Close cross-cutting sequence regression gaps

internal/engine/destination_accounting_test.go

@@ -68,6 +68,66 @@ func TestMultipleMountedInputsSharePlacementCharges(t *testing.T) {
 	}
 }
 
+func TestNestedItemGlobsShareUnderlayNodeBudget(t *testing.T) {
+	t.Parallel()
+
+	directory := t.TempDir()
+	mainPath := writeImportFile(t, directory, "main.yml", `configkit:
+  imports:
+    - glob: children/*.yml
+      destination: [children]
+      placement: sequence-item
+id: parent
+`)
+	fragmentPath := writeImportFile(t, directory, "children/a.yml", "id: child-a\n")
+	parseNodes := func(path string) int {
+		t.Helper()
+		parsed, diagnostics := parseSource(File(path), "fixture", defaultParseLimits())
+		if len(diagnostics) != 0 {
+			t.Fatalf("parse %s: %#v", path, diagnostics)
+		}
+		return countInputNodes(parsed.document)
+	}
+	destination := Keys("groups")
+	childDestination := appendDestination(destination, Keys("children"))
+	otherDestination := Keys("other")
+	wantNodes := parseNodes(mainPath) + parseNodes(fragmentPath) + countInputNodes(&document.Node{Kind: document.Mapping}) +
+		destinationWrapperNodeCountForMode(destination, placementModeSequenceItem) +
+		destinationWrapperNodeCountForMode(childDestination, placementModeSequenceItem) +
+		destinationWrapperNodeCountForMode(otherDestination, placementModeSequenceItem)
+	limits := defaultImportLimits()
+
+	for _, test := range []struct {
+		name      string
+		delta     int
+		wantError bool
+	}{
+		{name: "at aggregate bound"},
+		{name: "one node below aggregate bound", delta: 1, wantError: true},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			accounting := &importAccounting{nodes: limits.nodes - wantNodes + test.delta}
+			composition, sources, _, diagnostics := acquireUnderlayGroup(loadGroup{inputs: []loadInput{{
+				source: File(mainPath), imports: true, destination: destination, placementMode: placementModeSequenceItem,
+			}, {
+				source: Mapping("other", map[string]any{"id": "other"}), destination: otherDestination, placementMode: placementModeSequenceItem,
+			}}}, 1, nil, accounting)
+			if test.wantError {
+				if composition != nil || len(diagnostics) == 0 || diagnostics[0].Code != CodeSourceLimitExceeded {
+					t.Fatalf("under-budget nested item glob = %#v, %#v", composition, diagnostics)
+				}
+				return
+			}
+			if composition == nil || len(diagnostics) != 0 || len(sources) != 3 {
+				t.Fatalf("bounded nested item glob = %#v, sources %#v, diagnostics %#v", composition, sources, diagnostics)
+			}
+			if composition.inputNodes != wantNodes || accounting.nodes != limits.nodes+test.delta {
+				t.Fatalf("nested item node charge = %d/%d, want %d/%d", composition.inputNodes, accounting.nodes, wantNodes, limits.nodes+test.delta)
+			}
+		})
+	}
+}
+
 func TestImportedEmptyBodiesChargeEachDestinationWrapper(t *testing.T) {
 	t.Parallel()