Require Node.js 8, add TypeScript definition (#11)

.travis.yml

@@ -2,6 +2,5 @@ language: node_js
 node_js:
   - '10'
   - '8'
-  - '6'
 after_success:
   - './node_modules/.bin/nyc report --reporter=text-lcov | ./node_modules/.bin/coveralls'

index.d.ts

@@ -0,0 +1,73 @@
+export interface Options {
+	/**
+	 * The maximum number of items before evicting the least recently used items.
+	 */
+	readonly maxSize: number;
+}
+
+declare class QuickLRU<KeyType extends unknown, ValueType extends unknown>
+	implements Iterable<[KeyType, ValueType]> {
+	/**
+	 * The stored item count.
+	 */
+	readonly size: number;
+
+	/**
+	 * Simple ["Least Recently Used" (LRU) cache](https://en.m.wikipedia.org/wiki/Cache_replacement_policies#Least_Recently_Used_.28LRU.29).
+	 *
+	 * The instance is [`iterable`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Iteration_protocols) so you can use it directly in a [`for…of`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Statements/for...of) loop.
+	 */
+	constructor(options: Options);
+
+	[Symbol.iterator](): IterableIterator<[KeyType, ValueType]>;
+
+	/**
+	 * Set an item.
+	 *
+	 * @returns The list instance.
+	 */
+	set(key: KeyType, value: ValueType): this;
+
+	/**
+	 * Get an item.
+	 *
+	 * @returns The stored item or `undefined`.
+	 */
+	get(key: KeyType): ValueType | undefined;
+
+	/**
+	 * Check if an item exists.
+	 */
+	has(key: KeyType): boolean;
+
+	/**
+	 * Get an item without marking it as recently used.
+	 *
+	 * @returns The stored item or `undefined`.
+	 */
+	peek(key: KeyType): ValueType | undefined;
+
+	/**
+	 * Delete an item.
+	 *
+	 * @returns `true` if the item is removed or `false` if the item doesn't exist.
+	 */
+	delete(key: KeyType): boolean;
+
+	/**
+	 * Delete all items.
+	 */
+	clear(): void;
+
+	/**
+	 * Iterable for all the keys.
+	 */
+	keys(): IterableIterator<KeyType>;
+
+	/**
+	 * Iterable for all the values.
+	 */
+	values(): IterableIterator<ValueType>;
+}
+
+export default QuickLRU;

index.js

@@ -112,3 +112,4 @@ class QuickLRU {
 }
 
 module.exports = QuickLRU;
+module.exports.default = QuickLRU;

index.test-d.ts

@@ -0,0 +1,25 @@
+import {expectType} from 'tsd-check';
+import QuickLRU from '.';
+
+const lru = new QuickLRU<string, number>({maxSize: 1000});
+
+expectType<QuickLRU<string, number>>(lru.set('🦄', 1).set('🌈', 2));
+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) {
+	expectType<string>(key);
+	expectType<number>(value);
+}
+
+for (const key of lru.keys()) {
+	expectType<string>(key);
+}
+
+for (const value of lru.values()) {
+	expectType<number>(value);
+}

package.json

@@ -10,13 +10,14 @@
 		"url": "sindresorhus.com"
 	},
 	"engines": {
-		"node": ">=6"
+		"node": ">=8"
 	},
 	"scripts": {
-		"test": "xo && nyc ava"
+		"test": "xo && nyc ava && tsd-check"
 	},
 	"files": [
-		"index.js"
+		"index.js",
+		"index.d.ts"
 	],
 	"keywords": [
 		"lru",
@@ -32,9 +33,10 @@
 		"buffer"
 	],
 	"devDependencies": {
-		"ava": "^0.25.0",
+		"ava": "^1.3.1",
 		"coveralls": "^3.0.1",
 		"nyc": "^13.1.0",
-		"xo": "^0.23.0"
+		"tsd-check": "^0.3.0",
+		"xo": "^0.24.0"
 	}
 }

readme.md

@@ -90,7 +90,7 @@ Iterable for all the values.
 
 #### .size
 
-Get the item count.
+The stored item count.
 
 
 ## License