review: fix tab alignment, rename buildTelemetryParam, validate --seq, add tests

Author: archandatta

README.md

@@ -212,7 +212,9 @@ Commands with JSON output support:
   - `--start-url <url>` - Initial page to open on launch
   - `--pool-id <id>` - Acquire a browser from the specified pool (mutually exclusive with --pool-name; ignores other session flags)
   - `--pool-name <name>` - Acquire a browser from the pool name (mutually exclusive with --pool-id; ignores other session flags)
-  - `--telemetry=all` - Enable telemetry for all categories; `--telemetry=off` to disable; `--telemetry=network=on,page=off` for per-category
+  - `--telemetry=all` - Enable telemetry for all categories
+  - `--telemetry=off` - Disable telemetry
+  - `--telemetry=<list>` - Per-category config, e.g. `--telemetry=network=on,page=off`
   - `--output json`, `-o json` - Output raw JSON object
   - _Note: When a pool is specified, omit other session configuration flags—pool settings determine profile, proxy, viewport, etc._
 - `kernel browsers delete <id>` - Delete a browser

cmd/browsers.go

@@ -426,7 +426,7 @@ func (b BrowsersCmd) Create(ctx context.Context, in BrowsersCreateInput) error {
 	}
 
 	if in.Telemetry != "" {
-		t, err := applyTelemetryParam(in.Telemetry)
+		t, err := buildTelemetryParam(in.Telemetry)
 		if err != nil {
 			return err
 		}
@@ -627,7 +627,7 @@ func (b BrowsersCmd) Update(ctx context.Context, in BrowsersUpdateInput) error {
 
 	// Handle telemetry changes
 	if in.Telemetry != "" {
-		t, err := applyTelemetryParam(in.Telemetry)
+		t, err := buildTelemetryParam(in.Telemetry)
 		if err != nil {
 			return err
 		}

cmd/browsers_telemetry.go

@@ -64,8 +64,8 @@ func parseTelemetryCategories(s string) (kernel.BrowserTelemetryCategoriesConfig
 	return p, nil
 }
 
-// applyTelemetryParam converts a --telemetry flag value to the API param.
-func applyTelemetryParam(s string) (kernel.BrowserTelemetryRequestConfigParam, error) {
+// buildTelemetryParam converts a --telemetry flag value to the API param.
+func buildTelemetryParam(s string) (kernel.BrowserTelemetryRequestConfigParam, error) {
 	switch s {
 	case "all":
 		return kernel.BrowserTelemetryRequestConfigParam{Enabled: kernel.Opt(true)}, nil
@@ -120,6 +120,9 @@ func (b BrowsersCmd) TelemetryStream(ctx context.Context, in BrowsersTelemetrySt
 	if err != nil {
 		return util.CleanedUpSdkError{Err: err}
 	}
+	if in.Seq < -1 {
+		return fmt.Errorf("--seq must be >= 0 (use --seq=0 to resume from the beginning, or omit to stream from now)")
+	}
 	params := kernel.BrowserTelemetryStreamParams{}
 	if in.Seq >= 0 {
 		params.LastEventID = kernel.Opt(strconv.FormatInt(in.Seq, 10))
@@ -142,7 +145,7 @@ func (b BrowsersCmd) TelemetryStream(ctx context.Context, in BrowsersTelemetrySt
 			continue
 		}
 		ts := time.UnixMicro(ev.Event.Ts).Local().Format("15:04:05")
-		pterm.Printf("%s  %-11s  %s\n", ts, "["+cat+"]", ev.Event.Type)
+		pterm.Printf("%s\t[%s]\t%s\n", ts, cat, ev.Event.Type)
 	}
 	if err := stream.Err(); err != nil {
 		return util.CleanedUpSdkError{Err: err}

cmd/browsers_telemetry_test.go

@@ -1,8 +1,11 @@
 package cmd
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
+	"io"
+	"os"
 	"testing"
 
 	kernel "github.com/kernel/kernel-go-sdk"
@@ -11,6 +14,24 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+// captureStdout redirects os.Stdout for the duration of the test and returns
+// the captured output. Needed for paths that use fmt.Println rather than pterm.
+func captureStdout(t *testing.T, fn func()) string {
+	t.Helper()
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatalf("os.Pipe: %v", err)
+	}
+	old := os.Stdout
+	os.Stdout = w
+	fn()
+	w.Close()
+	os.Stdout = old
+	var buf bytes.Buffer
+	io.Copy(&buf, r)
+	return buf.String()
+}
+
 type FakeBrowserTelemetryService struct {
 	StreamFunc func() *ssestream.Stream[kernel.BrowserTelemetryStreamResponse]
 }
@@ -101,13 +122,43 @@ func TestTelemetryStream_EventsFlow_JSON(t *testing.T) {
 	}}
 	b := BrowsersCmd{browsers: fakeBrowsers, telemetry: fakeTelemetry}
 
+	var err error
+	out := captureStdout(t, func() {
+		err = b.TelemetryStream(context.Background(), BrowsersTelemetryStreamInput{
+			Identifier: "session123",
+			Output:     "json",
+			Seq:        -1,
+		})
+	})
+
+	assert.NoError(t, err)
+	assert.Contains(t, out, "network_response")
+}
+
+type capturingTelemetryService struct {
+	captured kernel.BrowserTelemetryStreamParams
+}
+
+func (c *capturingTelemetryService) StreamStreaming(ctx context.Context, id string, query kernel.BrowserTelemetryStreamParams, opts ...option.RequestOption) *ssestream.Stream[kernel.BrowserTelemetryStreamResponse] {
+	c.captured = query
+	return makeStream([]kernel.BrowserTelemetryStreamResponse{})
+}
+
+func TestTelemetryStream_SeqZeroSetsLastEventID(t *testing.T) {
+	fakeBrowsers := &FakeBrowsersService{GetFunc: func(ctx context.Context, id string, query kernel.BrowserGetParams, opts ...option.RequestOption) (*kernel.BrowserGetResponse, error) {
+		return &kernel.BrowserGetResponse{SessionID: id}, nil
+	}}
+	capSvc := &capturingTelemetryService{}
+	b := BrowsersCmd{browsers: fakeBrowsers, telemetry: capSvc}
+
 	err := b.TelemetryStream(context.Background(), BrowsersTelemetryStreamInput{
 		Identifier: "session123",
-		Output:     "json",
-		Seq:        -1,
+		Seq:        0,
 	})
 
 	assert.NoError(t, err)
+	assert.True(t, capSvc.captured.LastEventID.Valid())
+	assert.Equal(t, "0", capSvc.captured.LastEventID.Value)
 }
 
 func makeEvent(t *testing.T, raw string) kernel.BrowserTelemetryEventUnion {