serviceIframe.js

let window;
let iframe;

window = () {
    iframe.postMessage({
        // process
        parent.postMessage({})
    });
}

// iframe
iframe {
    dispatch(ACTION, payload);

    window.addEventListener('message', (event) => {
        if ([SHOW_AUTH, GRANT_SCOPE].indexOf(event.type) >= 0) {
            dispatch(event.type, event.data);
            parent.postMessage({
                ...event.data,
                payload: store.getState(),
            })
        }
    })
}

// window
export default serviceIframe(global, iframe) => {
    return (endpoint, data) => {
        let messageId = uuid.v4();
        data.id = messageId;

        return new Promise((resolve, reject) => {
            iframe.postMessage(endpoint, data);
            global.addEventListener('message', (event) => {
                let { data } = event;
                let { id } = data;

                if (id === messageId) {
                    if (data.error) {
                        return reject(new IframeRequestError(data.error));
                    }

                    return resolve(data);
                }

                global.setTimeout(() => {
                    reject(new IframeRequestError(`request ${messageId} timeout`));
                }, 3000)
            })
        })
    }
}

let ssoService = serviceIframe(window, iframe);
ssoService('GRANT_SCOPE', {
    scopes: ['write', 'read']
}).then(data => {
    let { token } = data;
    // process
})