chore(scaletest/dashboard): stub out initChromeDPCtx in unit tests (#13650)

scaletest/dashboard/config.go

@@ -2,6 +2,7 @@ package dashboard
 
 import (
 	"context"
+	"net/url"
 	"time"
 
 	"cdr.dev/slog"
@@ -28,6 +29,8 @@ type Config struct {
 	Screenshot func(ctx context.Context, filename string) (string, error)
 	// RandIntn is a function that returns a random number between 0 and n-1.
 	RandIntn func(int) int `json:"-"`
+	// InitChromeDPCtx is a function that initializes ChromeDP into the given context.Context.
+	InitChromeDPCtx func(ctx context.Context, log slog.Logger, u *url.URL, sessionToken string, headless bool) (context.Context, context.CancelFunc, error) `json:"-"`
 }
 
 func (c Config) Validate() error {

scaletest/dashboard/run.go

@@ -39,6 +39,9 @@ func NewRunner(client *codersdk.Client, metrics Metrics, cfg Config) *Runner {
 	if cfg.RandIntn == nil {
 		cfg.RandIntn = rand.Intn
 	}
+	if cfg.InitChromeDPCtx == nil {
+		cfg.InitChromeDPCtx = initChromeDPCtx
+	}
 	return &Runner{
 		client:  client,
 		cfg:     cfg,
@@ -70,7 +73,7 @@ func (r *Runner) runUntilDeadlineExceeded(ctx context.Context) error {
 		return xerrors.Errorf("user has no organizations")
 	}
 
-	cdpCtx, cdpCancel, err := initChromeDPCtx(ctx, r.cfg.Logger, r.client.URL, r.client.SessionToken(), r.cfg.Headless)
+	cdpCtx, cdpCancel, err := r.cfg.InitChromeDPCtx(ctx, r.cfg.Logger, r.client.URL, r.client.SessionToken(), r.cfg.Headless)
 	if err != nil {
 		return xerrors.Errorf("init chromedp ctx: %w", err)
 	}

scaletest/dashboard/run_test.go

@@ -3,6 +3,7 @@ package dashboard_test
 import (
 	"context"
 	"math/rand"
+	"net/url"
 	"runtime"
 	"sync"
 	"sync/atomic"
@@ -52,6 +53,7 @@ func Test_Run(t *testing.T) {
 		waitLoadedCalled atomic.Bool
 		screenshotCalled atomic.Bool
 	)
+	cancelDone := make(chan struct{})
 	cfg := dashboard.Config{
 		Interval: 500 * time.Millisecond,
 		Jitter:   100 * time.Millisecond,
@@ -72,6 +74,9 @@ func Test_Run(t *testing.T) {
 			return "/fake/path/to/" + name + ".png", nil
 		},
 		RandIntn: rg.Intn,
+		InitChromeDPCtx: func(ctx context.Context, _ slog.Logger, _ *url.URL, _ string, _ bool) (context.Context, context.CancelFunc, error) {
+			return ctx, func() { close(cancelDone) }, nil
+		},
 	}
 	r := dashboard.NewRunner(client, m, cfg)
 	ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitShort)
@@ -84,6 +89,8 @@ func Test_Run(t *testing.T) {
 	err, ok := <-done
 	assert.True(t, ok)
 	require.NoError(t, err)
+	_, ok = <-cancelDone
+	require.False(t, ok, "cancel should have been called")
 
 	for _, dur := range m.ObservedDurations["succeeds"] {
 		assert.NotZero(t, dur)