allow to mangle exports of module externals

webpack · Sep 3, 2021 · b50d033 · b50d033
1 parent 4e8a621
commit b50d033
Showing 1 changed file with 21 additions and 4 deletions.
diff --git a/lib/optimize/MangleExportsPlugin.js b/lib/optimize/MangleExportsPlugin.js
@@ -39,13 +39,28 @@ const comparator = compareSelect(e => e.name, compareStringsNumeric);
 /**
  * @param {boolean} deterministic use deterministic names
  * @param {ExportsInfo} exportsInfo exports info
+ * @param {boolean} isNamespace is namespace object
  * @returns {void}
  */
-const mangleExportsInfo = (deterministic, exportsInfo) => {
+const mangleExportsInfo = (deterministic, exportsInfo, isNamespace) => {
 	if (!canMangle(exportsInfo)) return;
 	const usedNames = new Set();
 	/** @type {ExportInfo[]} */
 	const mangleableExports = [];
+
+	// Avoid to renamed exports that are not provided when
+	// 1. it's not a namespace export: non-provided exports can be found in prototype chain
+	// 2. there are other provided exports and deterministic mode is chosen:
+	//    non-provided exports would break the determinism
+	let avoidMangleNonProvided = !isNamespace;
+	if (!avoidMangleNonProvided && deterministic) {
+		for (const exportInfo of exportsInfo.ownedExports) {
+			if (exportInfo.provided !== false) {
+				avoidMangleNonProvided = true;
+				break;
+			}
+		}
+	}
 	for (const exportInfo of exportsInfo.ownedExports) {
 		const name = exportInfo.name;
 		if (!exportInfo.hasUsedName()) {
@@ -59,7 +74,7 @@ const mangleExportsInfo = (deterministic, exportsInfo) => {
 					name.length === 2 &&
 					/^[a-zA-Z_$][a-zA-Z0-9_$]|^[1-9][0-9]/.test(name)) ||
 				// Don't rename exports that are not provided
-				exportInfo.provided !== true
+				(avoidMangleNonProvided && exportInfo.provided !== true)
 			) {
 				exportInfo.setUsedName(name);
 				usedNames.add(name);
@@ -73,7 +88,7 @@ const mangleExportsInfo = (deterministic, exportsInfo) => {
 				used === UsageState.OnlyPropertiesUsed ||
 				used === UsageState.Unused
 			) {
-				mangleExportsInfo(deterministic, exportInfo.exportsInfo);
+				mangleExportsInfo(deterministic, exportInfo.exportsInfo, false);
 			}
 		}
 	}
@@ -143,8 +158,10 @@ class MangleExportsPlugin {
 				"MangleExportsPlugin",
 				modules => {
 					for (const module of modules) {
+						const isNamespace =
+							module.buildMeta && module.buildMeta.exportsType === "namespace";
 						const exportsInfo = moduleGraph.getExportsInfo(module);
-						mangleExportsInfo(deterministic, exportsInfo);
+						mangleExportsInfo(deterministic, exportsInfo, isNamespace);
 					}
 				}
 			);