fix: print the telemetry notice before any event is sent

CHANGELOG.md

@@ -14,8 +14,9 @@ This project uses [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 - Telemetry is on by default for interactive sessions. CI and agent sessions still send nothing
   unless `DATATF_TELEMETRY=1` is set. `DO_NOT_TRACK`, `DATATF_TELEMETRY=0`, and
   `datatf telemetry disable` still opt out. Invalid consent files still turn telemetry off.
-- Interactive `inventory` and `export` commands print a one-line telemetry notice on stderr until
-  you save a preference with `datatf telemetry enable` or `datatf telemetry disable`.
+- `inventory` and `export` print a short telemetry notice on stderr before they run and before any
+  event is sent, in every output mode, until you save a preference with `datatf telemetry enable`
+  or `datatf telemetry disable`.
 
 ## [1.0.2] - 2026-09-09
 

docs/telemetry.md

@@ -20,8 +20,9 @@ datatf telemetry disable
 
 `enable` saves your consent for future eligible commands.
 `disable` saves an opt-out. It does not delete events that the collector already received.
-Until you save a preference, interactive `inventory` and `export` commands print a short notice
-on stderr with a link to this page. `--json`, `--plain`, and `--quiet` suppress the notice.
+Until you save a preference, `inventory` and `export` print a short notice on stderr with a link
+to this page before they run and before any event is sent. The notice prints in every output mode,
+including `--json`, `--plain`, `--quiet`, and redirected output. `enable` or `disable` silences it.
 `status --json` shows the effective preference, its source, and the settings path.
 
 `preview` prints a sample JSON event through the same encoder that sends events.

internal/cli/telemetry.go

@@ -86,11 +86,14 @@ func (rc *runtime) telemetryAction(action string) error {
 	return nil
 }
 
-// writeTelemetryNotice tells interactive users about default telemetry until they save a preference.
+// writeTelemetryNotice runs before the command and before any event leaves the machine.
+// It prints in every output mode until the user saves a preference, so a redirected,
+// --json, --plain, or --quiet session still learns about default telemetry.
 func (rc *runtime) writeTelemetryNotice() {
 	_, _ = fmt.Fprintf(rc.stderr,
-		"\nDataTF sends optional usage metrics without workspace metadata. Notice: %s\n"+
-			"Run `datatf telemetry disable` or set DATATF_TELEMETRY=0 to opt out.\n",
+		"DataTF sends optional usage metrics without workspace metadata. Notice: %s\n"+
+			"Run `datatf telemetry disable` or set DATATF_TELEMETRY=0 to opt out. "+
+			"Run `datatf telemetry enable` to keep it and silence this notice.\n",
 		telemetry.Notice)
 }
 
@@ -115,19 +118,18 @@ func (rc *runtime) beginUsage(command string) {
 		Command: command, Scope: "none", Outcome: "complete", ErrorCode: "none",
 	}
 	rc.usageStarted = time.Now()
+	if status := telemetryStatus(); status.Enabled && status.Source == "default" {
+		rc.writeTelemetryNotice()
+	}
 }
 
 func (rc *runtime) finishUsage(failed bool) {
 	if rc.usage == nil {
 		return
 	}
-	status := telemetryStatus()
-	if !status.Enabled {
+	if !telemetryStatus().Enabled {
 		return
 	}
-	if status.Source == "default" && rc.updateOutputAllowed() {
-		rc.writeTelemetryNotice()
-	}
 	if failed {
 		rc.usage.Outcome = "error"
 		switch rc.usage.ErrorCode {

internal/cli/telemetry_test.go

@@ -315,40 +315,45 @@ func TestTelemetryNoticeUntilPreferenceSaved(t *testing.T) {
 	t.Setenv("DATATF_TELEMETRY", "")
 	t.Setenv("DATATF_NO_UPDATE_NOTIFIER", "1")
 	oldTerminal := terminalOutput
-	terminalOutput = func(io.Writer) bool { return true }
+	terminalOutput = func(io.Writer) bool { return false }
 	t.Cleanup(func() { terminalOutput = oldTerminal })
-	out := t.TempDir()
+	out := func() string { return t.TempDir() }
 
-	code, stdout, stderr := run(t, "inventory", "--resources", "warehouses", "--out", out)
-	if code != exitOK || !strings.Contains(stderr, "datatf telemetry disable") ||
-		!strings.Contains(stderr, telemetry.Notice) {
-		t.Fatalf("default consent must print a notice: %d %s", code, stderr)
+	// The notice must reach redirected, --json, --plain, and --quiet sessions before any send.
+	for _, flag := range []string{"", "--json", "--plain", "--quiet"} {
+		args := []string{"inventory", "--resources", "warehouses", "--out", out()}
+		if flag != "" {
+			args = append(args, flag)
+		}
+		code, stdout, stderr := run(t, args...)
+		if code != exitOK || !strings.Contains(stderr, "datatf telemetry disable") ||
+			!strings.Contains(stderr, telemetry.Notice) {
+			t.Fatalf("%v: default consent must print a notice: %d %s", args, code, stderr)
+		}
+		if strings.Contains(stdout, "telemetry") {
+			t.Fatalf("%v: notice changed stdout", args)
+		}
 	}
-	if strings.Contains(stdout, "telemetry") {
-		t.Fatal("notice changed stdout")
+	if len(*events) != 4 {
+		t.Fatalf("default consent must send one event per run: %v", *events)
 	}
-	if len(*events) != 1 {
-		t.Fatalf("default consent must send one event: %v", *events)
+	if _, _, stderr := run(t, "telemetry", "status"); strings.Contains(stderr, "telemetry disable") {
+		t.Fatalf("notice for an offline control: %s", stderr)
 	}
 
-	for _, args := range [][]string{
-		{"inventory", "--resources", "warehouses", "--out", out, "--json"},
-		{"inventory", "--resources", "warehouses", "--out", out, "--plain"},
-		{"inventory", "--resources", "warehouses", "--out", out, "--quiet"},
-		{"telemetry", "status"},
-	} {
-		if _, _, stderr := run(t, args...); strings.Contains(stderr, "telemetry disable") {
-			t.Fatalf("notice for %v: %s", args, stderr)
-		}
+	// A command that fails after it starts still prints the notice before its event is sent.
+	code, _, stderr := run(t, "export", "--scope", "invalid", "--out", out())
+	if code == exitOK || !strings.Contains(stderr, "telemetry disable") || len(*events) != 5 {
+		t.Fatalf("failed command must notify before sending: %d %s %d", code, stderr, len(*events))
 	}
 
 	for _, action := range []string{"enable", "disable"} {
 		run(t, "telemetry", action)
-		if _, _, stderr := run(t, "inventory", "--resources", "warehouses", "--out", out); strings.Contains(stderr, "telemetry disable") {
+		if _, _, stderr := run(t, "inventory", "--resources", "warehouses", "--out", out()); strings.Contains(stderr, "telemetry disable") {
 			t.Fatalf("notice after saved %s: %s", action, stderr)
 		}
 	}
-	if len(*events) != 5 {
+	if len(*events) != 6 {
 		t.Fatalf("expected events for default and enabled runs only: %d", len(*events))
 	}
 }