fix: correct preOrderIndex and postOrderIndex

lib/buildChunkGraph.js

@@ -266,12 +266,18 @@ const visitModules = (
 	/** @type {Map<DependenciesBlock, ChunkGroupInfo>} */
 	const blockChunkGroups = new Map();
 
+	/** @type {Map<ChunkGroupInfo, DependenciesBlock>} */
+	const blockByChunkGroups = new Map();
+
 	/** @type {Map<string, ChunkGroupInfo>} */
 	const namedChunkGroups = new Map();
 
 	/** @type {Map<string, ChunkGroupInfo>} */
 	const namedAsyncEntrypoints = new Map();
 
+	/** @type {Set<ChunkGroupInfo>} */
+	const outdatedOrderIndexChunkGroups = new Set();
+
 	const ADD_AND_ENTER_ENTRY_MODULE = 0;
 	const ADD_AND_ENTER_MODULE = 1;
 	const ENTER_MODULE = 2;
@@ -524,6 +530,7 @@ const visitModules = (
 				blockConnections.set(b, []);
 			}
 			blockChunkGroups.set(b, /** @type {ChunkGroupInfo} */ (cgi));
+			blockByChunkGroups.set(cgi, b);
 		} else if (entryOptions) {
 			entrypoint = /** @type {Entrypoint} */ (cgi.chunkGroup);
 		} else {
@@ -1208,6 +1215,7 @@ const visitModules = (
 					chunkGroupsForCombining.add(cgi);
 				}
 			}
+			outdatedOrderIndexChunkGroups.add(info);
 		}
 		outdatedChunkGroupInfo.clear();
 	};
@@ -1254,6 +1262,51 @@ const visitModules = (
 		}
 	}
 
+	for (const info of outdatedOrderIndexChunkGroups) {
+		const { chunkGroup, runtime } = info;
+
+		const block = blockByChunkGroups.get(info);
+
+		if (!block) {
+			continue;
+		}
+
+		let preOrderIndex = 0;
+		let postOrderIndex = 0;
+
+		const process = (current, visited = new Set()) => {
+			if (visited.has(current)) {
+				return;
+			}
+
+			visited.add(current);
+
+			const blockModules = getBlockModules(current, runtime);
+			if (blockModules === undefined) {
+				return;
+			}
+
+			for (let i = 0; i < blockModules.length; i += 2) {
+				const refModule = /** @type {Module} */ (blockModules[i]);
+				const activeState = /** @type {ConnectionState} */ (
+					blockModules[i + 1]
+				);
+				if (activeState === false) {
+					continue;
+				}
+
+				if (refModule) {
+					chunkGroup.setModulePreOrderIndex(refModule, preOrderIndex++);
+					process(refModule, visited);
+					chunkGroup.setModulePostOrderIndex(refModule, postOrderIndex++);
+				}
+			}
+		};
+
+		process(block);
+	}
+	outdatedOrderIndexChunkGroups.clear();
+
 	logger.log(
 		`${statProcessedQueueItems} queue items processed (${statProcessedBlocks} blocks)`
 	);

test/configCases/chunk-index/issue-18008/A.js

@@ -0,0 +1,3 @@
+import './m.css'
+
+export default import(/* webpackChunkName: 'shared' */ './shared')

test/configCases/chunk-index/issue-18008/B-2.js

@@ -0,0 +1 @@
+export default import(/* webpackChunkName: 'shared' */ './shared')

test/configCases/chunk-index/issue-18008/B.js

@@ -0,0 +1 @@
+export default import(/* webpackChunkName: 'B-2' */ './B-2')

test/configCases/chunk-index/issue-18008/m.css

@@ -0,0 +1,3 @@
+.m {
+  color: red;
+}

test/configCases/chunk-index/issue-18008/main.js

@@ -0,0 +1,4 @@
+it('should compile', async () => {
+  await (await import(/* webpackChunkName: 'A' */ './A')).default
+  await (await import(/* webpackChunkName: 'B' */ './B')).default
+})

test/configCases/chunk-index/issue-18008/n.css

@@ -0,0 +1,3 @@
+.n {
+  color: red;
+}

test/configCases/chunk-index/issue-18008/shared.js

@@ -0,0 +1,2 @@
+import './m.css'
+import './n.css'

test/configCases/chunk-index/issue-18008/test.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+	findBundle: function (i, options) {
+		return ["main.js", "A.js", "shared.js", "B.js", "B-2.js"];
+	}
+};

test/configCases/chunk-index/issue-18008/webpack.config.js

@@ -0,0 +1,65 @@
+/** @typedef {import("../../../../types").Compilation} Compilation */
+/** @typedef {import("../../../../types").Module} Module */
+/** @type {import("../../../../types").Configuration} */
+module.exports = {
+	entry: {
+		main: "./main.js"
+	},
+	output: {
+		filename: "[name].js"
+	},
+	optimization: {
+		splitChunks: false,
+		chunkIds: "named"
+	},
+	plugins: [
+		function () {
+			/**
+			 * @param {Compilation} compilation compilation
+			 * @returns {void}
+			 */
+			const handler = compilation => {
+				compilation.hooks.afterSeal.tap("testcase", () => {
+					const data = {};
+					for (const [name, group] of compilation.namedChunkGroups) {
+						/** @type {Map<Module, number>} */
+						const modules = new Map();
+						for (const chunk of group.chunks) {
+							for (const module of compilation.chunkGraph.getChunkModulesIterable(
+								chunk
+							)) {
+								const preOrder = group.getModulePreOrderIndex(module);
+								if (typeof preOrder === "number") {
+									modules.set(module, preOrder);
+								}
+							}
+						}
+						const sortedModules = Array.from(modules).sort((a, b) => {
+							return a[1] - b[1];
+						});
+						const text = sortedModules
+							.map(
+								([m, index]) =>
+									`${index}: ${m.readableIdentifier(
+										compilation.requestShortener
+									)}`
+							)
+							.join(", ");
+						data[name + "Index"] = text;
+					}
+					expect(data).toEqual({
+						AIndex: "0: ./A.js, 1: css ./m.css",
+						"B-2Index": "0: ./B-2.js",
+						BIndex: "0: ./B.js",
+						mainIndex: "0: ./main.js",
+						sharedIndex: "0: ./shared.js, 1: css ./m.css, 2: css ./n.css"
+					});
+				});
+			};
+			this.hooks.compilation.tap("testcase", handler);
+		}
+	],
+	experiments: {
+		css: true
+	}
+};