add typescript

.babelrc

@@ -0,0 +1,13 @@
+{
+  "presets": [
+    [
+      "@babel/preset-env",
+      {
+        "targets": {
+          "node": "10"
+        }
+      }
+    ],
+    "@babel/preset-typescript"
+  ]
+}

.eslintrc

@@ -1,10 +1,14 @@
 {
   "parserOptions": {
-    "ecmaVersion": "2018"
+    "ecmaVersion": 2019,
+    "sourceType": "module",
+    "ecmaFeatures": {
+      "jsx": true
+    }
   },
-  "extends": ["eslint:recommended"],
+  "extends": ["eslint:recommended", "eslint-config-prettier"],
   "rules": {
-    "no-console": "off"
+    "strict": ["error", "never"]
   },
   "env": {
     "browser": true

.gitignore

@@ -1 +1,2 @@
 node_modules
+dist

.prettierrc

@@ -0,0 +1,17 @@
+{
+  "arrowParens": "avoid",
+  "bracketSpacing": false,
+  "htmlWhitespaceSensitivity": "css",
+  "insertPragma": false,
+  "jsxBracketSameLine": false,
+  "jsxSingleQuote": false,
+  "printWidth": 80,
+  "proseWrap": "always",
+  "quoteProps": "as-needed",
+  "requirePragma": false,
+  "semi": false,
+  "singleQuote": true,
+  "tabWidth": 2,
+  "trailingComma": "all",
+  "useTabs": false
+}

package.json

@@ -1,15 +1,25 @@
 {
   "name": "static-testing-tools",
-  "version": "1.0.0",
-  "description": "",
-  "main": "index.js",
+  "private": true,
+  "author": "Kent C. Dodds (http://kentcdodds.com/)",
+  "license": "GPLv3",
   "scripts": {
-    "lint": "eslint src"
+    "build": "babel src --extensions .js,.ts,.tsx --out-dir dist",
+    "lint": "eslint --ignore-path .gitignore .",
+    "check-types": "tsc",
+    "prettier": "prettier --ignore-path .gitignore \"**/*.+(js|json|ts|tsx)\"",
+    "format": "npm run prettier -- --write",
+    "check-format": "npm run prettier -- --list-different",
+    "validate": "npm run check-types && npm run check-format && npm run lint && npm run build"
   },
-  "keywords": [],
-  "author": "Kent C. Dodds <kent@doddsfamily.us> (http://kentcdodds.com/)",
-  "license": "MIT",
   "devDependencies": {
-    "eslint": "^5.5.0"
+    "@babel/cli": "^7.7.0",
+    "@babel/core": "^7.7.2",
+    "@babel/preset-env": "^7.7.1",
+    "@babel/preset-typescript": "^7.7.2",
+    "eslint": "^6.6.0",
+    "eslint-config-prettier": "^6.5.0",
+    "prettier": "^1.19.1",
+    "typescript": "^3.7.2"
   }
-}
+}

src/example.js

@@ -1,5 +1,5 @@
-const name = 'Freddy'
-typeof name === 'string'
+const username = 'freddy'
+typeof username === 'string'
 
 if (!('serviceWorker' in navigator)) {
   // you have an old browser :-(
@@ -7,5 +7,4 @@ if (!('serviceWorker' in navigator)) {
 
 const greeting = 'hello'
 console.log(`${greeting} world!`)
-
-;[(1, 2, 3)].forEach(x => console.log(x))
+;[1, 2, 3].forEach(x => console.log(x))

src/typescript-example.ts

@@ -0,0 +1,21 @@
+function add(a: number, b: number): number {
+  return a + b
+}
+
+interface User {
+  name: {
+    first: string
+    middle: string
+    last: string
+  }
+}
+function getFullName(user: User): string {
+  const {
+    name: {first, middle, last},
+  } = user
+  return [first, middle, last].filter(Boolean).join('')
+}
+
+add(1, 2)
+
+getFullName({name: {first: 'Joe', middle: 'Bud', last: 'Matthews'}})

tsconfig.json

@@ -0,0 +1,6 @@
+{
+  "compilerOptions": {
+    "noEmit": true,
+    "baseUrl": "./src"
+  }
+}