Is it possible to capture error messages related to CORS, CSP violations, mixed-content violations, etc.?

[jub0bs]

What versions are you running?

$ go list -m github.com/chromedp/chromedp
github.com/chromedp/chromedp v0.9.5
$ chromium --version
Chromium 125.0.6399.0
$ go version
go version go1.22.1 darwin/amd64

What did you do? Include clear steps.

package main

import (
	"context"
	"fmt"
	"log"

	"github.com/chromedp/cdproto/runtime"
	"github.com/chromedp/chromedp"
)

const (
	url            = "https://example.com/"
	crossOriginURL = "https://www.example.com/robots.txt"
)

func main() {
	ctx, cancel := chromedp.NewContext(context.Background())
	defer cancel()

	chromedp.ListenTarget(ctx, func(ev interface{}) {
		switch ev := ev.(type) {
		case *runtime.EventExceptionThrown:
			fmt.Println(ev.ExceptionDetails.Error())
		}
	})

	err := chromedp.Run(ctx,
		chromedp.Navigate(url),
		chromedp.Evaluate(`fetch("`+crossOriginURL+`")`, nil),
	)
	if err != nil {
		log.Fatal(err)
	}
}

What did you expect to see?

I expected the output to contain the following CORS error message:

Access to fetch at 'https://www.example.com/robots.txt' from origin 'https://example.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

What did you see instead?

Nothing.