Require Node.js 12 and move to ESM

.github/workflows/main.yml

@@ -12,15 +12,15 @@ jobs:
         node-version:
           - 14
           - 12
-          - 10
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install
       - run: npm test
-      - uses: codecov/codecov-action@v1
-        if: matrix.node-version == 14
-        with:
-          fail_ci_if_error: true
+      # TODO: Disabled until `nyc` supports ESM.
+      # - uses: codecov/codecov-action@v1
+      #   if: matrix.node-version == 14
+      #   with:
+      #     fail_ci_if_error: true

index.d.ts

@@ -1,32 +1,30 @@
-declare namespace QuickLRU {
-	interface Options<KeyType, ValueType> {
-		/**
-		The maximum number of milliseconds an item should remain in the cache.
+export interface Options<KeyType, ValueType> {
+	/**
+	The maximum number of milliseconds an item should remain in the cache.
 
-		@default Infinity
+	@default Infinity
 
-		By default, `maxAge` will be `Infinity`, which means that items will never expire.
-		Lazy expiration upon the next write or read call.
+	By default, `maxAge` will be `Infinity`, which means that items will never expire.
+	Lazy expiration upon the next write or read call.
 
-		Individual expiration of an item can be specified by the `set(key, value, maxAge)` method.
-		*/
-		readonly maxAge?: number;
+	Individual expiration of an item can be specified by the `set(key, value, maxAge)` method.
+	*/
+	readonly maxAge?: number;
 
-		/**
-		The maximum number of items before evicting the least recently used items.
-		*/
-		readonly maxSize: number;
+	/**
+	The maximum number of items before evicting the least recently used items.
+	*/
+	readonly maxSize: number;
 
-		/**
-		Called right before an item is evicted from the cache.
+	/**
+	Called right before an item is evicted from the cache.
 
-		Useful for side effects or for items like object URLs that need explicit cleanup (`revokeObjectURL`).
-		*/
-		onEviction?: (key: KeyType, value: ValueType) => void;
-	}
+	Useful for side effects or for items like object URLs that need explicit cleanup (`revokeObjectURL`).
+	*/
+	onEviction?: (key: KeyType, value: ValueType) => void;
 }
 
-declare class QuickLRU<KeyType, ValueType> implements Iterable<[KeyType, ValueType]> {
+export default class QuickLRU<KeyType, ValueType> implements Iterable<[KeyType, ValueType]> {
 	/**
 	The stored item count.
 	*/
@@ -39,7 +37,7 @@ declare class QuickLRU<KeyType, ValueType> implements Iterable<[KeyType, ValueTy
 
 	@example
 	```
-	import QuickLRU = require('quick-lru');
+	import QuickLRU from 'quick-lru';
 
 	const lru = new QuickLRU({maxSize: 1000});
 
@@ -52,7 +50,7 @@ declare class QuickLRU<KeyType, ValueType> implements Iterable<[KeyType, ValueTy
 	//=> '🌈'
 	```
 	*/
-	constructor(options: QuickLRU.Options<KeyType, ValueType>);
+	constructor(options: Options<KeyType, ValueType>);
 
 	[Symbol.iterator](): IterableIterator<[KeyType, ValueType]>;
 
@@ -123,5 +121,3 @@ declare class QuickLRU<KeyType, ValueType> implements Iterable<[KeyType, ValueTy
 	*/
 	entriesDescending(): IterableIterator<[KeyType, ValueType]>;
 }
-
-export = QuickLRU;

index.js

@@ -1,6 +1,4 @@
-'use strict';
-
-class QuickLRU {
+export default class QuickLRU {
 	constructor(options = {}) {
 		if (!(options.maxSize && options.maxSize > 0)) {
 			throw new TypeError('`maxSize` must be a number greater than 0');
@@ -10,14 +8,16 @@ class QuickLRU {
 			throw new TypeError('`maxAge` must be a number greater than 0');
 		}
 
+		// TODO: Use private class fields when ESLint supports them.
 		this.maxSize = options.maxSize;
-		this.maxAge = options.maxAge || Infinity;
+		this.maxAge = options.maxAge || Number.POSITIVE_INFINITY;
 		this.onEviction = options.onEviction;
 		this.cache = new Map();
 		this.oldCache = new Map();
 		this._size = 0;
 	}
 
+	// TODO: Use private class methods when targeting Node.js 16.
 	_emitEvictions(cache) {
 		if (typeof this.onEviction !== 'function') {
 			return;
@@ -110,7 +110,7 @@ class QuickLRU {
 		}
 	}
 
-	set(key, value, {maxAge = this.maxAge === Infinity ? undefined : Date.now() + this.maxAge} = {}) {
+	set(key, value, {maxAge = this.maxAge === Number.POSITIVE_INFINITY ? undefined : Date.now() + this.maxAge} = {}) {
 		if (this.cache.has(key)) {
 			this.cache.set(key, {
 				value,
@@ -259,5 +259,3 @@ class QuickLRU {
 		return Math.min(this._size + oldCacheSize, this.maxSize);
 	}
 }
-
-module.exports = QuickLRU;

index.test-d.ts

@@ -1,5 +1,5 @@
 import {expectType} from 'tsd';
-import QuickLRU = require('.');
+import QuickLRU from './index.js';
 
 const lru = new QuickLRU<string, number>({maxSize: 1000, maxAge: 200});
 
@@ -8,7 +8,6 @@ expectType<number | undefined>(lru.get('🦄'));
 expectType<boolean>(lru.has('🦄'));
 expectType<number | undefined>(lru.peek('🦄'));
 expectType<boolean>(lru.delete('🦄'));
-expectType<void>(lru.clear());
 expectType<number>(lru.size);
 
 for (const [key, value] of lru) {

package.json

@@ -10,11 +10,14 @@
 		"email": "[email protected]",
 		"url": "https://sindresorhus.com"
 	},
+	"type": "module",
+	"exports": "./index.js",
 	"engines": {
-		"node": ">=10"
+		"node": ">=12"
 	},
 	"scripts": {
-		"test": "xo && nyc ava && tsd"
+		"//test": "xo && nyc ava && tsd",
+		"test": "xo && ava && tsd"
 	},
 	"files": [
 		"index.js",
@@ -34,10 +37,10 @@
 		"buffer"
 	],
 	"devDependencies": {
-		"ava": "^2.4.0",
+		"ava": "^3.15.0",
 		"nyc": "^15.1.0",
-		"tsd": "^0.13.1",
-		"xo": "^0.35.0"
+		"tsd": "^0.14.0",
+		"xo": "^0.37.1"
 	},
 	"nyc": {
 		"reporter": [

readme.md

@@ -15,7 +15,7 @@ $ npm install quick-lru
 ## Usage
 
 ```js
-const QuickLRU = require('quick-lru');
+import QuickLRU from 'quick-lru';
 
 const lru = new QuickLRU({maxSize: 1000});