Convert codebase to TypeScript

.babelrc

@@ -1,6 +1,6 @@
 {
 	"presets": [
 		"@babel/preset-env",
-		"@babel/preset-flow"
+		"@babel/preset-typescript"
 	]
 }

.d.ts

@@ -0,0 +1,9 @@
+interface Model extends Object {}
+
+interface ModelDefinition extends Object {
+  [model: string]: Function
+}
+
+interface Overrides extends Object {
+  [attribute: string]: any
+}

.eslintrc

@@ -1,12 +1,11 @@
 {
-  "parser": "babel-eslint",
+  "parser": "@typescript-eslint/parser",
   "extends": [
-    "plugin:flowtype/recommended",
     "plugin:jest/recommended",
 		"standard"
   ],
   "plugins": [
-    "flowtype",
+    "@typescript-eslint",
     "jest"
 	]
 }

.travis.yml

@@ -1,4 +1,2 @@
 language: node_js
-node_js:
-  - '8'
-  - '6'
+node_js: [10, 12, 13, 14]

index.js → index.ts

@@ -1,26 +1,28 @@
-// @flow
-const faker: Faker = require('faker')
+/// <reference path=".d.ts"/>
+import faker from 'faker'
 
-const definitions: Object = {}
+const definitions: ModelDefinition = {}
 
-const factory = (model: string, count: number | Object = 1, overrides: Object = {}) => {
+const factory = (model: string, count: number | Overrides = 1, overrides: Overrides = {}): Model | Model[] => {
   if (!(model in definitions)) {
     throw new Error(`Model \`${model}\` not found.`)
   }
 
-  if (typeof count === 'object') {
+  if (typeof count !== 'number') {
     return factory(model, 1, count)
   }
 
   const resolveOverrides = (): Object => {
     const props = Object.assign({}, overrides)
+
     for (let prop in props) {
-      props[prop] = typeof props[prop] === 'function' ? props[prop].call(this, faker) : props[prop]
+      props[prop] = props[prop] instanceof Function ? props[prop].call(this, faker) : props[prop]
     }
+
     return props
   }
 
-  const generateModel = (): Object => {
+  const generateModel = (): Model => {
     return Object.assign(definitions[model](faker), resolveOverrides())
   }
 
@@ -30,15 +32,15 @@ const factory = (model: string, count: number | Object = 1, overrides: Object =
 
   return [...(function * () {
     let i = 0
-    // $FlowFixMe
+
     while (i < count) {
       yield generateModel()
       ++i
     }
   })()]
 }
 
-factory.define = (model: string, attributes: Faker => Object): factory => {
+factory.define = (model: string, attributes: (faker: Faker.FakerStatic) => Object) => {
   definitions[model] = attributes
   return factory
 }

package.json

@@ -14,16 +14,17 @@
   },
   "scripts": {
     "lint": "eslint .",
-    "flow": "flow",
-    "test": "yarn lint && yarn flow && jest --verbose",
+    "type-check": "tsc --noEmit",
+    "type-check:watch": "npm run type-check -- --watch",
+    "test": "yarn lint && jest --verbose",
     "build": "rollup -c"
   },
   "files": [
     "index.js"
   ],
   "jest": {
     "setupFilesAfterEnv": [
-      "<rootDir>/test/setup.js"
+      "<rootDir>/test/setup.ts"
     ]
   },
   "main": "dist/factoria.min.js",
@@ -34,31 +35,32 @@
     "dummy",
     "schema"
   ],
-  "dependencies": {
-    "@babel/polyfill": "^7.4.4"
-  },
   "peerDepedencies": {
     "faker": "^4.1.0"
   },
   "devDependencies": {
-    "@babel/cli": "7.8.4",
-    "@babel/core": "7.8.4",
-    "@babel/preset-env": "7.8.4",
-    "@babel/preset-flow": "7.8.3",
-    "babel-eslint": "8.2.6",
-    "eslint": "4.19.1",
-    "eslint-config-standard": "11.0.0",
-    "eslint-plugin-flowtype": "2.50.3",
-    "eslint-plugin-import": "2.20.1",
-    "eslint-plugin-jest": "21.27.2",
-    "eslint-plugin-node": "6.0.1",
-    "eslint-plugin-promise": "3.8.0",
-    "eslint-plugin-standard": "3.1.0",
+    "@babel/cli": "^7.8.4",
+    "@babel/core": "^7.9.6",
+    "@babel/preset-env": "^7.9.6",
+    "@babel/preset-typescript": "^7.9.0",
+    "@rollup/plugin-typescript": "^4.1.1",
+    "@types/faker": "^4.1.11",
+    "@types/jest": "^25.2.1",
+    "@typescript-eslint/eslint-plugin": "^2.30.0",
+    "@typescript-eslint/parser": "^2.30.0",
+    "eslint": "^6.8.0",
+    "eslint-config-standard": "^14.1.1",
+    "eslint-plugin-import": "^2.20.2",
+    "eslint-plugin-jest": "^23.8.2",
+    "eslint-plugin-node": "^11.1.0",
+    "eslint-plugin-promise": "^4.2.1",
+    "eslint-plugin-standard": "^4.0.1",
     "faker": "4.1.0",
-    "flow-bin": "0.66.0",
     "jest": "24.9.0",
     "rollup": "1.31.1",
     "rollup-plugin-babel": "4.3.3",
-    "rollup-plugin-uglify": "6.0.4"
+    "rollup-plugin-uglify": "6.0.4",
+    "tslib": "^1.11.1",
+    "typescript": "^3.8.3"
   }
 }

rollup.config.js

@@ -1,13 +1,17 @@
 import { uglify } from 'rollup-plugin-uglify'
+import typescript from '@rollup/plugin-typescript'
 import babel from 'rollup-plugin-babel'
 
 export default {
-  input: 'index.js',
+  input: 'index.ts',
+  context: 'this',
+  external: ['faker'],
   output: {
     file: 'dist/factoria.min.js',
     format: 'cjs'
   },
   plugins: [
+    typescript(),
     uglify(),
     babel({
       exclude: 'node_modules/**'

test/index.spec.ts

@@ -0,0 +1,38 @@
+import factory from '..'
+
+const keys = <O extends Object>(obj: O): Array<keyof O> => {
+  return Object.keys(obj) as Array<keyof O>
+}
+
+const validate = (user: Model, overrides = {}): void => {
+  ['id', 'email', 'name'].forEach(key => expect(Object.prototype.hasOwnProperty.call(user, key)).toBe(true))
+  keys(overrides).forEach(key => expect(user[key]).toBe(overrides[key]))
+}
+
+describe('factoria', (): void => {
+  it('generates a model with name', (): void => validate(factory('user')))
+
+  it("overrides a model's properties", () => {
+    validate(factory('user', { email: 'foo@bar.net' }), { email: 'foo@bar.net' })
+  })
+
+  it('generates several models', (): void => {
+    const users = factory('user', 2) as Model[]
+    expect(users).toHaveLength(2)
+    users.forEach(validate)
+  })
+
+  it("overrides multiple models' properties", (): void => {
+    const users = factory('user', 3, { email: 'foo@bar.net' }) as Model[]
+    expect(users).toHaveLength(3)
+    users.forEach(user => validate(user, { email: 'foo@bar.net' }))
+  })
+
+  it('supports define chaining', (): void => {
+    expect(factory.define('foo', faker => ({}))).toEqual(factory)
+  })
+
+  it('supports functions as property overrides', (): void => {
+    validate(factory('user', { email: () => 'foo@bar.net' }), { email: 'foo@bar.net' })
+  })
+})

test/setup.js → test/setup.ts

@@ -1,6 +1,6 @@
 import factory from '..'
 
-factory.define('user', faker => ({
+factory.define('user', (faker: Faker.FakerStatic): Object => ({
   id: faker.random.number(),
   name: faker.name.findName(),
   email: faker.internet.email()

tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "target": "es5",
+    "strict": true,
+    "module": "es2015",
+    "moduleResolution": "node",
+    "allowSyntheticDefaultImports": true,
+    "noImplicitThis": false,
+    "downlevelIteration": true
+  },
+  "include": [
+    "index.ts",
+    "test/**/*.ts"
+  ]
+}