preload.js

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

const {read, slice} = require("./src/main/fileReader.js");


// Expose protected methods that allow the renderer process to use
// the ipcRenderer without exposing the entire object
contextBridge.exposeInMainWorld(
	"api", {
		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));
			}
		},

		read: (path) => {
			return read(path)
		},

		slice: (path, start, end) => {
			return slice(path, start, end);
		}
	})