Fix k6 Hosts option incompatibility

We first update the k6 dependency (see go.mod and go.sum). Then we fix
the breaking code.

All tests pass. But, this solution is not an ideal one. As we are
marshaling and unmarshaling to grab the hosts (see
chromium/browser_type.go).

Since the whole API has changed, I needed to fix tests with the new API
as well.

A proper solution would be to use the new API in our network code,
instead of passing hosts to block to Chromium.

PS: Sorry, I couldn't keep this PR shorter. The problem was CI would
break if I sent each change as separate commits.

Author: inancgumus

chromium/browser_type.go

@@ -2,6 +2,7 @@ package chromium
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"math/rand"
@@ -161,10 +162,11 @@ func (b *BrowserType) launch(ctx context.Context, opts *common.LaunchOptions) (*
 	for k, v := range opts.Env {
 		envs = append(envs, fmt.Sprintf("%s=%s", k, v))
 	}
-	var (
-		flags   = prepareFlags(opts, &(b.vu.State()).Options)
-		dataDir = b.storage
-	)
+	flags, err := prepareFlags(opts, &(b.vu.State()).Options)
+	if err != nil {
+		return nil, fmt.Errorf("%w", err)
+	}
+	dataDir := b.storage
 	if err := dataDir.Make("", flags["user-data-dir"]); err != nil {
 		return nil, fmt.Errorf("%w", err)
 	}
@@ -279,7 +281,7 @@ func parseArgs(flags map[string]any) ([]string, error) {
 	return args, nil
 }
 
-func prepareFlags(lopts *common.LaunchOptions, k6opts *k6lib.Options) map[string]any {
+func prepareFlags(lopts *common.LaunchOptions, k6opts *k6lib.Options) (map[string]any, error) {
 	// After Puppeteer's and Playwright's default behavior.
 	f := map[string]any{
 		"disable-background-networking":                      true,
@@ -327,9 +329,11 @@ func prepareFlags(lopts *common.LaunchOptions, k6opts *k6lib.Options) map[string
 	ignoreDefaultArgsFlags(f, lopts.IgnoreDefaultArgs)
 
 	setFlagsFromArgs(f, lopts.Args)
-	setFlagsFromK6Options(f, k6opts)
+	if err := setFlagsFromK6Options(f, k6opts); err != nil {
+		return nil, err
+	}
 
-	return f
+	return f, nil
 }
 
 // ignoreDefaultArgsFlags ignores any flags in the provided slice.
@@ -356,24 +360,44 @@ func setFlagsFromArgs(flags map[string]any, args []string) {
 
 // setFlagsFromK6Options adds additional data to flags considering the k6 options.
 // Such as: "host-resolver-rules" for blocking requests.
-func setFlagsFromK6Options(flags map[string]any, k6opts *k6lib.Options) {
+func setFlagsFromK6Options(flags map[string]any, k6opts *k6lib.Options) error {
 	if k6opts == nil {
-		return
+		return nil
 	}
 
 	hostResolver := []string{}
 	if currHostResolver, ok := flags["host-resolver-rules"]; ok {
 		hostResolver = append(hostResolver, fmt.Sprintf("%s", currHostResolver))
 	}
 
-	for k, v := range k6opts.Hosts {
+	// Add the host resolver rules.
+	//
+	// This is done by marshaling the k6 hosts option to JSON and then
+	// unmarshaling it to a map[string]string. This is done because the
+	// k6 v0.42 changed Hosts from a map to types.NullHosts and doesn't
+	// expose the map anymore.
+	//
+	// TODO: A better way to do this would be to handle the resolver
+	// rules by communicating with Chromium (and then using Hosts's
+	// Match method) instead of passing the rules via the command line
+	// to Chromium.
+	var rules map[string]string
+	b, err := json.Marshal(k6opts.Hosts)
+	if err != nil {
+		return fmt.Errorf("marshaling hosts option: %w", err)
+	}
+	if err := json.Unmarshal(b, &rules); err != nil {
+		return fmt.Errorf("unmarshaling hosts option: %w", err)
+	}
+	for k, v := range rules {
 		hostResolver = append(hostResolver, fmt.Sprintf("MAP %s %s", k, v))
 	}
-
 	if len(hostResolver) > 0 {
 		sort.Strings(hostResolver)
 		flags["host-resolver-rules"] = strings.Join(hostResolver, ",")
 	}
+
+	return nil
 }
 
 // makeLogger makes and returns an extension wide logger.

chromium/browser_type_test.go

@@ -8,6 +8,8 @@ import (
 	"github.com/grafana/xk6-browser/common"
 
 	k6lib "go.k6.io/k6/lib"
+	"go.k6.io/k6/lib/types"
+	k6types "go.k6.io/k6/lib/types"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -16,8 +18,14 @@ import (
 func TestBrowserTypePrepareFlags(t *testing.T) {
 	t.Parallel()
 
-	host, err := k6lib.NewHostAddress(net.ParseIP("127.0.0.1"), "8000")
-	require.NoError(t, err)
+	// to be used by the tests below
+	host, err := k6types.NewHost(net.ParseIP("127.0.0.1"), "8000")
+	require.NoError(t, err, "failed to set up test host")
+	hosts, err := k6types.NewHosts(map[string]k6types.Host{
+		"test.k6.io":         *host,
+		"httpbin.test.k6.io": *host,
+	})
+	require.NoError(t, err, "failed to set up test hosts")
 
 	testCases := []struct {
 		flag                      string
@@ -91,10 +99,7 @@ func TestBrowserTypePrepareFlags(t *testing.T) {
 				`host-resolver-rules="MAP * www.example.com, EXCLUDE *.youtube.*"`,
 			}},
 			changeK6Opts: &k6lib.Options{
-				Hosts: map[string]*k6lib.HostAddress{
-					"test.k6.io":         host,
-					"httpbin.test.k6.io": host,
-				},
+				Hosts: types.NullHosts{Trie: hosts, Valid: true},
 			},
 			expChangedVal: "MAP * www.example.com, EXCLUDE *.youtube.*," +
 				"MAP httpbin.test.k6.io 127.0.0.1:8000,MAP test.k6.io 127.0.0.1:8000",
@@ -141,7 +146,8 @@ func TestBrowserTypePrepareFlags(t *testing.T) {
 				tc.pre(t)
 			}
 
-			flags := prepareFlags(&common.LaunchOptions{}, nil)
+			flags, err := prepareFlags(&common.LaunchOptions{}, nil)
+			require.NoError(t, err, "failed to prepare flags")
 
 			if tc.expInitVal != nil {
 				require.Contains(t, flags, tc.flag)
@@ -151,7 +157,8 @@ func TestBrowserTypePrepareFlags(t *testing.T) {
 			}
 
 			if tc.changeOpts != nil || tc.changeK6Opts != nil {
-				flags = prepareFlags(tc.changeOpts, tc.changeK6Opts)
+				flags, err = prepareFlags(tc.changeOpts, tc.changeK6Opts)
+				require.NoError(t, err, "failed to prepare flags")
 				if tc.expChangedVal != nil {
 					assert.Equal(t, tc.expChangedVal, flags[tc.flag])
 				} else {

go.mod

@@ -4,7 +4,7 @@ go 1.19
 
 require (
 	github.com/chromedp/cdproto v0.0.0-20221023212508-67ada9507fb2
-	github.com/dop251/goja v0.0.0-20221025095645-e66ebd086f45
+	github.com/dop251/goja v0.0.0-20221106173738-3b8a68ca89b4
 	github.com/fatih/color v1.13.0
 	github.com/gorilla/websocket v1.5.0
 	github.com/hashicorp/go-multierror v1.1.1
@@ -13,44 +13,69 @@ require (
 	github.com/oxtoacart/bpool v0.0.0-20190530202638-03653db5a59c
 	github.com/sirupsen/logrus v1.9.0
 	github.com/stretchr/testify v1.8.0
-	go.k6.io/k6 v0.41.0
+	go.k6.io/k6 v0.41.1-0.20221206194017-a2ab89abfdc8
 	golang.org/x/exp v0.0.0-20221106115401-f9659909a136
 	golang.org/x/net v0.1.0
 	gopkg.in/guregu/null.v3 v3.5.0
 )
 
 require (
 	github.com/Azure/go-ntlmssp v0.0.0-20220621081337-cb9428e4ac1e // indirect
+	github.com/DataDog/datadog-go v0.0.0-20180330214955-e67964b4021a // indirect
 	github.com/PuerkitoBio/goquery v1.8.0 // indirect
 	github.com/Soontao/goHttpDigestClient v0.0.0-20170320082612-6d28bb1415c5 // indirect
 	github.com/andybalholm/brotli v1.0.4 // indirect
 	github.com/andybalholm/cascadia v1.3.1 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/chromedp/sysutil v1.0.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/dlclark/regexp2 v1.7.0 // indirect
+	github.com/go-redis/redis/v8 v8.11.5 // indirect
 	github.com/go-sourcemap/sourcemap v2.1.4-0.20211119122758-180fcef48034+incompatible // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/golang/snappy v0.0.4 // indirect
+	github.com/grafana/xk6-output-prometheus-remote v0.0.8 // indirect
+	github.com/grafana/xk6-redis v0.1.1 // indirect
+	github.com/grafana/xk6-timers v0.1.2 // indirect
+	github.com/grafana/xk6-websockets v0.1.6 // indirect
 	github.com/hashicorp/errwrap v1.1.0 // indirect
+	github.com/inconshreveable/mousetrap v1.0.0 // indirect
+	github.com/influxdata/influxdb1-client v0.0.0-20190402204710-8ff2fc3824fc // indirect
+	github.com/jhump/protoreflect v1.13.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/klauspost/compress v1.15.11 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.16 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
 	github.com/mstoykov/atlas v0.0.0-20220811071828-388f114305dd // indirect
+	github.com/mstoykov/envconfig v1.4.1-0.20220114105314-765c6d8c76f1 // indirect
+	github.com/mstoykov/k6-taskqueue-lib v0.1.0 // indirect
 	github.com/nu7hatch/gouuid v0.0.0-20131221200532-179d4d0c4d8d // indirect
 	github.com/onsi/ginkgo v1.16.5 // indirect
 	github.com/onsi/gomega v1.18.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_golang v1.14.1-0.20221122130035-8b6e68085b10 // indirect
+	github.com/prometheus/client_model v0.3.0 // indirect
+	github.com/prometheus/common v0.37.0 // indirect
+	github.com/prometheus/procfs v0.8.0 // indirect
 	github.com/serenize/snaker v0.0.0-20201027110005-a7ad2135616e // indirect
 	github.com/spf13/afero v1.9.2 // indirect
+	github.com/spf13/cobra v1.4.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/tidwall/gjson v1.14.3 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.1 // indirect
+	go.buf.build/grpc/go/gogo/protobuf v1.4.9 // indirect
+	go.buf.build/grpc/go/prometheus/prometheus v1.4.4 // indirect
 	golang.org/x/crypto v0.1.0 // indirect
 	golang.org/x/sys v0.1.0 // indirect
+	golang.org/x/term v0.1.0 // indirect
 	golang.org/x/text v0.4.0 // indirect
 	golang.org/x/time v0.1.0 // indirect
-	google.golang.org/genproto v0.0.0-20220308174144-ae0e22291548 // indirect
+	google.golang.org/genproto v0.0.0-20220502173005-c8bf987b8c21 // indirect
 	google.golang.org/grpc v1.49.0 // indirect
-	google.golang.org/protobuf v1.27.1 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )