perf: skip collecting guard when exports presence mode is none (#20433)

hai-x · web-flow · commit 43903e13a822 · 2026-02-10T16:43:00.000+03:00
diff --git a/.changeset/lazy-ideas-flow.md b/.changeset/lazy-ideas-flow.md
@@ -0,0 +1,5 @@
+---
+"webpack": patch
+---
+
+Revert part of the createRequire generation behavior for `require("node:...")` to keep compatibility with those modules exports, e.g. `const EventEmitter = require("node:events");`.
diff --git a/.changeset/silver-plants-sell.md b/.changeset/silver-plants-sell.md
@@ -0,0 +1,5 @@
+---
+"webpack": patch
+---
+
+Skip guard collection when exports-presence mode is disabled to improve parsing performance.
diff --git a/lib/dependencies/HarmonyEvaluatedImportSpecifierDependency.js b/lib/dependencies/HarmonyEvaluatedImportSpecifierDependency.js
@@ -6,6 +6,7 @@
 "use strict";
 
 const makeSerializable = require("../util/makeSerializable");
+const { ExportPresenceModes } = require("./HarmonyImportDependency");
 const HarmonyImportSpecifierDependency = require("./HarmonyImportSpecifierDependency");
 const { ImportPhase } = require("./ImportPhase");
 
@@ -44,7 +45,7 @@ class HarmonyEvaluatedImportSpecifierDependency extends HarmonyImportSpecifierDe
 			ids,
 			name,
 			range,
-			false,
+			ExportPresenceModes.NONE,
 			ImportPhase.Evaluation,
 			attributes,
 			[]
diff --git a/lib/dependencies/HarmonyImportDependency.js b/lib/dependencies/HarmonyImportDependency.js
@@ -29,7 +29,7 @@ const ModuleDependency = require("./ModuleDependency");
 /** @typedef {import("../serialization/ObjectMiddleware").ObjectSerializerContext} ObjectSerializerContext */
 /** @typedef {import("../util/runtime").RuntimeSpec} RuntimeSpec */
 
-/** @typedef {0 | 1 | 2 | 3 | false} ExportPresenceMode */
+/** @typedef {0 | 1 | 2 | 3} ExportPresenceMode */
 
 const ExportPresenceModes = {
 	NONE: /** @type {ExportPresenceMode} */ (0),
diff --git a/lib/dependencies/HarmonyImportDependencyParserPlugin.js b/lib/dependencies/HarmonyImportDependencyParserPlugin.js
@@ -81,6 +81,7 @@ module.exports = class HarmonyImportDependencyParserPlugin {
 	 */
 	constructor(options) {
 		this.options = options;
+		/** @type {ExportPresenceMode} */
 		this.exportPresenceMode =
 			options.importExportsPresence !== undefined
 				? ExportPresenceModes.fromUserOption(options.importExportsPresence)
@@ -107,7 +108,7 @@ module.exports = class HarmonyImportDependencyParserPlugin {
 			parser.getTagData(harmonySettings.name, harmonySpecifierGuardTag)
 		);
 		return data && data.guards && data.guards.has(getMembersKey(ids))
-			? false
+			? ExportPresenceModes.NONE
 			: this.exportPresenceMode;
 	}
 
@@ -651,17 +652,19 @@ module.exports = class HarmonyImportDependencyParserPlugin {
 			}
 		};
 
-		parser.hooks.collectGuards.tap(PLUGIN_NAME, (expression) => {
-			if (parser.scope.isAsmJs) return;
-			/** @type {Guards} */
-			const guards = new Map();
-			collect(expression, guards, true);
+		if (this.exportPresenceMode !== ExportPresenceModes.NONE) {
+			parser.hooks.collectGuards.tap(PLUGIN_NAME, (expression) => {
+				if (parser.scope.isAsmJs) return;
+				/** @type {Guards} */
+				const guards = new Map();
+				collect(expression, guards, true);
 
-			if (guards.size === 0) return;
-			return (walk) => {
-				withGuards(guards, walk);
-			};
-		});
+				if (guards.size === 0) return;
+				return (walk) => {
+					withGuards(guards, walk);
+				};
+			});
+		}
 	}
 };
 
diff --git a/types.d.ts b/types.d.ts
@@ -5304,7 +5304,7 @@ type ExportModeType =
 	| "reexport-undefined"
 	| "normal-reexport"
 	| "dynamic-reexport";
-type ExportPresenceMode = false | 0 | 1 | 2 | 3;
+type ExportPresenceMode = 0 | 1 | 2 | 3;
 declare interface ExportSpec {
 	/**
 	 * the name of the export

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +"webpack": patch
 +---
++
 +Revert part of the createRequire generation behavior for `require("node:...")` to keep compatibility with those modules exports, e.g. `const EventEmitter = require("node:events");`.