electron/default_app/preload.ts

import { ipcRenderer, contextBridge } from 'electron'

async function getOcticonSvg (name: string) {
  try {
    const response = await fetch(`octicon/${name}.svg`)
    const div = document.createElement('div')
    div.innerHTML = await response.text()
    return div
  } catch {
    return null
  }
}

async function loadSVG (element: HTMLSpanElement) {
  for (const cssClass of element.classList) {
    if (cssClass.startsWith('octicon-')) {
      const icon = await getOcticonSvg(cssClass.substr(8))
      if (icon) {
        for (const elemClass of element.classList) {
          icon.classList.add(elemClass)
        }
        element.before(icon)
        element.remove()
        break
      }
    }
  }
}

async function initialize () {
  const electronPath = await ipcRenderer.invoke('bootstrap')

  function replaceText (selector: string, text: string) {
    const element = document.querySelector<HTMLElement>(selector)
    if (element) {
      element.innerText = text
    }
  }

  replaceText('.electron-version', `Electron v${process.versions.electron}`)
  replaceText('.chrome-version', `Chromium v${process.versions.chrome}`)
  replaceText('.node-version', `Node v${process.versions.node}`)
  replaceText('.v8-version', `v8 v${process.versions.v8}`)
  replaceText('.command-example', `${electronPath} path-to-app`)

  for (const element of document.querySelectorAll<HTMLSpanElement>('.octicon')) {
    loadSVG(element)
  }
}

contextBridge.exposeInMainWorld('electronDefaultApp', {
  initialize
})