make electron ipc support callback

ipcRenderer.js

let cbUid = 0;
const cbMap = {};
ipcRenderer.send = function(event, ...args) {
    const last = args[args.length - 1];
    if (typeof last === "function") { //callback
        cbMap[cbUid] = last;
        args[args.length - 1] = "callback-" + cbUid;
        cbUid++;
    }
    return preSend.call(ipcRenderer, event, ...args);
}
ipcRenderer.on("callback", function(event, ...args) {
    const uid = args.pop();
    cbMap[uid](...args);
    delete cbMap[uid];
});

main.js

const preOn = ipcMain.on;
ipcMain.on = function (event, cb) {
    return preOn.call(ipcMain, event, function (event, ...args) {
        const last = args[args.length - 1];
        if (last && typeof last === "string") {
            const match = args[args.length - 1].match(/callback-(\d+)/);
            if (match) {
                args[args.length - 1] = function (...args) { //cb
                    mainWindow.webContents.send("callback", ...args, match[1]);
                };
            }
        }
        return cb(event, ...args);
    });
}

usage.js

//renderer:
ipcRenderer.send("some-event", "some content", function(arg1,arg2) {
    console.log("arg1",arg1,"arg2",arg2);
});
//main:
ipcMain.on("some-event", function (event, content, cb) {
    console.log("content",content);
    cb("arg1","arg2");
});