test: add unit tests (#34)

Resolves #24

## Changes

Add unit tests and run them in the GitHub actions.

.github/workflows/check.yml

@@ -31,3 +31,6 @@ jobs:
 
       - name: Lint files
         run: pnpm run lint
+
+      - name: Test files
+        run: pnpm run test

.gitignore

@@ -1,6 +1,9 @@
 # build
 dist
 
+# test
+coverage
+
 # dependencies
 node_modules
 .pnpm-debug.log*

package.json

@@ -29,12 +29,15 @@
 		"./dist/"
 	],
 	"scripts": {
+		"benchmark": "node ./utils/perf.cjs",
 		"build": "rimraf ./dist/* && concurrently \"pnpm build:cjs\" \"pnpm build:esm\"",
 		"build:cjs": "tsc -b ./tsconfig.cjs.json",
 		"build:esm": "tsc -b ./tsconfig.esm.json",
 		"format": "prettier --write \"**/*.{cjs,js,mjs,ts,json,md,mdx,yml}\"",
 		"lint": "eslint . --ext .cjs,.js,.mjs,.ts --fix --ignore-path .gitignore",
-		"prepare": "ts-node ./scripts/prepare.ts && husky install"
+		"prepare": "ts-node ./scripts/prepare.ts && husky install",
+		"test": "vitest",
+		"test:coverage": "vitest run --coverage"
 	},
 	"lint-staged": {
 		"*.{cjs,js,mjs,ts}": "eslint --fix",
@@ -54,6 +57,7 @@
 		"@mheob/prettier-config": "^3.0.1",
 		"@mheob/tsconfig": "^2.0.0",
 		"@types/node": "^18.16.16",
+		"@vitest/coverage-c8": "^0.31.2",
 		"commitizen": "^4.3.0",
 		"concurrently": "^8.0.1",
 		"cz-git": "^1.6.1",
@@ -63,7 +67,8 @@
 		"prettier": "^2.8.8",
 		"rimraf": "^5.0.1",
 		"ts-node": "^10.9.1",
-		"typescript": "^5.0.4"
+		"typescript": "^5.0.4",
+		"vitest": "^0.31.2"
 	},
 	"publishConfig": {
 		"access": "public"