Prompt for login before emulator selection on first run (#270)

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

Author: gtsiolis

internal/ui/run.go

@@ -6,6 +6,7 @@ import (
 	"os"
 
 	tea "github.com/charmbracelet/bubbletea"
+	"github.com/localstack/lstk/internal/auth"
 	"github.com/localstack/lstk/internal/container"
 	"github.com/localstack/lstk/internal/output"
 	"github.com/localstack/lstk/internal/runtime"
@@ -75,6 +76,19 @@ func Run(parentCtx context.Context, runOpts RunOptions) error {
 			p.Send(runDoneMsg{})
 			return
 		}
+		// Resolve the auth token before any emulator-selection prompt so the user
+		// logs in first and only configures an emulator once they're authenticated.
+		// container.Start still calls GetToken as a safety net for non-interactive
+		// callers; once the token is in opts.AuthToken (or the keyring), it returns
+		// immediately.
+		if authErr := resolveAuthToken(ctx, sink, &runOpts); authErr != nil {
+			if errors.Is(authErr, context.Canceled) {
+				return
+			}
+			err = authErr
+			p.Send(runErrMsg{err: authErr})
+			return
+		}
 		if runOpts.NeedsEmulatorSelection {
 			newContainers, selErr := container.SelectEmulator(ctx, sink, runOpts.ConfigPath)
 			if selErr != nil {
@@ -115,6 +129,23 @@ func Run(parentCtx context.Context, runOpts RunOptions) error {
 	return nil
 }
 
+// resolveAuthToken ensures the user is authenticated before the start flow
+// continues. On success, the resolved token is written to opts.StartOptions.AuthToken
+// so container.Start short-circuits its own auth call.
+func resolveAuthToken(ctx context.Context, sink output.Sink, opts *RunOptions) error {
+	tokenStorage, err := auth.NewTokenStorage(opts.StartOptions.ForceFileKeyring, opts.StartOptions.Logger)
+	if err != nil {
+		return err
+	}
+	a := auth.New(sink, opts.StartOptions.PlatformClient, tokenStorage, opts.StartOptions.AuthToken, opts.StartOptions.WebAppURL, true, "")
+	token, err := a.GetToken(ctx)
+	if err != nil {
+		return err
+	}
+	opts.StartOptions.AuthToken = token
+	return nil
+}
+
 func RunMessage(parentCtx context.Context, event output.MessageEvent) error {
 	return runWithTUI(parentCtx, withoutHeader(), func(ctx context.Context, sink output.Sink) error {
 		sink.Emit(event)

test/integration/emulator_select_test.go

@@ -114,6 +114,62 @@ func TestFirstRunShowsEmulatorSelectionPrompt(t *testing.T) {
 	<-outputCh
 }
 
+func TestFirstRunPromptsForLoginBeforeEmulatorSelection(t *testing.T) {
+	t.Parallel()
+	if runtime.GOOS == "windows" {
+		t.Skip("PTY not supported on Windows")
+	}
+
+	mockServer := createMockAPIServer(t, "test-license-token", true)
+	defer mockServer.Close()
+
+	tmpHome := t.TempDir()
+	require.NoError(t, os.MkdirAll(filepath.Join(tmpHome, ".config"), 0755))
+	e := env.Environ(testEnvWithHome(tmpHome, tmpHome)).
+		Without(env.AuthToken).
+		With(env.APIEndpoint, mockServer.URL).
+		With(env.DisableEvents, "1")
+
+	// No config exists so this is a first run; no token means login fires before emulator selection.
+	configPath, _, err := runLstk(t, testContext(t), "", e, "config", "path")
+	require.NoError(t, err)
+	require.NoFileExists(t, configPath)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, binaryPath(), "start")
+	cmd.Env = e
+
+	ptmx, err := pty.Start(cmd)
+	require.NoError(t, err, "failed to start lstk in PTY")
+	defer func() { _ = ptmx.Close() }()
+
+	out := &syncBuffer{}
+	outputCh := make(chan struct{})
+	go func() {
+		_, _ = io.Copy(out, ptmx)
+		close(outputCh)
+	}()
+
+	require.Eventually(t, func() bool {
+		return bytes.Contains(out.Bytes(), []byte("Press any key when complete"))
+	}, 10*time.Second, 100*time.Millisecond, "auth prompt should appear on first run when no token is set")
+
+	assert.NotContains(t, out.String(), "Which emulator would you like to use?",
+		"emulator selection prompt must not appear before auth completes")
+
+	_, err = ptmx.Write([]byte("\r"))
+	require.NoError(t, err)
+
+	require.Eventually(t, func() bool {
+		return bytes.Contains(out.Bytes(), []byte("Which emulator would you like to use?"))
+	}, 10*time.Second, 100*time.Millisecond, "emulator selection prompt should appear after auth completes")
+
+	cancel()
+	<-outputCh
+}
+
 func TestFirstRunNonInteractiveEmitsDefaultEmulatorNote(t *testing.T) {
 	t.Parallel()
 	tmpHome := t.TempDir()