feat: add code coverage with artifact upload for unit and E2E tests

Add V8 coverage for unit tests via @vitest/coverage-v8 and Istanbul
instrumentation for E2E tests via vite-plugin-istanbul. Coverage data
is collected from browser pages after each Playwright test and merged
with nyc. CI uploads both coverage reports as GitHub Actions artifacts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -46,7 +46,14 @@ jobs:
           cache: pnpm
 
       - run: pnpm install --frozen-lockfile
-      - run: pnpm test:unit
+      - run: pnpm test:unit:coverage
+
+      - uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: unit-coverage
+          path: coverage/unit/
+          retention-days: 14
 
   e2e-tests:
     name: E2E Tests
@@ -80,15 +87,21 @@ jobs:
         if: steps.playwright-cache.outputs.cache-hit == 'true'
         run: npx playwright install-deps chromium
 
-      - name: Build
+      - name: Build (with coverage instrumentation)
         run: pnpm build
         env:
           DATABASE_URL: ./data/test-crumbs.db
           NODE_ENV: test
+          VITE_COVERAGE: 'true'
 
       - run: pnpm test:e2e
         env:
           CI: true
+          VITE_COVERAGE: 'true'
+
+      - name: Merge E2E coverage
+        if: always()
+        run: npx nyc report
 
       - uses: actions/upload-artifact@v4
         if: always()
@@ -99,6 +112,13 @@ jobs:
             test-results/
           retention-days: 7
 
+      - uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: e2e-coverage
+          path: coverage/e2e/
+          retention-days: 14
+
   docker-build:
     name: Docker Build
     runs-on: ubuntu-latest

.gitignore

@@ -32,6 +32,10 @@ vite.config.ts.timestamp-*
 /test-results
 /playwright-report
 
+# Coverage
+/coverage
+.nyc_output
+
 # Claude Code
 /.claude/
 

.nycrc.json

@@ -0,0 +1,7 @@
+{
+	"report-dir": "coverage/e2e",
+	"temp-dir": "coverage/e2e/raw",
+	"reporter": ["text", "html", "lcov", "json-summary"],
+	"include": ["src/**"],
+	"exclude": ["node_modules", "tests"]
+}

Makefile

@@ -1,4 +1,5 @@
-.PHONY: help dev build preview check test test-unit test-e2e lint \
+.PHONY: help dev build preview check test test-unit test-e2e \
+	test-unit-coverage test-e2e-coverage lint \
 	db-push db-generate db-migrate db-studio docs-api \
 	install docker-build docker-up docker-down docker-logs clean \
 	release release-patch release-minor release-major
@@ -27,6 +28,12 @@ test-unit: ## Run unit tests only
 test-e2e: ## Run e2e tests only
 	pnpm test:e2e
 
+test-unit-coverage: ## Run unit tests with coverage
+	pnpm test:unit:coverage
+
+test-e2e-coverage: ## Run e2e tests with coverage
+	VITE_COVERAGE=true pnpm build && pnpm test:e2e && npx nyc report
+
 lint: ## Run linter
 	pnpm lint
 

package.json

@@ -19,7 +19,10 @@
     "check:watch": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json --watch",
     "test:unit": "vitest run",
     "test:unit:watch": "vitest",
+    "test:unit:coverage": "vitest run --coverage",
     "test:e2e": "playwright test",
+    "test:e2e:coverage": "VITE_COVERAGE=true pnpm build && pnpm test:e2e && nyc report",
+    "coverage:merge-e2e": "nyc merge coverage/e2e/raw coverage/e2e/merged.json && nyc report",
     "test": "pnpm test:unit && pnpm test:e2e",
     "db:push": "drizzle-kit push",
     "db:generate": "drizzle-kit generate",
@@ -68,13 +71,16 @@
     "@types/uuid": "^10.0.0",
     "@types/zxcvbn": "^4.4.5",
     "@vite-pwa/sveltekit": "^1.1.0",
+    "@vitest/coverage-v8": "^3.2.4",
     "drizzle-kit": "^0.31.9",
+    "nyc": "^18.0.0",
     "svelte": "^5.53.7",
     "svelte-check": "^4.4.4",
     "tailwindcss": "^4.2.1",
     "tsx": "^4.21.0",
     "typescript": "^5.9.3",
     "vite": "^7.3.1",
+    "vite-plugin-istanbul": "^7.2.1",
     "vitest": "^3.2.4",
     "yaml": "^2.8.2"
   },

tests/e2e/helpers/coverage.ts

@@ -0,0 +1,24 @@
+import { writeFileSync, mkdirSync } from 'fs';
+import { join } from 'path';
+import type { Page } from '@playwright/test';
+
+const COVERAGE_DIR = join(process.cwd(), 'coverage', 'e2e', 'raw');
+
+let counter = 0;
+
+/**
+ * Collect Istanbul coverage data from the browser page.
+ * The vite-plugin-istanbul injects `window.__coverage__` when COVERAGE=true.
+ */
+export async function collectCoverage(page: Page, testTitle: string) {
+	if (process.env.VITE_COVERAGE !== 'true') return;
+
+	const coverage = await page.evaluate(() => (window as any).__coverage__);
+	if (!coverage) return;
+
+	mkdirSync(COVERAGE_DIR, { recursive: true });
+
+	const safeName = testTitle.replace(/[^a-zA-Z0-9-_]/g, '_');
+	const filename = `coverage-${safeName}-${counter++}-${Date.now()}.json`;
+	writeFileSync(join(COVERAGE_DIR, filename), JSON.stringify(coverage));
+}

tests/e2e/helpers/fixtures.ts

@@ -1,4 +1,5 @@
 import { test as base, expect, type Page, type Locator } from '@playwright/test';
+import { collectCoverage } from './coverage';
 
 const TEST_EMAIL = 'admin@test.com';
 const TEST_PASSWORD = 'testpassword123';
@@ -13,10 +14,12 @@ export function noteCard(page: Page, title: string): Locator {
  * Extended test fixture that handles setup/auth.
  */
 export const test = base.extend<{ authenticatedPage: Page }>({
-	authenticatedPage: async ({ page }, use) => {
+	authenticatedPage: async ({ page }, use, testInfo) => {
 		// Setup: create user and login
 		await setupAndLogin(page);
 		await use(page);
+		// Teardown: collect coverage data from the browser
+		await collectCoverage(page, testInfo.title);
 	}
 });
 

vite.config.ts

@@ -1,6 +1,7 @@
 import { sveltekit } from '@sveltejs/kit/vite';
 import { SvelteKitPWA } from '@vite-pwa/sveltekit';
 import tailwindcss from '@tailwindcss/vite';
+import istanbul from 'vite-plugin-istanbul';
 import { defineConfig } from 'vite';
 
 export default defineConfig({
@@ -10,6 +11,17 @@ export default defineConfig({
 	plugins: [
 		tailwindcss(),
 		sveltekit(),
+		...(process.env.VITE_COVERAGE === 'true'
+			? [
+					istanbul({
+						include: 'src/**/*',
+						exclude: ['node_modules', 'tests/', '**/*.test.ts'],
+						extension: ['.ts', '.svelte'],
+						requireEnv: true,
+						forceBuildInstrument: true
+					})
+				]
+			: []),
 		SvelteKitPWA({
 			registerType: 'autoUpdate',
 			manifest: {

vitest.config.ts

@@ -9,6 +9,13 @@ export default defineConfig({
 	},
 	test: {
 		include: ['src/**/*.test.ts'],
-		environment: 'node'
+		environment: 'node',
+		coverage: {
+			provider: 'v8',
+			reporter: ['text', 'html', 'lcov', 'json-summary'],
+			reportsDirectory: './coverage/unit',
+			include: ['src/lib/**/*.ts'],
+			exclude: ['src/lib/**/*.test.ts', 'src/lib/types/**']
+		}
 	}
 });