Add JSDoc based types

.gitignore

@@ -1,4 +1,5 @@
 .DS_Store
+*.d.ts
 *.log
 coverage/
 node_modules/

cli.js

@@ -3,7 +3,8 @@ import fs from 'fs'
 
 import {direction} from './index.js'
 
-var pack = JSON.parse(fs.readFileSync('package.json'))
+/** @type {{[key: string]: unknown, version: string}} */
+var pack = JSON.parse(String(fs.readFileSync('package.json')))
 
 var argv = process.argv.slice(2)
 
@@ -15,7 +16,7 @@ if (argv.includes('--help') || argv.includes('-h')) {
   process.stdin.resume()
   process.stdin.setEncoding('utf8')
   process.stdin.on('data', function (data) {
-    console.log(direction(data))
+    console.log(direction(String(data)))
   })
 } else {
   console.log(direction(argv.join(' ')))

index.js

@@ -7,6 +7,12 @@ var ltrRange =
 var rtl = new RegExp('^[^' + ltrRange + ']*[' + rtlRange + ']')
 var ltr = new RegExp('^[^' + rtlRange + ']*[' + ltrRange + ']')
 
+/**
+ * Detect direction.
+ *
+ * @param {string} value
+ * @returns {'rtl' | 'ltr' | 'neutral'}
+ */
 export function direction(value) {
   var source = String(value || '')
   return rtl.test(source) ? 'rtl' : ltr.test(source) ? 'ltr' : 'neutral'

package.json

@@ -27,29 +27,31 @@
   "type": "module",
   "main": "index.js",
   "bin": "cli.js",
+  "types": "index.d.ts",
   "files": [
+    "index.d.ts",
     "index.js",
     "cli.js"
   ],
   "devDependencies": {
+    "@types/tape": "^4.0.0",
     "c8": "^7.0.0",
     "prettier": "^2.0.0",
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
+    "rimraf": "^3.0.0",
     "tape": "^5.0.0",
+    "type-coverage": "^2.0.0",
+    "typescript": "^4.0.0",
     "xo": "^0.38.0"
   },
   "scripts": {
+    "prepack": "npm run build && npm run format",
+    "build": "rimraf \"*.d.ts\" && tsc && type-coverage",
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
     "test-api": "node test.js",
     "test-coverage": "c8 --check-coverage --branches 100 --functions 100 --lines 100 --statements 100 --reporter lcov node test.js",
-    "test": "npm run format && npm run test-coverage"
-  },
-  "nyc": {
-    "check-coverage": true,
-    "lines": 100,
-    "functions": 100,
-    "branches": 100
+    "test": "npm run build && npm run format && npm run test-coverage"
   },
   "prettier": {
     "tabWidth": 2,
@@ -71,5 +73,10 @@
     "plugins": [
       "preset-wooorm"
     ]
+  },
+  "typeCoverage": {
+    "atLeast": 100,
+    "detail": true,
+    "strict": true
   }
 }

test.js

@@ -4,7 +4,8 @@ import {PassThrough} from 'stream'
 import test from 'tape'
 import {direction} from './index.js'
 
-var pkg = JSON.parse(fs.readFileSync('package.json'))
+/** @type {{[key: string]: unknown, version: string}} */
+var pkg = JSON.parse(String(fs.readFileSync('package.json')))
 
 var fixtures = [
   {input: '0', output: 'neutral'},
@@ -33,6 +34,7 @@ var fixtures = [
 test('api', function (t) {
   var index = -1
 
+  // @ts-ignore
   t.equal(direction(), 'neutral', 'should classify nullish as `neutral`')
 
   while (++index < fixtures.length) {

tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "files": ["index.js"],
+  "include": ["*.js"],
+  "compilerOptions": {
+    "target": "ES2020",
+    "lib": ["ES2020"],
+    "module": "ES2020",
+    "moduleResolution": "node",
+    "allowJs": true,
+    "checkJs": true,
+    "declaration": true,
+    "emitDeclarationOnly": true,
+    "allowSyntheticDefaultImports": true,
+    "skipLibCheck": true
+  }
+}