feat(#3): implement initial public API tests

package.json

@@ -9,7 +9,8 @@
     "index.js"
   ],
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1",
+    "test": "jest",
+    "test:watch": "jest --watch",
     "clean": "rm -rf lib dist",
     "build": "tsc",
     "build:clean": "npm run clean && npm run build",
@@ -28,9 +29,12 @@
     "ws": "^7.4.0"
   },
   "devDependencies": {
+    "@types/jest": "^26.0.23",
     "@types/node": "^14.14.7",
     "eslint": "^7.10.0",
+    "jest": "^27.0.4",
     "source-map-loader": "^2.0.0",
+    "ts-jest": "^27.0.3",
     "ts-loader": "^8.0.11",
     "typescript": "^4.0.5",
     "webpack": "^5.4.0",