https://github.com/mafredri/cdp/issues/45

cdp_issue45.go

// This example gives permission to access geolocation
// and fetches the current position via JavaScript.
// Tested on: cdp v0.18.7 and Chrome Canary 70.0.3532.0,
// and seems to work in both headless and headfull mode.
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"github.com/mafredri/cdp"
	"github.com/mafredri/cdp/devtool"
	"github.com/mafredri/cdp/protocol/browser"
	"github.com/mafredri/cdp/protocol/emulation"
	"github.com/mafredri/cdp/protocol/page"
	"github.com/mafredri/cdp/protocol/runtime"
	"github.com/mafredri/cdp/rpcc"
)

func main() {
	err := run(15 * time.Second)
	if err != nil {
		log.Fatal(err)
	}
}

func run(timeout time.Duration) error {
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	devt := devtool.New("http://127.0.0.1:9222")
	pt, err := devt.Get(ctx, devtool.Page)
	if err != nil {
		pt, err = devt.Create(ctx)
		if err != nil {
			return err
		}
	}

	conn, err := rpcc.DialContext(ctx, pt.WebSocketDebuggerURL)
	if err != nil {
		return err
	}
	defer conn.Close()

	c := cdp.NewClient(conn)

	domContent, err := c.Page.DOMContentEventFired(ctx)
	if err != nil {
		return err
	}
	defer domContent.Close()

	if err = c.Page.Enable(ctx); err != nil {
		return err
	}

	overrideArgs := emulation.NewSetGeolocationOverrideArgs().
		SetLatitude(10).
		SetLongitude(22).
		SetAccuracy(100)
	err = c.Emulation.SetGeolocationOverride(ctx, overrideArgs)
	if err != nil {
		return err
	}

	navArgs := page.NewNavigateArgs("https://www.google.com")
	nav, err := c.Page.Navigate(ctx, navArgs)
	if err != nil {
		return err
	}

	if _, err = domContent.Recv(); err != nil {
		return err
	}

	fmt.Printf("Page loaded with frame ID: %s\n", nav.FrameID)

	err = c.Browser.GrantPermissions(ctx,
		browser.NewGrantPermissionsArgs("https://www.google.com", []browser.PermissionType{
			browser.PermissionTypeGeolocation,
		}),
	)
	if err != nil {
		return err
	}

	eval, err := c.Runtime.Evaluate(ctx, runtime.NewEvaluateArgs(`
		new Promise((resolve, reject) => {
			navigator.geolocation.getCurrentPosition(
				(pos) => {
					// The protocol won't return this object straight, so we clone it.
					const {latitude, longitude, accuracy} = pos.coords;
					resolve({latitude, longitude, accuracy});
				},
				reject,
				{timeout: 10000}
			);
		});
		`).
		SetAwaitPromise(true).
		SetReturnByValue(true),
	)

	if err != nil {
		return err
	}
	if eval.ExceptionDetails != nil {
		return eval.ExceptionDetails
	}
	fmt.Println(eval.Result.String())

	return nil
}