The event queue can now report if it is empty.

eventqueue/eventqueue.go

@@ -75,6 +75,13 @@ func (u *Unbound) wake() {
 	}
 }
 
+// Empty determines if the queue is empty.
+func (u *Unbound) Empty() bool {
+	u.mu.Lock()
+	defer u.mu.Unlock()
+	return u.empty()
+}
+
 // empty determines if the queue is empty.
 func (u *Unbound) empty() bool {
 	return u.first == nil

eventqueue/eventqueue_test.go

@@ -25,12 +25,14 @@ import (
 
 func TestQueue(t *testing.T) {
 	tests := []struct {
-		desc     string
-		pushes   []terminalapi.Event
-		wantPops []terminalapi.Event
+		desc      string
+		pushes    []terminalapi.Event
+		wantEmpty bool // Checked after pushes and before pops.
+		wantPops  []terminalapi.Event
 	}{
 		{
-			desc: "empty queue returns nil",
+			desc:      "empty queue returns nil",
+			wantEmpty: true,
 			wantPops: []terminalapi.Event{
 				nil,
 			},
@@ -42,6 +44,7 @@ func TestQueue(t *testing.T) {
 				terminalapi.NewError("error2"),
 				terminalapi.NewError("error3"),
 			},
+			wantEmpty: false,
 			wantPops: []terminalapi.Event{
 				terminalapi.NewError("error1"),
 				terminalapi.NewError("error2"),
@@ -59,6 +62,11 @@ func TestQueue(t *testing.T) {
 				q.Push(ev)
 			}
 
+			gotEmpty := q.Empty()
+			if gotEmpty != tc.wantEmpty {
+				t.Errorf("Empty => got %v, want %v", gotEmpty, tc.wantEmpty)
+			}
+
 			for i, want := range tc.wantPops {
 				got := q.Pop()
 				if diff := pretty.Compare(want, got); diff != "" {