force UI teardown when event is sourced from a signal interrupt (#453)

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

cmd/event_loop.go

@@ -13,7 +13,7 @@ import (
 // eventLoop listens to worker errors (from execution path), worker events (from a partybus subscription), and
 // signal interrupts. Is responsible for handling each event relative to a given UI an to coordinate eventing until
 // an eventual graceful exit.
-// nolint:gocognit
+// nolint:gocognit,funlen
 func eventLoop(workerErrs <-chan error, signals <-chan os.Signal, subscription *partybus.Subscription, ux ui.UI, cleanupFn func()) error {
 	defer cleanupFn()
 	events := subscription.Events()
@@ -23,6 +23,7 @@ func eventLoop(workerErrs <-chan error, signals <-chan os.Signal, subscription *
 	}
 
 	var retErr error
+	var forceTeardown bool
 
 	for {
 		if workerErrs == nil && events == nil {
@@ -66,10 +67,11 @@ func eventLoop(workerErrs <-chan error, signals <-chan os.Signal, subscription *
 			// of processing.
 			events = nil
 			workerErrs = nil
+			forceTeardown = true
 		}
 	}
 
-	if err := ux.Teardown(); err != nil {
+	if err := ux.Teardown(forceTeardown); err != nil {
 		retErr = multierror.Append(retErr, err)
 	}
 

cmd/event_loop_test.go

@@ -37,7 +37,7 @@ func (u *uiMock) Handle(event partybus.Event) error {
 	return u.Called(event).Error(0)
 }
 
-func (u *uiMock) Teardown() error {
+func (u *uiMock) Teardown(_ bool) error {
 	u.t.Logf("UI Teardown called")
 	return u.Called().Error(0)
 }

internal/ui/ephemeral_terminal_ui.go

@@ -77,7 +77,7 @@ func (h *ephemeralTerminalUI) Handle(event partybus.Event) error {
 	case event.Type == syftEvent.PresenterReady:
 		// we need to close the screen now since signaling the the presenter is ready means that we
 		// are about to write bytes to stdout, so we should reset the terminal state first
-		h.closeScreen()
+		h.closeScreen(false)
 
 		if err := handleCatalogerPresenterReady(event); err != nil {
 			log.Errorf("unable to show %s event: %+v", event.Type, err)
@@ -105,11 +105,13 @@ func (h *ephemeralTerminalUI) openScreen() error {
 	return nil
 }
 
-func (h *ephemeralTerminalUI) closeScreen() {
+func (h *ephemeralTerminalUI) closeScreen(force bool) {
 	// we may have other background processes still displaying progress, wait for them to
 	// finish before discontinuing dynamic content and showing the final report
 	if !h.frame.IsClosed() {
-		h.waitGroup.Wait()
+		if !force {
+			h.waitGroup.Wait()
+		}
 		h.frame.Close()
 		// TODO: there is a race condition within frame.Close() that sometimes leads to an extra blank line being output
 		frame.Close()
@@ -130,8 +132,8 @@ func (h *ephemeralTerminalUI) flushLog() {
 	}
 }
 
-func (h *ephemeralTerminalUI) Teardown() error {
-	h.closeScreen()
+func (h *ephemeralTerminalUI) Teardown(force bool) error {
+	h.closeScreen(force)
 	ansi.CursorShow()
 	return nil
 }

internal/ui/logger_ui.go

@@ -33,6 +33,6 @@ func (l loggerUI) Handle(event partybus.Event) error {
 	return l.unsubscribe()
 }
 
-func (l loggerUI) Teardown() error {
+func (l loggerUI) Teardown(_ bool) error {
 	return nil
 }

internal/ui/ui.go

@@ -7,5 +7,5 @@ import (
 type UI interface {
 	Setup(unsubscribe func() error) error
 	partybus.Handler
-	Teardown() error
+	Teardown(force bool) error
 }