From e0acb08d94279f2bf30431c188a9d9132d185f08 Mon Sep 17 00:00:00 2001 From: Joe Previte Date: Wed, 10 Feb 2021 15:28:29 -0700 Subject: [PATCH] feat: add basic test for emitter --- test/emitter.test.ts | 52 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 test/emitter.test.ts diff --git a/test/emitter.test.ts b/test/emitter.test.ts new file mode 100644 index 00000000..d3f42af1 --- /dev/null +++ b/test/emitter.test.ts @@ -0,0 +1,52 @@ +import { Emitter } from "../src/common/emitter" + +describe("emitter", () => { + describe("Emitter", () => { + it("should return an Emitter", async () => { + const HELLO_WORLD = "HELLO_WORLD" + const GOODBYE_WORLD = "GOODBYE_WORLD" + const mockCallback = jest.fn(() => "Mock function called") + const mockSecondCallback = jest.fn(() => undefined) + + const emitter = new Emitter<{ event: string; callback: () => void }>() + + const onHelloWorld = ({ event, callback }: { event: string; callback: () => void }): void => { + if (event === HELLO_WORLD) { + callback() + } + } + + const onGoodbyeWorld = ({ event, callback }: { event: string; callback: () => void }): void => { + if (event === GOODBYE_WORLD) { + callback() + } + } + + // Register the onHelloWorld listener + // and the onGoodbyeWorld + emitter.event(onHelloWorld) + emitter.event(onGoodbyeWorld) + + await emitter.emit({ event: HELLO_WORLD, callback: mockCallback }) + + // Double-check that our callback is called only once + expect(mockCallback).toHaveBeenCalled() + expect(mockCallback).toHaveBeenCalledTimes(1) + + await emitter.emit({ event: GOODBYE_WORLD, callback: mockSecondCallback }) + + // Check that it works with multiple listeners + expect(mockSecondCallback).toHaveBeenCalled() + expect(mockSecondCallback).toHaveBeenCalledTimes(1) + + // Dispose of all the listeners + emitter.dispose() + }) + + it.skip("should log an error if something goes wrong", () => { + // not sure how we're going to test this + // need to mock logger + // and then somehow throw or something in the callback + }) + }) +})