fix: improve replacer type definition

The replacer type may return an object while still guaranteeing that
the overall return type is string.

Change the tsconfig moduleResolution to nodenext to properly test
the esm type definition.

Author: BridgeAR

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## v2.4.2
+
+- Improved ESM TypeScript types.
+- More precise TypeScript replacer type.
+
 ## v2.4.1
 
 - More precise TypeScript types. The return type is now either `string`, `undefined` or `string | undefined` depending on the input.

esm/wrapper.d.ts

@@ -1,4 +1,4 @@
-import { stringify } from '../index.js';
+import { stringify } from '../index.js'
 
-export * from '../index.js';
-export default stringify;
+export * from '../index.js'
+export default stringify

index.d.ts

@@ -1,4 +1,4 @@
-export type Replacer =  (number | string)[] | null | undefined | ((key: string, value: unknown) => string | number | boolean | null)
+export type Replacer = (number | string)[] | null | undefined | ((key: string, value: unknown) => string | number | boolean | null | object)
 
 export function stringify(value: undefined | symbol | ((...args: unknown[]) => unknown), replacer?: Replacer, space?: string | number): undefined
 export function stringify(value: string | number | unknown[] | null | boolean | object, replacer?: Replacer, space?: string | number): string

package.json

@@ -39,7 +39,7 @@
   "typings": "index.d.ts",
   "devDependencies": {
     "@types/json-stable-stringify": "^1.0.34",
-    "@types/node": "^16.11.1",
+    "@types/node": "^18.11.18",
     "benchmark": "^2.1.4",
     "clone": "^2.1.2",
     "fast-json-stable-stringify": "^2.1.0",

test.js

@@ -279,7 +279,8 @@ test('invalid replacer being ignored', function (assert) {
 
   // @ts-expect-error
   const actual = stringify(obj, 'invalidReplacer')
-  const expected = stringify(obj)
+  // @ts-expect-error
+  const expected = stringify(obj, 'invalidReplacer')
   assert.equal(actual, expected)
 
   assert.end()

tsconfig.json

@@ -8,7 +8,7 @@
     "noEmit": true,
     "downlevelIteration": false,
     "experimentalDecorators": false,
-    "moduleResolution": "node",
+    "moduleResolution": "nodenext",
     "importHelpers": false,
     "target": "esnext",
     "module": "CommonJS",