Automatically release memory when an item expires - fixes #14

index.js

@@ -1,6 +1,7 @@
 'use strict';
 const mimicFn = require('mimic-fn');
 const isPromise = require('p-is-promise');
+const mapAgeCleaner = require('map-age-cleaner');
 
 const cacheStore = new WeakMap();
 
@@ -26,18 +27,18 @@ module.exports = (fn, options) => {
 		cachePromiseRejection: false
 	}, options);
 
+	if (typeof options.maxAge === 'number') {
+		mapAgeCleaner(options.cache);
+	}
+
 	const memoized = function (...args) {
 		const cache = cacheStore.get(memoized);
 		const key = options.cacheKey(...args);
 
 		if (cache.has(key)) {
 			const c = cache.get(key);
 
-			if (typeof options.maxAge !== 'number' || Date.now() < c.maxAge) {
-				return c.data;
-			}
-
-			cache.delete(key);
+			return c.data;
 		}
 
 		const ret = fn.call(this, ...args);

package.json

@@ -32,6 +32,7 @@
 		"promise"
 	],
 	"dependencies": {
+		"map-age-cleaner": "^0.1.1",
 		"mimic-fn": "^1.0.0",
 		"p-is-promise": "^1.1.0"
 	},

readme.md

@@ -2,6 +2,8 @@
 
 > [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
 
+Memory is automatically released when an item expires.
+
 
 ## Install
 

test.js

@@ -45,7 +45,11 @@ test('maxAge option deletes old items', async t => {
 	const f = () => i++;
 	const cache = new Map();
 	const deleted = [];
-	cache.delete = item => deleted.push(item);
+	const remove = cache.delete.bind(cache);
+	cache.delete = item => {
+		deleted.push(item);
+		return remove(item);
+	};
 	const memoized = m(f, {maxAge: 100, cache});
 	t.is(memoized(1), 0);
 	t.is(memoized(1), 0);