Use tsconfig.json & make sure common types are included in packed build

common.d.ts

@@ -0,0 +1,2 @@
+declare type ValueOf<T> = T[keyof T]
+declare type PlainObject<T = any> = { [key: string]: T }

package.json

@@ -2,7 +2,8 @@
   "name": "@mrolaolu/helpers",
   "license": "MIT",
   "files": [
-    "dist"
+    "dist",
+    "common.d.ts"
   ],
   "version": "0.3.0",
   "main": "dist/cjs/index.js",

rollup.config.js

@@ -1,5 +1,6 @@
 import path from 'path'
 import babel from 'rollup-plugin-babel'
+import defaultTsConfig from './tsconfig.json'
 import multiInput from 'rollup-plugin-multi-input'
 import typescript from '@rollup/plugin-typescript'
 
@@ -10,16 +11,11 @@ export default {
   plugins: [
     multiInput(),
     typescript({
-      lib: ['DOM'],
-      target: 'es5',
-      downlevelIteration: true,
-      outDir: isCommonJS ? 'dist/cjs' : 'dist/esm',
-      strict: true,
-      rootDir: 'src',
-      pretty: true,
-      declaration: true,
-      esModuleInterop: true,
-      exclude: ['node_modules', 'dist'],
+      ...defaultTsConfig.compilerOptions,
+      ...{
+        outDir: isCommonJS ? 'dist/cjs' : 'dist/esm',
+        exclude: defaultTsConfig.exclude,
+      },
     }),
     babel({
       exclude: 'node_modules/**',

tsconfig.json

@@ -0,0 +1,13 @@
+{
+  "compilerOptions": {
+    "lib": ["DOM"],
+    "target": "es5",
+    "downlevelIteration": true,
+    "strict": true,
+    "rootDir": "src",
+    "pretty": true,
+    "declaration": true,
+    "esModuleInterop": true
+  },
+  "exclude": ["node_modules", "dist"]
+}