chore: set up tests with mocha

Author: gagik

eslint.config.js

@@ -3,11 +3,17 @@ import js from "@eslint/js";
 import globals from "globals";
 import tseslint from "typescript-eslint";
 import eslintConfigPrettier from "eslint-config-prettier/flat";
+import mochaPlugin from "eslint-plugin-mocha";
 
 export default defineConfig([
     { files: ["src/**/*.ts"], plugins: { js }, extends: ["js/recommended"] },
     { files: ["src/**/*.ts"], languageOptions: { globals: globals.node } },
+    {
+        files: ["**/*.spec.ts"],
+        env: { mocha: true },
+    },
     tseslint.configs.recommended,
     eslintConfigPrettier,
     globalIgnores(["node_modules", "dist"]),
+    mochaPlugin.configs.flat.recommended,
 ]);