build(typescript): add typescript and setup the build to build with t…

…ypescript

.gitignore

@@ -1,2 +1,3 @@
 node_modules
 dist/*
+types/*

package.json

@@ -26,15 +26,17 @@
     "readme.md"
   ],
   "scripts": {
-    "build": "rollup -c",
+    "build": "rollup -c && npm run typedef",
     "size": "npm run build && terser --compress --mangle -- ./dist/umd.js | gzip -c | wc -c",
     "test": "npm run build && tape test/*.js && jsmd readme.md && npm run test:typescript",
-    "test:typescript": "tsc --noEmit test/typescript.ts && ts-node test/typescript.ts"
+    "test:typescript": "tsc --noEmit test/typescript.ts && ts-node test/typescript.ts",
+    "typedef": "tsc -p tsconfig.typedef.json"
   },
   "dependencies": {},
   "devDependencies": {
     "@rollup/plugin-commonjs": "^16.0.0",
     "@rollup/plugin-node-resolve": "^10.0.0",
+    "@rollup/plugin-typescript": "^6.1.0",
     "@types/node": "^8.10.54",
     "is-mergeable-object": "1.1.0",
     "is-plain-obj": "^3.0.0",
@@ -43,7 +45,8 @@
     "tape": "^5.0.1",
     "terser": "^5.3.8",
     "ts-node": "^9.0.0",
-    "typescript": "=2.2.2"
+    "tslib": "^2.0.3",
+    "typescript": "^4.1.1-rc"
   },
   "engines": {
     "node": ">=0.10.0"

rollup.config.js

@@ -2,13 +2,15 @@
 
 import resolve from '@rollup/plugin-node-resolve'
 import commonjs from '@rollup/plugin-commonjs'
+import typescript from '@rollup/plugin-typescript';
 import pkg from './package.json'
 
 export default {
-	input: `src/index.js`,
+	input: `src/index.ts`,
 	plugins: [
-		commonjs(),
 		resolve(),
+		commonjs(),
+		typescript()
 	],
 	output: [
 		{

src/index.js → src/index.ts

@@ -1,4 +1,5 @@
-var isPlainObj = require('is-plain-obj')
+import isPlainObj from 'is-plain-obj';
+
 function defaultIsMergeable(value) {
 	return Array.isArray(value) || isPlainObj(value)
 }
@@ -75,7 +76,7 @@ function mergeObject(target, source, options) {
 	return destination
 }
 
-function deepmerge(target, source, options) {
+export default function deepmerge(target, source, options) {
 	options = Object.assign({
 		arrayMerge: defaultArrayMerge,
 		isMergeable: defaultIsMergeable
@@ -96,7 +97,7 @@ function deepmerge(target, source, options) {
 	}
 }
 
-deepmerge.all = function deepmergeAll(array, options) {
+export function deepmergeAll(array, options) {
 	if (!Array.isArray(array)) {
 		throw new Error('first argument should be an array')
 	}
@@ -105,5 +106,3 @@ deepmerge.all = function deepmergeAll(array, options) {
 		return deepmerge(prev, next, options)
 	}, {})
 }
-
-module.exports = deepmerge

tsconfig.json

@@ -0,0 +1,17 @@
+{
+	"compilerOptions": {
+		"target": "ES2020",
+		"module": "ES2020",
+		"lib": [
+			"ES2020"
+		],
+		"moduleResolution": "node",
+		"esModuleInterop": true,
+		"strict": true,
+		"skipLibCheck": true,
+		"forceConsistentCasingInFileNames": true
+	},
+	"include": [
+		"src"
+	]
+}

tsconfig.typedef.json

@@ -0,0 +1,8 @@
+{
+	"extends": "./tsconfig.json",
+	"compilerOptions": {
+		"declaration": true,
+		"declarationDir": "types/",
+		"emitDeclarationOnly": true
+	}
+}