service/dap: send 'continued' event on next/step/stepout requests (#2480)

* service/dap: send 'continued' event on next/step/stepout requests

Next/step/stepout requests assume that execution is only resumed
on the thread that was specified. We cannot resume execution on
only a single thread, so we need to send a continued event to let
the client know that all threads have resumed.

* update set breakpoints test with continued event

service/dap/server.go

@@ -1254,6 +1254,15 @@ func stoppedGoroutineID(state *api.DebuggerState) (id int) {
 // due to an error, so the server is ready to receive new requests.
 func (s *Server) doStepCommand(command string, threadId int, asyncSetupDone chan struct{}) {
 	defer s.asyncCommandDone(asyncSetupDone)
+	// All of the threads will be continued by this request, so we need to send
+	// a continued event so the UI can properly reflect the current state.
+	s.send(&dap.ContinuedEvent{
+		Event: *newEvent("continued"),
+		Body: dap.ContinuedEventBody{
+			ThreadId:            threadId,
+			AllThreadsContinued: true,
+		},
+	})
 	_, err := s.debugger.Command(&api.DebuggerCommand{Name: api.SwitchGoroutine, GoroutineID: threadId}, nil)
 	if err != nil {
 		s.log.Errorf("Error switching goroutines while stepping: %v", err)

service/dap/server_test.go

@@ -1701,6 +1701,7 @@ func TestVariablesLoading(t *testing.T) {
 					// step into another function
 					client.StepInRequest(1)
 					client.ExpectStepInResponse(t)
+					client.ExpectContinuedEvent(t)
 					client.ExpectStoppedEvent(t)
 					handleStop(t, client, 1, "main.barfoo", 24)
 					loadvars(1001 /*second frame here is same as topmost above*/)
@@ -1748,6 +1749,7 @@ func TestGlobalScopeAndVariables(t *testing.T) {
 					// Step into pkg.AnotherMethod()
 					client.StepInRequest(1)
 					client.ExpectStepInResponse(t)
+					client.ExpectContinuedEvent(t)
 					client.ExpectStoppedEvent(t)
 
 					client.StackTraceRequest(1, 0, 20)
@@ -1981,6 +1983,7 @@ func TestSetBreakpointWhileRunning(t *testing.T) {
 					// We can set breakpoints while nexting
 					client.NextRequest(1)
 					client.ExpectNextResponse(t)
+					client.ExpectContinuedEvent(t)
 					client.SetBreakpointsRequest(fixture.Source, []int{15}) // [16,] => [15,]
 					se, br := expectSetBreakpointsResponseAndStoppedEvent(t, client)
 					if se.Body.Reason != "pause" || !se.Body.AllThreadsStopped || se.Body.ThreadId != 0 && se.Body.ThreadId != 1 {
@@ -2479,18 +2482,22 @@ func TestNextAndStep(t *testing.T) {
 
 					client.StepOutRequest(1)
 					client.ExpectStepOutResponse(t)
+					client.ExpectContinuedEvent(t)
 					expectStop("main.main", 18)
 
 					client.NextRequest(1)
 					client.ExpectNextResponse(t)
+					client.ExpectContinuedEvent(t)
 					expectStop("main.main", 19)
 
 					client.StepInRequest(1)
 					client.ExpectStepInResponse(t)
+					client.ExpectContinuedEvent(t)
 					expectStop("main.inlineThis", 5)
 
 					client.NextRequest(-1000)
 					client.ExpectNextResponse(t)
+					client.ExpectContinuedEvent(t)
 					if se := client.ExpectStoppedEvent(t); se.Body.Reason != "error" || se.Body.Text != "unknown goroutine -1000" {
 						t.Errorf("got %#v, want Reaspon=\"error\", Text=\"unknown goroutine -1000\"", se)
 					}
@@ -2519,6 +2526,7 @@ func TestNextParked(t *testing.T) {
 
 					client.NextRequest(goroutineId)
 					client.ExpectNextResponse(t)
+					client.ExpectContinuedEvent(t)
 
 					se := client.ExpectStoppedEvent(t)
 					if se.Body.ThreadId != goroutineId {
@@ -2548,6 +2556,7 @@ func TestStepInParked(t *testing.T) {
 
 					client.StepInRequest(goroutineId)
 					client.ExpectStepInResponse(t)
+					client.ExpectContinuedEvent(t)
 
 					se := client.ExpectStoppedEvent(t)
 					if se.Body.ThreadId != goroutineId {
@@ -2667,6 +2676,7 @@ func TestStepOutPreservesGoroutine(t *testing.T) {
 					}
 					client.StepOutRequest(goroutineId)
 					client.ExpectStepOutResponse(t)
+					client.ExpectContinuedEvent(t)
 
 					switch e := client.ExpectMessage(t).(type) {
 					case *dap.StoppedEvent:
@@ -2720,18 +2730,22 @@ func TestBadAccess(t *testing.T) {
 
 					client.NextRequest(1)
 					client.ExpectNextResponse(t)
+					client.ExpectContinuedEvent(t)
 					expectStoppedOnError("invalid memory address or nil pointer dereference")
 
 					client.NextRequest(1)
 					client.ExpectNextResponse(t)
+					client.ExpectContinuedEvent(t)
 					expectStoppedOnError("next while nexting")
 
 					client.StepInRequest(1)
 					client.ExpectStepInResponse(t)
+					client.ExpectContinuedEvent(t)
 					expectStoppedOnError("next while nexting")
 
 					client.StepOutRequest(1)
 					client.ExpectStepOutResponse(t)
+					client.ExpectContinuedEvent(t)
 					expectStoppedOnError("next while nexting")
 				},
 				disconnect: true,
@@ -2792,6 +2806,7 @@ func TestPanicBreakpointOnNext(t *testing.T) {
 
 					client.NextRequest(1)
 					client.ExpectNextResponse(t)
+					client.ExpectContinuedEvent(t)
 
 					se := client.ExpectStoppedEvent(t)
 					if se.Body.ThreadId != 1 || se.Body.Reason != "exception" || se.Body.Description != "Paused on panic" {