perf: cache module.modules

Author: SyMind

packages/rspack/src/ChunkGroup.ts

@@ -15,6 +15,7 @@ export class ChunkGroup {
 
 	#inner: JsChunkGroup;
 
+	#chunks = new VolatileValue<ReadonlyArray<Chunk>>();
 	#name = new VolatileValue<string | undefined>();
 
 	static __from_binding(binding: JsChunkGroup) {
@@ -34,9 +35,14 @@ export class ChunkGroup {
 			chunks: {
 				enumerable: true,
 				get: () => {
-					return this.#inner.chunks.map(binding =>
+					if (this.#chunks.has()) {
+						return this.#chunks.get();
+					}
+					const chunks = this.#inner.chunks.map(binding =>
 						Chunk.__from_binding(binding)
 					);
+					this.#chunks.set(chunks);
+					return chunks;
 				}
 			},
 			index: {

packages/rspack/src/Module.ts

@@ -211,6 +211,7 @@ export class Module {
 	#rawRequest: string | undefined | null;
 	#resourceResolveData: ResolveData | undefined | null;
 	#matchResource: string | undefined | null;
+	#modules: Module[] | undefined | null;
 
 	declare readonly context: string | null;
 	declare readonly resource: string | null;
@@ -341,13 +342,17 @@ export class Module {
 			},
 			modules: {
 				enumerable: true,
-				get(): Module[] | undefined {
+				get: (): Module[] | null => {
 					if (module instanceof JsModule) {
-						return module.modules
+						if (this.#modules !== undefined) {
+							return this.#modules;
+						}
+						this.#modules = module.modules
 							? module.modules.map(m => Module.__from_binding(m))
-							: undefined;
+							: null;
+						return this.#modules;
 					}
-					return undefined;
+					return null;
 				}
 			},
 			blocks: {