

tests/dev-requirements.txt

@@ -0,0 +1 @@
+pytest-playwright>=0.7.0

tests/test_demo.py

@@ -0,0 +1,17 @@
+# To run these tests with firefox:
+#   python -mpytest --browser=firefox
+# To investigate tests run this headed, and with a delay between actions
+#   python -mpytest --browser=firefox --slowmo 2000 --headed
+
+from playwright.sync_api import Page, expect
+
+
+def test_simple(page: Page) -> None:
+    page.goto("http://localhost:8000")
+    # Login page
+    expect(page.get_by_role("button", name="Sign in")).to_be_visible()
+    page.get_by_role("textbox", name="Username:").fill("demo")
+    page.get_by_role("textbox", name="Password:").fill("demo")
+    page.get_by_role("button", name="Sign in").click()
+    # JupyterLab
+    page.wait_for_url("http://localhost:8000/user/demo/lab")