add tests

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

.eslintrc.json

@@ -1,11 +1,13 @@
 {
   "env": {
     "node": true,
-    "es2021": true
+    "es2021": true,
+    "jest": true
   },
   "extends": [
     "eslint:recommended",
     "plugin:@typescript-eslint/recommended",
+    "plugin:jest/recommended",
     "plugin:prettier/recommended"
   ],
   "parser": "@typescript-eslint/parser",
@@ -15,6 +17,7 @@
   },
   "plugins": [
     "@typescript-eslint",
+    "jest",
     "prettier"
   ]
 }