I just started playing with electron and as a playground I opted to draft a raw basic javascript console.

The code is entered on a <textarea> and once a button is pushed the code gets executed with webContent.executeJavaScript and the result is shown in an output <div/>. Clearly enough I would also like to show as output any eventual error message.

Not being able to find in the electron documentation a clear way to do it I came up with a solution (below reduced to the bare minimum) which does not really make me happy:

// main.js
ipcMain.handle('runjs', (event, code ) => 
    mainWindow.webContents.executeJavaScript(code, true)
);

// preload.js
const { ipcRenderer, contextBridge } = require('electron');

contextBridge.exposeInMainWorld('api', {
    runjs: code => ipcRenderer.invoke('runjs', code),
});

// triggering component
import React from 'react'

export default ({code}) => {
    const onClick = () => window.api.runjs(`
        (() => {
            try {
                var t = eval('${code.replace(/\n|\r/mg, '')}');
                return { result: t }
            } catch (e) {
              return { error: e }
            }
          })()
    `).then(res => {
        // dispatch to decide what to do in case of 'error' or 'result' in res
        /// and consume the result in the output
    })
    .catch(e => {
        // not useful to understand the code error
    })
    return <button onClick={onClick}>RUN</button>
)

It's working but I am sure there has to be a better way.

How should that be properly handled ?