bugfixes and optimizations

optimize name map for name equals id
bugfixes in named ids assigning
assign name before automatic ids

Author: sokra

lib/ids/IdHelpers.js

@@ -93,7 +93,6 @@ exports.getLongModuleName = getLongModuleName;
  * @returns {string} short chunk name
  */
 const getShortChunkName = (chunk, chunkGraph, context, delimiter) => {
-	if (chunk.name) return chunk.name;
 	const modules = chunkGraph.getChunkRootModules(chunk);
 	const shortModuleNames = modules.map(m =>
 		requestToId(getShortModuleName(m, context))
@@ -121,7 +120,6 @@ const getLongChunkName = (
 	requestShortener,
 	delimiter
 ) => {
-	if (chunk.name) return chunk.name;
 	const modules = chunkGraph.getChunkRootModules(chunk);
 	const shortModuleNames = modules.map(m =>
 		requestToId(getShortModuleName(m, context))
@@ -270,12 +268,15 @@ const assignNames = (
 			}
 		} else if (items.length === 1 && !usedIds.has(name)) {
 			assignName(items[0], name);
+			usedIds.add(name);
 		} else {
 			items.sort(comparator);
 			let i = 0;
 			for (const item of items) {
 				while (nameToItems2.has(name + i) && usedIds.has(name + i)) i++;
 				assignName(item, name + i);
+				usedIds.add(name + i);
+				i++;
 			}
 		}
 	}

lib/ids/NamedChunkIdsPlugin.js

@@ -41,6 +41,10 @@ class NamedChunkIdsPlugin {
 
 				const unnamedChunks = assignNames(
 					Array.from(chunks).filter(chunk => {
+						if (chunk.name) {
+							chunk.id = chunk.name;
+							chunk.ids = [chunk.name];
+						}
 						return chunk.id === null;
 					}),
 					chunk => getShortChunkName(chunk, chunkGraph, context, delimiter),
@@ -62,20 +66,6 @@ class NamedChunkIdsPlugin {
 				if (unnamedChunks.length > 0) {
 					assignAscendingChunkIds(unnamedChunks, compilation);
 				}
-
-				const usedIds = new Set();
-				if (compilation.usedChunkIds) {
-					for (const id of compilation.usedChunkIds) {
-						usedIds.add(id);
-					}
-				}
-
-				for (const chunk of chunks) {
-					const chunkId = chunk.id;
-					if (chunkId !== null) {
-						usedIds.add(chunkId);
-					}
-				}
 			});
 		});
 	}

lib/runtime/GetChunkFilenameRuntimeModule.js

@@ -8,6 +8,21 @@ const RuntimeGlobals = require("../RuntimeGlobals");
 const RuntimeModule = require("../RuntimeModule");
 const Template = require("../Template");
 
+const createChunkNameExpr = obj => {
+	const optimizedObj = {};
+	let hasEntries = false;
+	for (const key of Object.keys(obj)) {
+		const value = obj[key];
+		if (key !== value) {
+			optimizedObj[key] = value;
+			hasEntries = true;
+		}
+	}
+	return hasEntries
+		? `(${JSON.stringify(optimizedObj)}[chunkId]||chunkId)`
+		: "chunkId";
+};
+
 class GetChunkFilenameRuntimeModule extends RuntimeModule {
 	constructor(compilation, chunk, contentType, name, global, filename) {
 		super(`get ${name} chunk filename`);
@@ -44,7 +59,7 @@ class GetChunkFilenameRuntimeModule extends RuntimeModule {
 					}
 					return `" + ${JSON.stringify(shortChunkHashMap)}[chunkId] + "`;
 				},
-				name: `" + (${JSON.stringify(chunkMaps.name)}[chunkId]||chunkId) + "`,
+				name: `" + ${createChunkNameExpr(chunkMaps.name)} + "`,
 				contentHash: {
 					[contentType]: `" + ${JSON.stringify(
 						chunkMaps.contentHash[contentType]