Require Node.js 18

.github/funding.yml

@@ -1,2 +1 @@
 github: [sindresorhus, fregante]
-tidelift: npm/mem

.github/workflows/main.yml

@@ -12,10 +12,9 @@ jobs:
         node-version:
           #- 20
           - 18
-          - 16
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-node@v3
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install

index.ts

@@ -1,7 +1,7 @@
-import mimicFn from 'mimic-fn';
+import mimicFunction from 'mimic-function';
 import mapAgeCleaner from 'map-age-cleaner';
 
-type AnyFunction = (...arguments_: any) => any;
+type AnyFunction = (...arguments_: readonly any[]) => any;
 
 const cacheStore = new WeakMap<AnyFunction, CacheStorage<any, any>>();
 
@@ -68,7 +68,7 @@ export type Options<
 /**
 [Memoize](https://en.wikipedia.org/wiki/Memoization) functions - An optimization used to speed up consecutive function calls by caching the result of calls with identical input.
 
-@param fn - Function to be memoized.
+@param fn - The function to be memoized.
 
 @example
 ```
@@ -113,7 +113,7 @@ export default function mem<
 
 		const cacheItem = cache.get(key);
 		if (cacheItem) {
-			return cacheItem.data; // eslint-disable-line @typescript-eslint/no-unsafe-return
+			return cacheItem.data;
 		}
 
 		const result = fn.apply(this, arguments_) as ReturnType<FunctionToMemoize>;
@@ -123,10 +123,10 @@ export default function mem<
 			maxAge: maxAge ? Date.now() + maxAge : Number.POSITIVE_INFINITY,
 		});
 
-		return result; // eslint-disable-line @typescript-eslint/no-unsafe-return
+		return result;
 	} as FunctionToMemoize;
 
-	mimicFn(memoized, fn, {
+	mimicFunction(memoized, fn, {
 		ignoreNonConfigurable: true,
 	});
 

package.json

@@ -11,16 +11,19 @@
 		"url": "https://sindresorhus.com"
 	},
 	"type": "module",
-	"exports": "./dist/index.js",
+	"exports": {
+		"types": "./dist/index.d.ts",
+		"default": "./dist/index.js"
+	},
+	"sideEffects": false,
 	"engines": {
-		"node": ">=16"
+		"node": ">=18"
 	},
 	"scripts": {
-		"test": "xo && ava && npm run build && tsd",
+		"test": "xo && ava && npm run build && tsd --typings dist/index.d.ts",
 		"build": "del-cli dist && tsc",
 		"prepack": "npm run build"
 	},
-	"types": "dist/index.d.ts",
 	"files": [
 		"dist"
 	],
@@ -39,19 +42,18 @@
 	],
 	"dependencies": {
 		"map-age-cleaner": "^0.2.0",
-		"mimic-fn": "^4.0.0"
+		"mimic-function": "^5.0.0"
 	},
 	"devDependencies": {
-		"@sindresorhus/tsconfig": "^3.0.1",
-		"@types/serialize-javascript": "^5.0.2",
-		"ava": "^5.2.0",
-		"del-cli": "^5.0.0",
-		"delay": "^5.0.0",
+		"@sindresorhus/tsconfig": "^5.0.0",
+		"@types/serialize-javascript": "^5.0.4",
+		"ava": "^5.3.1",
+		"del-cli": "^5.1.0",
+		"delay": "^6.0.0",
 		"serialize-javascript": "^6.0.1",
 		"ts-node": "^10.9.1",
-		"tsd": "^0.28.1",
-		"typescript": "^5.0.4",
-		"xo": "^0.54.2"
+		"tsd": "^0.29.0",
+		"xo": "^0.56.0"
 	},
 	"ava": {
 		"timeout": "1m",
@@ -64,9 +66,7 @@
 	},
 	"xo": {
 		"rules": {
-			"@typescript-eslint/member-ordering": "off",
-			"@typescript-eslint/no-var-requires": "off",
-			"@typescript-eslint/no-empty-function": "off"
+			"@typescript-eslint/no-unsafe-return": "off"
 		}
 	}
 }

readme.md

@@ -12,8 +12,8 @@ If you want to memoize Promise-returning functions (like `async` functions), you
 
 ## Install
 
-```
-$ npm install mem
+```sh
+npm install mem
 ```
 
 ## Usage
@@ -164,7 +164,7 @@ Better yet, if your function’s arguments are compatible with `WeakMap`, you sh
 
 Type: `Function`
 
-Function to be memoized.
+The function to be memoized.
 
 #### options
 
@@ -273,15 +273,3 @@ console.log(cache.stats);
 ## Related
 
 - [p-memoize](https://github.com/sindresorhus/p-memoize) - Memoize promise-returning & async functions
-
----
-
-<div align="center">
-	<b>
-		<a href="https://tidelift.com/subscription/pkg/npm-mem?utm_source=npm-mem&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a>
-	</b>
-	<br>
-	<sub>
-		Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies.
-	</sub>
-</div>

test.ts

@@ -162,7 +162,7 @@ test('promise support', async t => {
 });
 
 test('preserves the original function name', t => {
-	t.is(mem(function foo() {}).name, 'foo'); // eslint-disable-line func-names
+	t.is(mem(function foo() {}).name, 'foo'); // eslint-disable-line func-names, @typescript-eslint/no-empty-function
 });
 
 test('.clear()', t => {
@@ -220,7 +220,7 @@ test('.decorator()', t => {
 
 test('memClear() throws when called with a plain function', t => {
 	t.throws(() => {
-		memClear(() => {});
+		memClear(() => {}); // eslint-disable-line @typescript-eslint/no-empty-function
 	}, {
 		message: 'Can\'t clear a function that was not memoized!',
 		instanceOf: TypeError,