Add some basic smoke tests

.github/workflows/ci.yml

@@ -0,0 +1,49 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install Python dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e .
+          pip install pytest
+
+      - name: Run Python tests
+        run: python -m pytest tests/ -q
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+
+      - name: Install Playwright package
+        run: npm install
+
+      - name: Cache Playwright browsers
+        id: playwright-cache
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/ms-playwright
+          key: ${{ runner.os }}-playwright-${{ hashFiles('package-lock.json') }}
+
+      - name: Install Playwright browser
+        run: npx playwright install --with-deps chromium
+
+      - name: Run Playwright smoke tests
+        run: npm run test:e2e

.gitignore

@@ -1,3 +1,5 @@
+node_modules/
+test-results/
 .ipynb_checkpoints
 legacy_code/
 .DS_Store

README.md

@@ -14,4 +14,44 @@ A method for drawing ancestral recombination graphs from tskit tree sequences in
 
 Users can click and drag the nodes (including the sample) along the x-axis to further clean up the layout of the graph. The simulation does not take into account line crosses, which can often be improved with some fiddling. Once a node has been moved by a user, its position is fixed with regards to the force simulation.
 
-See [tutorial.md](https://github.com/kitchensjn/tskit_arg_visualizer/blob/main/docs/tutorial.md) for a walkthrough of the package.
+See [tutorial.md](https://github.com/kitchensjn/tskit_arg_visualizer/blob/main/docs/tutorial.md) for a walkthrough of the package.
+
+## Testing (Local and CI)
+
+This repository now includes:
+
+- Python tests (pytest), under `tests/`
+- Minimal browser smoke tests (Playwright), under `tests/playwright/`
+
+### Local setup
+
+1. Install Python dependencies and test runner:
+
+```bash
+python -m pip install --upgrade pip
+pip install -e .
+pip install pytest
+```
+
+2. Install Playwright tooling:
+
+```bash
+npm install
+npx playwright install --with-deps chromium
+```
+
+3. Run tests:
+
+```bash
+python -m pytest tests/ -q
+npm run test:e2e
+```
+
+### GitHub Actions
+
+CI is defined in `.github/workflows/ci.yml` and runs both:
+
+- `python -m pytest tests/ -q`
+- `npm run test:e2e`
+
+If commands change locally, update them in both this README and the workflow file so local and CI behavior stay aligned.

package.json

@@ -0,0 +1,14 @@
+{
+  "name": "tskit_arg_visualizer-e2e",
+  "private": true,
+  "version": "0.0.0",
+  "description": "Minimal Playwright setup for browser smoke tests",
+  "scripts": {
+    "test:e2e": "playwright test",
+    "test:e2e:headed": "playwright test --headed",
+    "test:e2e:install": "playwright install --with-deps chromium"
+  },
+  "devDependencies": {
+    "@playwright/test": "^1.54.1"
+  }
+}

playwright.config.js

@@ -0,0 +1,18 @@
+const { defineConfig } = require("@playwright/test");
+
+module.exports = defineConfig({
+  testDir: "tests/playwright",
+  timeout: 30 * 1000,
+  expect: {
+    timeout: 5 * 1000,
+  },
+  use: {
+    headless: true,
+  },
+  projects: [
+    {
+      name: "chromium",
+      use: { browserName: "chromium" },
+    },
+  ],
+});

tests/playwright/smoke.spec.js

@@ -0,0 +1,28 @@
+const { test, expect } = require("@playwright/test");
+const fs = require("fs");
+const os = require("os");
+const path = require("path");
+
+// This smoke test intentionally avoids network or project-specific runtime
+// dependencies. It verifies that Playwright is wired up and can execute
+// JavaScript in a real browser context in CI.
+test("opens local HTML and evaluates client-side JS", async ({ page }) => {
+  const html = [
+    "<!doctype html>",
+    "<html>",
+    "<head><meta charset='utf-8'><title>argviz smoke</title></head>",
+    "<body>",
+    "  <h1 id='status'>ready</h1>",
+    "  <script>",
+    "    document.getElementById('status').textContent = 'playwright-ok';",
+    "  </script>",
+    "</body>",
+    "</html>",
+  ].join("\n");
+
+  const htmlPath = path.join(os.tmpdir(), `argviz-playwright-${Date.now()}.html`);
+  fs.writeFileSync(htmlPath, html, "utf8");
+
+  await page.goto(`file://${htmlPath}`);
+  await expect(page.locator("#status")).toHaveText("playwright-ok");
+});