add tests

.github/workflows/ci.yml

@@ -0,0 +1,19 @@
+
+name: CI
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+      - run: npm ci
+      - run: npm run lint
+      - run: npm test
+      - run: npm run build

.gitignore

@@ -1,4 +1,5 @@
 
 node_modules/
 dist/
+coverage/
 .DS_Store

.npmignore

@@ -1,4 +1,7 @@
 /node_modules
 /src
+/tests
+/coverage
 tsconfig.json
 eslint.config.js
+jest.config.js

.replit

@@ -0,0 +1,8 @@
+modules = ["nodejs-20"]
+run = "npm run watch"
+
+[nix]
+channel = "stable-24_05"
+
+[deployment]
+run = ["sh", "-c", "npm run watch"]

jest.config.js

@@ -0,0 +1,21 @@
+export default {
+  // use ts-jest/presets/default-esm to handle ECMAScript Modules
+  preset: "ts-jest/presets/default-esm",
+  testEnvironment: "node",
+  extensionsToTreatAsEsm: [".ts"],
+  moduleNameMapper: {
+    "^(\\.{1,2}/.*)\\.js$": "$1",
+  },
+  transform: {
+    "^.+\\.tsx?$": [
+      "ts-jest",
+      {
+        useESM: true,
+        tsconfig: "tsconfig.json",
+      },
+    ],
+  },
+  transformIgnorePatterns: [],
+  testMatch: ["**/tests/**/*.test.ts"],
+  resolver: 'jest-ts-webcompat-resolver',
+};