sinonjs/sinon#2501

// This works correctly in Sinon 14: `npm i sinon@14` // Breaks in 15.0.1 and 15.0.2: `npm i sinon@15.0.1` or `npm i sinon@15.0.2` breaks require('@fatso83/mini-mocha').install(); const sinon = require("sinon"); class TestService { doSomething(value) { return `TestService:doSomething:${value}`; } doSomethingElse(value) { return `TestService:doSomethingElse:${value}`; } } describe("sinon breaking change", () => { it("should call through", async () => { const stubTestService = sinon.createStubInstance(TestService); stubTestService.doSomething.callThrough(); console.log("val1: ", stubTestService.doSomething("hei")); console.log("val2: ", stubTestService.doSomethingElse("hei")); expect(stubTestService.doSomething("test1")).toEqual( "TestService:doSomething:test1" ); expect(stubTestService.doSomethingElse("test2")).toEqual(undefined); }); });