typescript-substitute.example.ts

import { Arg, Substitute } from '@fluffy-spoon/substitute';

/**
 * @see https://www.npmjs.com/package/@fluffy-spoon/substitute
 */
describe('Mock functionality works correctly', () => {
    it('tmp', () => {
        interface Element {
            readonly destroy: () => void;
        }

        interface ParentMethod {
            readonly mount: () => Element;
        }

        interface ChildMethod1 extends ParentMethod {
            readonly name: string;
        }

        interface ChildMethod2 extends ParentMethod {
            readonly name: string;
        }

        interface Api {
            readonly child1: ChildMethod1;
            readonly child2: ChildMethod2;
        }

        const api = Substitute.for<Api>();
        const spy1 = jest.fn();
        const spy2 = jest.fn();

        // @ts-ignore
        api.child1.mount().returns(Substitute.for<Element>());
        // @ts-ignore
        api.child2.mount().returns(Substitute.for<Element>());

        api.child1
            .mount()
            .destroy()
            // @ts-ignore
            .mimicks(spy1);

        api.child2
            .mount()
            .destroy()
            // @ts-ignore
            .mimicks(spy2);

        const el = api.child1.mount();
        el.destroy();

        expect(spy1).toBeCalledTimes(1);
        expect(spy2).not.toHaveBeenCalled();

        interface ComponentProps {
            readonly api: Api;
        }

        interface ComponentState {
            readonly element: Element
        }

        class TmpParentComponent extends React.Component<ComponentProps, ComponentState> {
            componentDidMount() {
                this.setState({ element: this.props.api.child1.mount() });
            }

            componentWillUnmount() {
                this.state.element.destroy();
            }

            render() {
                return <div/>;
            }
        }

        const wrapper = mount(<TmpParentComponent api={api}/>);
        expect(spy1).toBeCalledTimes(1);
        expect(spy2).not.toHaveBeenCalled();

        wrapper.unmount();

        expect(spy1).toBeCalledTimes(2);
        expect(spy2).not.toHaveBeenCalled();
    });
});