Add PR build and smoke test CI

.github/workflows/ci.yml

@@ -0,0 +1,33 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  build-and-test:
+    name: Build and smoke test
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build
+        run: npm run build
+
+      - name: Test
+        run: npm test

README.md

@@ -25,6 +25,23 @@ npm run build
 
 The static site is generated in `dist/`.
 
+## Test
+
+```bash
+npm run build
+npm test
+```
+
+The test command starts `vite preview` from the built `dist/` folder and checks that the app serves both `/` and a module deep route.
+
+## CI
+
+Pull requests to `main` run GitHub Actions on Linux (`ubuntu-latest`):
+
+- `npm ci`
+- `npm run build`
+- `npm test`
+
 ## What Is Included
 
 - Ukrainian, Ukrainian+Spanish, and Spanish-only language modes.

package.json

@@ -6,7 +6,8 @@
   "scripts": {
     "dev": "vite",
     "build": "tsc -b && vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "bash scripts/smoke-test.sh"
   },
   "dependencies": {
     "lucide-react": "^0.468.0",

scripts/smoke-test.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+PORT="${PORT:-4173}"
+HOST="127.0.0.1"
+BASE_URL="http://${HOST}:${PORT}"
+LOG_FILE="${TMPDIR:-/tmp}/plusik-vite-preview.log"
+
+cleanup() {
+  if [[ -n "${SERVER_PID:-}" ]]; then
+    kill "${SERVER_PID}" >/dev/null 2>&1 || true
+  fi
+}
+trap cleanup EXIT
+
+npm run preview -- --host "${HOST}" --port "${PORT}" >"${LOG_FILE}" 2>&1 &
+SERVER_PID=$!
+
+for _ in {1..30}; do
+  if curl -fsS "${BASE_URL}/" >/dev/null 2>&1; then
+    break
+  fi
+  if ! kill -0 "${SERVER_PID}" >/dev/null 2>&1; then
+    cat "${LOG_FILE}"
+    exit 1
+  fi
+  sleep 1
+done
+
+HOME_HTML="$(curl -fsS "${BASE_URL}/")"
+MODULE_HTML="$(curl -fsS "${BASE_URL}/module/addition-no-carry")"
+
+[[ "${HOME_HTML}" == *'<div id="root">'* ]]
+[[ "${MODULE_HTML}" == *'<div id="root">'* ]]