Add Jest tests and GitHub Actions workflow

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

Author: a6b8

.github/workflows/test-on-release.yml

@@ -0,0 +1,26 @@
+name: Run Tests on Release
+on: push
+permissions:
+  contents: read
+  id-token: write
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+      - name: Install dependencies
+        run: npm ci
+      - name: Run Jest tests (with coverage)
+        run: npm run test:coverage:src
+      - name: Upload coverage to Codecov (OIDC)
+        uses: codecov/codecov-action@v5
+        with:
+          use_oidc: true
+          files: ./coverage/lcov.info
+          fail_ci_if_error: true
+          flags: unittests

.gitignore

@@ -1,3 +1,4 @@
 dataTest
 node_modules
-tests/data/
+tests/data/
+coverage/

jest.config.mjs

@@ -0,0 +1,12 @@
+export default {
+    testEnvironment: 'node',
+    testMatch: ['**/tests/jest/**/*.test.mjs'],
+    collectCoverageFrom: ['src/**/*.mjs', '!src/**/*.test.mjs'],
+    coverageThreshold: {
+        global: { branches: 50, functions: 50, lines: 50, statements: 50 }
+    },
+    coverageDirectory: 'coverage',
+    coverageReporters: ['text', 'lcov', 'html', 'json'],
+    verbose: true,
+    testTimeout: 10000
+}