fix: Adds a message when new logs aren't shown to the user immediately (

#131)

* Adds a message when new logs aren't shown to the user immediately

packages/cli/internal/pkg/aws/cwl/stream_logs.go

@@ -38,6 +38,8 @@ func (c Client) StreamLogs(ctx context.Context, logGroupName string, streams ...
 			if aws.ToString(lastToken) != aws.ToString(output.NextToken) {
 				stream <- StreamEvent{Logs: parseEventLogs(output.Events, startTime)}
 				lastToken = output.NextToken
+			} else {
+				stream <- StreamEvent{}
 			}
 
 			select {

packages/cli/internal/pkg/aws/cwl/stream_logs_test.go

@@ -38,6 +38,22 @@ func TestClient_StreamLogs(t *testing.T) {
 	_, isOpen := <-stream
 	assert.False(t, isOpen)
 }
+func TestClient_StreamLogs_EmptyLog(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	client := NewMockClient()
+	client.cwl.(*CwlMock).On("FilterLogEvents", ctx, mock.Anything).
+		Return(&cloudwatchlogs.FilterLogEventsOutput{
+			NextToken: aws.String("Token"),
+			Events:    []types.FilteredLogEvent{}}, nil)
+	cancel()
+	stream := client.StreamLogs(ctx, testLogGroupName)
+	event := <-stream
+	assert.Equal(t, []string{}, event.Logs)
+	assert.NoError(t, event.Err)
+	cancel()
+	_, isOpen := <-stream
+	assert.False(t, isOpen)
+}
 
 func TestClient_StreamLogs_Error(t *testing.T) {
 	ctx := context.Background()

packages/cli/internal/pkg/cli/logs_core.go

@@ -42,6 +42,8 @@ Use a question mark for OR, such as "?ERROR ?WARN". Filter out terms with a minu
 	tailFlagDescription = "Follow the log output."
 )
 
+var logInfo = log.Info
+
 var printLn = func(args ...interface{}) {
 	_, _ = fmt.Println(args...)
 }
@@ -124,6 +126,8 @@ func (o *logsSharedOpts) followLogGroup(logGroupName string) error {
 }
 
 func (o *logsSharedOpts) displayEventFromChannel(channel <-chan cwl.StreamEvent) error {
+	firstEvent := true
+
 	for event := range channel {
 		if event.Err != nil {
 			return event.Err
@@ -132,10 +136,15 @@ func (o *logsSharedOpts) displayEventFromChannel(channel <-chan cwl.StreamEvent)
 			for _, line := range event.Logs {
 				printLn(line)
 			}
+		} else if firstEvent {
+			logInfo().Msg("There are no new logs. Please wait for the first logs to appear...")
 		} else {
 			log.Debug().Msg("No new logs")
 		}
+
+		firstEvent = false
 	}
+
 	return nil
 }
 

packages/cli/internal/pkg/cli/logs_core_test.go

@@ -6,6 +6,9 @@ import (
 	"time"
 
 	"github.com/aws/amazon-genomics-cli/internal/pkg/aws/cwl"
+	awsmocks "github.com/aws/amazon-genomics-cli/internal/pkg/mocks/aws"
+	iomocks "github.com/aws/amazon-genomics-cli/internal/pkg/mocks/io"
+	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -95,3 +98,47 @@ func Test_fanInChannels_nominal(t *testing.T) {
 	expected := []string{"foo1", "bar1", "foo2", "bar2", "something else", "singleton3"}
 	assert.ElementsMatch(t, actual, expected)
 }
+
+func Test_displayEventFromChannel_noLogs_showsWaitingMessage(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	cwlMock := awsmocks.NewMockCwlClient(ctrl)
+	mockLogs := iomocks.NewMockLog(ctrl)
+	orig := logInfo
+	logInfo = mockLogs.Info
+
+	mockLogs.EXPECT().Info().Times(1)
+
+	opts := logsAccessOpts{
+		logsSharedOpts: logsSharedOpts{cwlClient: cwlMock},
+		logsAccessVars: logsAccessVars{logsSharedVars{contextName: testContextName1}},
+	}
+	channel := make(chan cwl.StreamEvent)
+	go func() {
+		channel <- cwl.StreamEvent{Logs: []string{}}
+		close(channel)
+	}()
+	_ = opts.displayEventFromChannel(channel)
+	logInfo = orig
+}
+
+func Test_displayEventFromChannel_oneLog_OnlyShowsMessageFromChannel(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	cwlMock := awsmocks.NewMockCwlClient(ctrl)
+	mockFmt := iomocks.NewMockFormat(ctrl)
+	orig := printLn
+	printLn = mockFmt.LogsPrintLn
+
+	mockFmt.EXPECT().LogsPrintLn("hi").Return().Times(1)
+
+	opts := logsAccessOpts{
+		logsSharedOpts: logsSharedOpts{cwlClient: cwlMock},
+		logsAccessVars: logsAccessVars{logsSharedVars{contextName: testContextName1}},
+	}
+	channel := make(chan cwl.StreamEvent)
+	go func() {
+		channel <- cwl.StreamEvent{Logs: []string{"hi"}}
+		defer close(channel)
+	}()
+	_ = opts.displayEventFromChannel(channel)
+	printLn = orig
+}

packages/cli/internal/pkg/mocks/io/interfaces.go

@@ -1,6 +1,10 @@
 package iomocks
 
-import "io/fs"
+import (
+	"io/fs"
+
+	"github.com/rs/zerolog"
+)
 
 type OS interface {
 	Remove(name string) error
@@ -25,3 +29,11 @@ type FileReader interface {
 type FileWriter interface {
 	WriteFile(filename string, data []byte, perm fs.FileMode) error
 }
+
+type Format interface {
+	LogsPrintLn(args ...interface{})
+}
+
+type Log interface {
+	Info() *zerolog.Event
+}