snapshot of https://github.com/RocketChat/Rocket.Chat.git (develop, 2026-09-16; blobs > 131072B omitted)

packages/memo/jest.config.ts

@@ -0,0 +1,6 @@
+import server from '@rocket.chat/jest-presets/server';
+import type { Config } from 'jest';
+
+export default {
+	preset: server.preset,
+} satisfies Config;

packages/memo/package.json

@@ -0,0 +1,46 @@
+{
+	"name": "@rocket.chat/memo",
+	"version": "0.31.25",
+	"description": "Memoization utilities",
+	"keywords": [
+		"memoize"
+	],
+	"bugs": {
+		"url": "https://github.com/RocketChat/Rocket.Chat/issues"
+	},
+	"repository": {
+		"type": "git",
+		"url": "git+https://github.com/RocketChat/Rocket.Chat.git",
+		"directory": "packages/memo"
+	},
+	"license": "MIT",
+	"author": {
+		"name": "Rocket.Chat",
+		"url": "https://rocket.chat/"
+	},
+	"main": "dist/cjs/index.js",
+	"module": "dist/esm/index.js",
+	"types": "dist/esm/index.d.ts",
+	"files": [
+		"/dist"
+	],
+	"scripts": {
+		"build": "rm -rf dist && tsc -p tsconfig.cjs.json && tsc -p tsconfig.esm.json",
+		"lint": "eslint .",
+		"lint:fix": "eslint --fix .",
+		"test": "jest",
+		"testunit": "jest",
+		"typecheck": "tsc --noEmit"
+	},
+	"devDependencies": {
+		"@rocket.chat/jest-presets": "workspace:~",
+		"@rocket.chat/tsconfig": "workspace:~",
+		"eslint": "~9.39.5",
+		"jest": "~30.2.0",
+		"ts-jest": "~29.4.12",
+		"typescript": "~5.9.3"
+	},
+	"volta": {
+		"extends": "../../package.json"
+	}
+}

packages/memo/src/index.ts

@@ -0,0 +1 @@
+export { memoize, clear, type MemoizableFunction, type MemoizedFunction, type Options } from './memoize';

packages/memo/src/memoize.spec.ts

@@ -0,0 +1,105 @@
+import { memoize, clear } from './memoize';
+
+it('should memoize a function that takes no parameter', () => {
+	const fn = jest.fn(() => 'foo');
+	const memoized = jest.fn(memoize(fn));
+
+	memoized(undefined);
+	memoized(undefined);
+
+	expect(memoized).toHaveBeenCalledTimes(2);
+	expect(fn).toHaveBeenCalledTimes(1);
+
+	expect(fn).toHaveReturnedWith('foo');
+	expect(memoized).toHaveReturnedWith('foo');
+});
+
+it('should memoize a function that takes one parameter', () => {
+	const fn = jest.fn((i: number) => i + 1);
+	const memoized = jest.fn(memoize(fn));
+
+	memoized(5);
+	memoized(5);
+	memoized(2);
+
+	expect(memoized).toHaveBeenCalledTimes(3);
+	expect(fn).toHaveBeenCalledTimes(2);
+
+	expect(fn).toHaveNthReturnedWith(1, 6);
+	expect(fn).toHaveNthReturnedWith(2, 3);
+
+	expect(memoized).toHaveNthReturnedWith(1, 6);
+	expect(memoized).toHaveNthReturnedWith(2, 6);
+	expect(memoized).toHaveNthReturnedWith(3, 3);
+});
+
+describe('clear', () => {
+	it('should discard cached values of a memoized function', () => {
+		const fn = jest.fn(() => 'foo');
+		const memoized = memoize(fn);
+		const spiedMemoized = jest.fn(memoized);
+
+		spiedMemoized(undefined);
+		spiedMemoized(undefined);
+		clear(memoized);
+		spiedMemoized(undefined);
+
+		expect(spiedMemoized).toHaveBeenCalledTimes(3);
+		expect(fn).toHaveBeenCalledTimes(2);
+
+		expect(fn).toHaveReturnedWith('foo');
+		expect(spiedMemoized).toHaveReturnedWith('foo');
+	});
+
+	it('should do nothing when a non-memoized function is passed', () => {
+		const fn = jest.fn(() => 'foo');
+
+		expect(() => clear(fn)).not.toThrow();
+	});
+});
+
+describe('timeout', () => {
+	it('should memoize a function that takes one parameter and clear after x ms', () => {
+		jest.useFakeTimers();
+
+		const fn = jest.fn((i: number) => i + 1);
+		const memoized = jest.fn(memoize(fn, { maxAge: 3000 }));
+
+		memoized(5);
+		jest.advanceTimersByTime(2000);
+		memoized(5);
+		jest.advanceTimersByTime(2000);
+		memoized(5);
+		jest.advanceTimersByTime(3000);
+		memoized(5);
+
+		expect(fn).toHaveBeenCalledTimes(2);
+
+		expect(memoized).toHaveNthReturnedWith(1, 6);
+		expect(memoized).toHaveNthReturnedWith(2, 6);
+		expect(memoized).toHaveNthReturnedWith(3, 6);
+		expect(memoized).toHaveNthReturnedWith(4, 6);
+	});
+
+	it('should memoize a function caching for two parameters and clearing both after x ms each one', () => {
+		jest.useFakeTimers();
+
+		const fn = jest.fn((i: number) => i + 1);
+		const memoized = jest.fn(memoize(fn, { maxAge: 3000 }));
+
+		memoized(5);
+		jest.advanceTimersByTime(2000);
+		memoized(6);
+		jest.advanceTimersByTime(2000);
+
+		memoized(6);
+		memoized(5);
+
+		expect(fn).toHaveBeenCalledTimes(3);
+
+		expect(memoized).toHaveNthReturnedWith(1, 6);
+		expect(memoized).toHaveNthReturnedWith(2, 7);
+		expect(memoized).toHaveNthReturnedWith(3, 7);
+		expect(memoized).toHaveNthReturnedWith(4, 6);
+	});
+});

packages/memo/src/memoize.ts

@@ -0,0 +1,59 @@
+export type MemoizableFunction<T, A, R> = (this: T, arg: A) => R;
+export type MemoizedFunction<T, A, R> = (this: T, arg: A) => R;
+
+export type Options = {
+	maxAge: number;
+};
+
+const store = new WeakMap<MemoizableFunction<unknown, unknown, unknown>, Map<unknown, unknown>>();
+
+const isCachedValue = <A, R>(cachedValue: R | undefined, arg: A, cache: Map<A, R>): cachedValue is R =>
+	cache.has(arg) && cache.get(arg) === cachedValue;
+
+export const memoize = <T, A, R>(fn: MemoizableFunction<T, A, R>, _options?: Options): MemoizedFunction<T, A, R> => {
+	const cache = new Map<A, R>();
+	const cacheTimers = new Map<A, ReturnType<typeof setTimeout>>();
+
+	const memoized: MemoizedFunction<T, A, R> = function (this, arg) {
+		const cleanUp = (): void => {
+			cache.delete(arg);
+			cacheTimers.delete(arg);
+		};
+
+		const cachedValue = cache.get(arg);
+
+		if (isCachedValue(cachedValue, arg, cache)) {
+			const oldTimer = cacheTimers.get(arg);
+			if (oldTimer) {
+				clearTimeout(oldTimer);
+			}
+
+			if (_options) {
+				const timer = setTimeout(cleanUp, _options.maxAge);
+				cacheTimers.set(arg, timer);
+			}
+
+			return cachedValue;
+		}
+
+		const result = fn.call(this, arg);
+
+		cache.set(arg, result);
+
+		if (_options) {
+			const timer = setTimeout(cleanUp, _options.maxAge);
+			cacheTimers.set(arg, timer);
+		}
+
+		return result;
+	};
+
+	store.set(memoized as MemoizableFunction<unknown, unknown, unknown>, cache);
+
+	return memoized;
+};
+
+export const clear = (fn: MemoizedFunction<unknown, unknown, unknown>): void => {
+	const cache = store.get(fn);
+	cache?.clear();
+};

packages/memo/tsconfig.cjs.json

@@ -0,0 +1,12 @@
+{
+	"extends": "./tsconfig.json",
+	"compilerOptions": {
+		"module": "commonjs",
+		"moduleResolution": "node",
+		"declaration": true,
+		"declarationMap": true,
+		"sourceMap": true,
+		"outDir": "./dist/cjs"
+	},
+	"exclude": ["**/*.spec.*", "jest.config.*"]
+}

packages/memo/tsconfig.esm.json

@@ -0,0 +1,12 @@
+{
+	"extends": "./tsconfig.json",
+	"compilerOptions": {
+		"module": "esnext",
+		"moduleResolution": "node",
+		"declaration": true,
+		"declarationMap": true,
+		"sourceMap": true,
+		"outDir": "./dist/esm"
+	},
+	"exclude": ["**/*.spec.*", "jest.config.*"]
+}

packages/memo/tsconfig.json

@@ -0,0 +1,4 @@
+{
+	"extends": "@rocket.chat/tsconfig/base.json",
+	"include": ["src/**/*"]
+}