element-web/test/unit-tests/utils/LruCache-test.ts

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/*
Copyright 2024 New Vector Ltd.
Copyright 2023 The Matrix.org Foundation C.I.C.
SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
Please see LICENSE files in the repository root for full details.
*/
import { logger } from "matrix-js-sdk/src/logger";
import { LruCache } from "../../../src/utils/LruCache";
describe("LruCache", () => {
it("when creating a cache with negative capacity it should raise an error", () => {
expect(() => {
new LruCache(-23);
}).toThrow("Cache capacity must be at least 1");
});
it("when creating a cache with 0 capacity it should raise an error", () => {
expect(() => {
new LruCache(0);
}).toThrow("Cache capacity must be at least 1");
});
describe("when there is a cache with a capacity of 3", () => {
let cache: LruCache<string, string>;
beforeEach(() => {
cache = new LruCache(3);
});
it("has() should return false", () => {
expect(cache.has("a")).toBe(false);
});
it("get() should return undefined", () => {
expect(cache.get("a")).toBeUndefined();
});
it("values() should return an empty iterator", () => {
expect(Array.from(cache.values())).toEqual([]);
});
it("delete() should not raise an error", () => {
cache.delete("a");
});
describe("when the cache contains 2 items", () => {
beforeEach(() => {
cache.set("a", "a value");
cache.set("b", "b value");
});
it("has() should return false for an item not in the cache", () => {
expect(cache.has("c")).toBe(false);
});
it("get() should return undefined for an item not in the cahce", () => {
expect(cache.get("c")).toBeUndefined();
});
it("values() should return the items in the cache", () => {
expect(Array.from(cache.values())).toEqual(["a value", "b value"]);
});
it("clear() should clear the cache", () => {
cache.clear();
expect(cache.has("a")).toBe(false);
expect(cache.has("b")).toBe(false);
expect(Array.from(cache.values())).toEqual([]);
});
it("when an error occurs while setting an item the cache should be cleard", () => {
jest.spyOn(logger, "warn");
const err = new Error("Something weng wrong :(");
// @ts-ignore
cache.safeSet = () => {
throw err;
};
cache.set("c", "c value");
expect(Array.from(cache.values())).toEqual([]);
expect(logger.warn).toHaveBeenCalledWith("LruCache error", err);
});
describe("and adding another item", () => {
beforeEach(() => {
cache.set("c", "c value");
});
it("deleting an unkonwn item should not raise an error", () => {
cache.delete("unknown");
});
it("deleting the first item should work", () => {
cache.delete("a");
expect(Array.from(cache.values())).toEqual(["b value", "c value"]);
// add an item after delete should work work
cache.set("d", "d value");
expect(Array.from(cache.values())).toEqual(["b value", "c value", "d value"]);
});
it("deleting the item in the middle should work", () => {
cache.delete("b");
expect(Array.from(cache.values())).toEqual(["a value", "c value"]);
// add an item after delete should work work
cache.set("d", "d value");
expect(Array.from(cache.values())).toEqual(["a value", "c value", "d value"]);
});
it("deleting the last item should work", () => {
cache.delete("c");
expect(Array.from(cache.values())).toEqual(["a value", "b value"]);
// add an item after delete should work work
cache.set("d", "d value");
expect(Array.from(cache.values())).toEqual(["a value", "b value", "d value"]);
});
it("deleting all items should work", () => {
cache.delete("a");
cache.delete("b");
cache.delete("c");
// should not raise an error
cache.delete("a");
cache.delete("b");
cache.delete("c");
expect(Array.from(cache.values())).toEqual([]);
// add an item after delete should work work
cache.set("d", "d value");
expect(Array.from(cache.values())).toEqual(["d value"]);
});
it("deleting and adding some items should work", () => {
cache.set("d", "d value");
cache.get("b");
cache.delete("b");
cache.set("e", "e value");
expect(Array.from(cache.values())).toEqual(["c value", "d value", "e value"]);
});
describe("and accesing the first added item and adding another item", () => {
beforeEach(() => {
cache.get("a");
cache.set("d", "d value");
});
it("should contain the last recently accessed items", () => {
expect(cache.has("a")).toBe(true);
expect(cache.get("a")).toEqual("a value");
expect(cache.has("c")).toBe(true);
expect(cache.get("c")).toEqual("c value");
expect(cache.has("d")).toBe(true);
expect(cache.get("d")).toEqual("d value");
expect(Array.from(cache.values())).toEqual(["a value", "c value", "d value"]);
});
it("should not contain the least recently accessed items", () => {
expect(cache.has("b")).toBe(false);
expect(cache.get("b")).toBeUndefined();
});
});
describe("and adding 2 additional items", () => {
beforeEach(() => {
cache.set("d", "d value");
cache.set("e", "e value");
});
it("has() should return false for expired items", () => {
expect(cache.has("a")).toBe(false);
expect(cache.has("b")).toBe(false);
});
it("has() should return true for items in the caceh", () => {
expect(cache.has("c")).toBe(true);
expect(cache.has("d")).toBe(true);
expect(cache.has("e")).toBe(true);
});
it("get() should return undefined for expired items", () => {
expect(cache.get("a")).toBeUndefined();
expect(cache.get("b")).toBeUndefined();
});
it("get() should return the items in the cache", () => {
expect(cache.get("c")).toBe("c value");
expect(cache.get("d")).toBe("d value");
expect(cache.get("e")).toBe("e value");
});
it("values() should return the items in the cache", () => {
expect(Array.from(cache.values())).toEqual(["c value", "d value", "e value"]);
});
});
});
});
describe("when the cache contains some items where one of them is a replacement", () => {
beforeEach(() => {
cache.set("a", "a value");
cache.set("b", "b value");
cache.set("c", "c value");
cache.set("a", "a value 2");
cache.set("d", "d value");
});
it("should contain the last recently set items", () => {
expect(cache.has("a")).toBe(true);
expect(cache.get("a")).toEqual("a value 2");
expect(cache.has("c")).toBe(true);
expect(cache.get("c")).toEqual("c value");
expect(cache.has("d")).toBe(true);
expect(cache.get("d")).toEqual("d value");
expect(Array.from(cache.values())).toEqual(["a value 2", "c value", "d value"]);
});
});
});
});