Schedule sibling inheritance by dependency readiness

internal/engine/inheritance_schedule_test.go

@@ -110,6 +110,41 @@ beta:
 	}
 }
 
+func TestInheritanceExpansionInterleavesUnequalBranches(t *testing.T) {
+	root := parseCompositionDocument(t, "branches", `a-grandchild:
+  extends: z-child
+  own: grandchild
+b-base:
+  base: b
+c-base:
+  base: c
+d-child:
+  extends: c-base
+  own: d
+z-child:
+  extends: b-base
+  own: z
+`)
+	result, diagnostics := expandInheritanceTree(root, defaultProjectionLimits())
+	if len(diagnostics) != 0 {
+		t.Fatalf("expand diagnostics = %#v", diagnostics)
+	}
+	got := make([]string, len(result.transfers))
+	for i, transfer := range result.transfers {
+		got[i] = transfer.from.String() + " -> " + transfer.to.String()
+	}
+	want := []string{"/c-base -> /d-child", "/b-base -> /z-child", "/z-child -> /a-grandchild"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("transfer order = %v, want %v", got, want)
+	}
+	if value, found := documentAtPath(result.root, Path{}.Key("a-grandchild").Key("base")); !found || value.Text != "b" {
+		t.Fatalf("grandchild inherited value = %#v, found %t", value, found)
+	}
+	if value, found := documentAtPath(result.root, Path{}.Key("d-child").Key("base")); !found || value.Text != "c" {
+		t.Fatalf("independent branch inherited value = %#v, found %t", value, found)
+	}
+}
+
 func TestInheritanceGraphValidatesRelationshipKinds(t *testing.T) {
 	tests := []struct {
 		name string