preload.js

const {
    contextBridge,
    ipcRenderer
} = require("electron");

// Expose protected methods that allow the renderer process to use
// the ipcRenderer without exposing the entire object
contextBridge.exposeInMainWorld("ipc", {
    send: (channel, data) => {
        // whitelist channels
        let validChannels = ["toMain"];
        if (validChannels.includes(channel)) {
            ipcRenderer.send(channel, data);
        }
    },
    receive: (channel, func) => {
        let validChannels = ["fromMain"];
        if (validChannels.includes(channel)) {
            // Deliberately strip event as it includes `sender` 
            ipcRenderer.on(channel, (event, ...args) => func(...args));
        }
    },
    sendInvoke: (channel, data) => {
        let validChannels = ["toMain"];
        if (validChannels.includes(channel)) {
            return ipcRenderer.invoke(channel, data);
        }
    }
});