Bug 1763823: pkg/payload/task_graph: Canceling the task graph partway though is an error even if no tasks fail

pkg/payload/task_graph.go

@@ -589,5 +589,9 @@ func RunGraph(ctx context.Context, graph *TaskGraph, maxParallelism int, fn func
 	if len(errs) > 0 {
 		return errs
 	}
+	// if the context was cancelled, we may have unfinished work
+	if err := ctx.Err(); err != nil {
+		return []error{err}
+	}
 	return nil
 }

pkg/payload/task_graph_test.go

@@ -609,12 +609,14 @@ func TestRunGraph(t *testing.T) {
 		wantErrs   []string
 	}{
 		{
+			name: "tasks executed in order",
 			nodes: []*TaskNode{
 				{Tasks: tasks("a", "b")},
 			},
 			order: []string{"a", "b"},
 		},
 		{
+			name: "nodes executed after dependencies",
 			nodes: []*TaskNode{
 				{Tasks: tasks("c"), In: []int{3}},
 				{Tasks: tasks("d", "e"), In: []int{3}},
@@ -644,6 +646,7 @@ func TestRunGraph(t *testing.T) {
 			},
 		},
 		{
+			name: "mid-task cancellation error interrupts node processing",
 			nodes: []*TaskNode{
 				{Tasks: tasks("c"), In: []int{2}},
 				{Tasks: tasks("d"), In: []int{2}, Out: []int{3}},
@@ -669,6 +672,7 @@ func TestRunGraph(t *testing.T) {
 			},
 		},
 		{
+			name: "task error interrupts node processing",
 			nodes: []*TaskNode{
 				{Tasks: tasks("c"), In: []int{2}},
 				{Tasks: tasks("d"), In: []int{2}, Out: []int{3}},
@@ -684,15 +688,15 @@ func TestRunGraph(t *testing.T) {
 					case <-time.After(time.Second):
 						t.Fatalf("expected context")
 					case <-ctx.Done():
-						t.Logf("got cancelled context")
-						return fmt.Errorf("cancelled")
+						t.Logf("got canceled context")
+						return ctx.Err()
 					}
 					return fmt.Errorf("error A")
 				}
 				return nil
 			},
 			want:     []string{"a", "b", "c"},
-			wantErrs: []string{"cancelled"},
+			wantErrs: []string{"context canceled"},
 			invariants: func(t *testing.T, got []string) {
 				for _, s := range got {
 					if s == "e" {
@@ -702,6 +706,7 @@ func TestRunGraph(t *testing.T) {
 			},
 		},
 		{
+			name: "task errors in parallel nodes both reported",
 			nodes: []*TaskNode{
 				{Tasks: tasks("a"), Out: []int{1}},
 				{Tasks: tasks("b"), In: []int{0}, Out: []int{2, 4, 8}},
@@ -727,6 +732,26 @@ func TestRunGraph(t *testing.T) {
 			want:     []string{"a", "b", "d1", "d2", "d3"},
 			wantErrs: []string{"error - c1", "error - f"},
 		},
+		{
+			name: "cancelation without task errors is reported",
+			nodes: []*TaskNode{
+				{Tasks: tasks("a"), Out: []int{1}},
+				{Tasks: tasks("b"), In: []int{0}},
+			},
+			sleep:    time.Millisecond,
+			parallel: 1,
+			errorOn: func(t *testing.T, name string, ctx context.Context, cancelFn func()) error {
+				if name == "a" {
+					cancelFn()
+					time.Sleep(time.Second)
+					return nil
+				}
+				t.Fatalf("task b should never run")
+				return nil
+			},
+			want:     []string{"a"},
+			wantErrs: []string{"context canceled"},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {