feat: add tests

package.json

@@ -21,6 +21,7 @@
   "scripts": {
     "docs": "cp ./README.md ./dist/README.md",
     "build": "rimraf ./dist/lib && tsc --project tsconfig.build.json",
-    "up": "yarn docs && yarn build && yarn publish dist"
+    "up": "yarn docs && yarn build && yarn publish dist",
+    "test": "ts-node ./src/test/index.ts"
   }
 }