fix: stop polling activity logs after an auth error

internal/pkg/platform/activity.go

@@ -108,9 +108,13 @@ func Activity(
 			// Try to grab new logs using the last logs timestamp
 			activityRequest.MinimumDateCreated = latestCreatedTimestamp + 1
 
-			// Avoid exit on error from the activity API when tailing logs
+			// Avoid exit on error from the activity API when tailing logs, unless
+			// the token can no longer be used and every later request would fail
 			newLatestCreatedTimestamp, count, err := printLatestActivity(ctx, clients, token, activityRequest, token)
 			if err != nil {
+				if isAuthError(err) {
+					return err
+				}
 				clients.IO.PrintDebug(ctx, "%s\n", err)
 			}
 
@@ -132,6 +136,18 @@ func Activity(
 	}
 }
 
+// isAuthError returns true if the error means the token is no longer valid
+func isAuthError(err error) bool {
+	switch slackerror.ToSlackError(err).Code {
+	case slackerror.ErrInvalidAuth,
+		slackerror.ErrNotAuthed,
+		slackerror.ErrTokenExpired,
+		slackerror.ErrTokenRevoked:
+		return true
+	}
+	return false
+}
+
 func printLatestActivity(ctx context.Context, clients *shared.ClientFactory, token string, args types.ActivityRequest, xoxpToken string) (latestCreated int64, num int, e error) {
 	var span opentracing.Span
 	span, ctx = opentracing.StartSpanFromContext(ctx, "getLatestActivity")

internal/pkg/platform/activity_test.go

@@ -246,6 +246,27 @@ func TestPlatformActivity_StreamingLogs(t *testing.T) {
 				cm.API.AssertNumberOfCalls(t, "Activity", 1)
 			},
 		},
+		"should return error if TailArg is set and activity request fails with an auth error while polling": {
+			Args: types.ActivityArgs{
+				TailArg:           true,
+				IdleTimeoutM:      1,
+				PollingIntervalMS: 20, // poll activity every 20 ms
+			},
+			Setup: func(t *testing.T, ctx context.Context, cm *shared.ClientsMock) context.Context {
+				cm.API.On("Activity", mock.Anything, mock.Anything, mock.Anything).Return(api.ActivityResult{}, slackerror.New(slackerror.ErrTokenRevoked))
+				ctx, cancel := context.WithCancel(ctx)
+				go func() {
+					time.Sleep(time.Millisecond * 50) // cancel activity in 50 ms
+					cancel()
+				}()
+				return ctx
+			},
+			ExpectedError: slackerror.New(slackerror.ErrTokenRevoked),
+			ExpectedAsserts: func(t *testing.T, ctx context.Context, cm *shared.ClientsMock) {
+				// the initial request and the first polling request, then polling stops
+				cm.API.AssertNumberOfCalls(t, "Activity", 2)
+			},
+		},
 		"should return nil if TailArg is set and activity request fails while polling": {
 			Args: types.ActivityArgs{
 				TailArg:           true,
@@ -909,6 +930,25 @@ func Test_functionExecutionStartedToString(t *testing.T) {
 	assert.Contains(t, result, "Trace=trace1")
 }
 
+func Test_isAuthError(t *testing.T) {
+	tests := map[string]struct {
+		err      error
+		expected bool
+	}{
+		"invalid auth":   {err: slackerror.New(slackerror.ErrInvalidAuth), expected: true},
+		"not authed":     {err: slackerror.New(slackerror.ErrNotAuthed), expected: true},
+		"token expired":  {err: slackerror.New(slackerror.ErrTokenExpired), expected: true},
+		"token revoked":  {err: slackerror.New(slackerror.ErrTokenRevoked), expected: true},
+		"internal error": {err: slackerror.New(slackerror.ErrInternal), expected: false},
+		"unknown error":  {err: slackerror.New("mock_broken_logs"), expected: false},
+	}
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			assert.Equal(t, tc.expected, isAuthError(tc.err))
+		})
+	}
+}
+
 func Test_triggerPayloadReceivedOutputToString(t *testing.T) {
 	activity := api.Activity{
 		Level:       types.INFO,