Fixed cookie support

Closes #289

Closes #286

js/common/state.go

@@ -22,6 +22,7 @@ package common
 
 import (
 	"net/http"
+	"net/http/cookiejar"
 
 	"github.com/loadimpact/k6/lib"
 	"github.com/loadimpact/k6/lib/netext"
@@ -42,9 +43,8 @@ type State struct {
 
 	// Networking equipment.
 	HTTPTransport http.RoundTripper
-
-	// Also expose the underlying dialer
-	Dialer *netext.Dialer
+	Dialer        *netext.Dialer
+	CookieJar     *cookiejar.Jar
 
 	// Sample buffer, emitted at the end of the iteration.
 	Samples []stats.Sample

js/modules/k6/http/http.go

@@ -188,6 +188,7 @@ func (*HTTP) request(ctx context.Context, rt *goja.Runtime, state *common.State,
 	}
 	client := http.Client{
 		Transport: state.HTTPTransport,
+		Jar:       state.CookieJar,
 		Timeout:   timeout,
 		CheckRedirect: func(req *http.Request, via []*http.Request) error {
 			max := int(state.Options.MaxRedirects.Int64)

js/runner.go

@@ -25,6 +25,7 @@ import (
 	"crypto/tls"
 	"net"
 	"net/http"
+	"net/http/cookiejar"
 	"time"
 
 	"github.com/dop251/goja"
@@ -167,12 +168,18 @@ type VU struct {
 }
 
 func (u *VU) RunOnce(ctx context.Context) ([]stats.Sample, error) {
+	cookieJar, err := cookiejar.New(nil)
+	if err != nil {
+		return nil, err
+	}
+
 	state := &common.State{
 		Logger:        u.Runner.Logger,
 		Options:       u.Runner.Bundle.Options,
 		Group:         u.Runner.defaultGroup,
 		HTTPTransport: u.HTTPTransport,
 		Dialer:        u.Dialer,
+		CookieJar:     cookieJar,
 	}
 	u.Dialer.BytesRead = &state.BytesRead
 	u.Dialer.BytesWritten = &state.BytesWritten
@@ -184,7 +191,7 @@ func (u *VU) RunOnce(ctx context.Context) ([]stats.Sample, error) {
 	u.Runtime.Set("__ITER", u.Iteration)
 	u.Iteration++
 
-	_, err := u.Default(goja.Undefined())
+	_, err = u.Default(goja.Undefined())
 
 	t := time.Now()
 	samples := append(state.Samples,

js/runner_test.go

@@ -512,3 +512,51 @@ func TestVUIntegrationHTTP2(t *testing.T) {
 		})
 	}
 }
+
+func TestVUIntegrationCookies(t *testing.T) {
+	r1, err := New(&lib.SourceData{
+		Filename: "/script.js",
+		Data: []byte(`
+			import http from "k6/http";
+			export default function() {
+				let preRes = http.get("https://httpbin.org/cookies");
+				if (preRes.status != 200) { throw new Error("wrong status (pre): " + preRes.status); }
+				if (preRes.json().cookies.k1 || preRes.json().cookies.k2) {
+					throw new Error("cookies persisted: " + preRes.body);
+				}
+
+				let res = http.get("https://httpbin.org/cookies/set?k2=v2&k1=v1");
+				if (res.status != 200) { throw new Error("wrong status: " + res.status) }
+				if (res.json().cookies.k1 != "v1" || res.json().cookies.k2 != "v2") {
+					throw new Error("wrong cookies: " + res.body);
+				}
+			}
+		`),
+	}, afero.NewMemMapFs())
+	if !assert.NoError(t, err) {
+		return
+	}
+	r1.ApplyOptions(lib.Options{
+		Throw:        null.BoolFrom(true),
+		MaxRedirects: null.IntFrom(10),
+	})
+
+	r2, err := NewFromArchive(r1.MakeArchive())
+	if !assert.NoError(t, err) {
+		return
+	}
+
+	runners := map[string]*Runner{"Source": r1, "Archive": r2}
+	for name, r := range runners {
+		t.Run(name, func(t *testing.T) {
+			vu, err := r.NewVU()
+			if !assert.NoError(t, err) {
+				return
+			}
+			for i := 0; i < 2; i++ {
+				_, err = vu.RunOnce(context.Background())
+				assert.NoError(t, err)
+			}
+		})
+	}
+}