feat: add preload-error event to webContents (#16411)

lib/sandboxed_renderer/init.js

@@ -29,7 +29,7 @@ Object.setPrototypeOf(process, EventEmitter.prototype)
 const ipcRenderer = require('@electron/internal/renderer/ipc-renderer-internal')
 
 const {
-  preloadSrc, preloadError, isRemoteModuleEnabled, isWebViewTagEnabled, process: processProps
+  preloadPath, preloadSrc, preloadError, isRemoteModuleEnabled, isWebViewTagEnabled, process: processProps
 } = ipcRenderer.sendSync('ELECTRON_BROWSER_SANDBOX_LOAD')
 
 process.isRemoteModuleEnabled = isRemoteModuleEnabled
@@ -132,6 +132,8 @@ if (!process.guestInstanceId && isWebViewTagEnabled) {
   setupWebView(v8Util, webViewImpl)
 }
 
+const errorUtils = require('@electron/internal/common/error-utils')
+
 // Wrap the script into a function executed in global scope. It won't have
 // access to the current scope, so we'll expose a few objects as arguments:
 //
@@ -151,7 +153,7 @@ if (!process.guestInstanceId && isWebViewTagEnabled) {
 // and any `require('electron')` calls in `preload.js` will work as expected
 // since browserify won't try to include `electron` in the bundle, falling back
 // to the `preloadRequire` function above.
-if (preloadSrc) {
+function runPreloadScript (preloadSrc) {
   const preloadWrapperSrc = `(function(require, process, Buffer, global, setImmediate, clearImmediate) {
   ${preloadSrc}
   })`
@@ -159,9 +161,21 @@ if (preloadSrc) {
   // eval in window scope
   const preloadFn = binding.createPreloadScript(preloadWrapperSrc)
   const { setImmediate, clearImmediate } = require('timers')
+
   preloadFn(preloadRequire, preloadProcess, Buffer, global, setImmediate, clearImmediate)
-} else if (preloadError) {
-  console.error(preloadError.stack)
+}
+
+try {
+  if (preloadSrc) {
+    runPreloadScript(preloadSrc)
+  } else if (preloadError) {
+    throw errorUtils.deserialize(preloadError)
+  }
+} catch (error) {
+  console.error(`Unable to load preload script: ${preloadPath}`)
+  console.error(`${error}`)
+
+  ipcRenderer.send('ELECTRON_BROWSER_PRELOAD_ERROR', preloadPath, errorUtils.serialize(error))
 }
 
 // Warn about security issues