Merge pull request #10344 from webpack/bugfix/hang-circular-reexport

fix hanging build when using circular export *

Author: sokra

lib/FlagDependencyExportsPlugin.js

@@ -7,11 +7,9 @@
 const Queue = require("./util/Queue");
 
 const addToSet = (a, b) => {
-	const size = a.size;
 	for (const item of b) {
 		a.add(item);
 	}
-	return a.size !== size;
 };
 
 class FlagDependencyExportsPlugin {
@@ -58,14 +56,11 @@ class FlagDependencyExportsPlugin {
 							// break if it should move to the worst state
 							if (exports === true) {
 								module.buildMeta.providedExports = true;
-								notifyDependencies();
 								return true;
 							}
 							// merge in new exports
 							if (Array.isArray(exports)) {
-								if (addToSet(moduleProvidedExports, exports)) {
-									notifyDependencies();
-								}
+								addToSet(moduleProvidedExports, exports);
 							}
 							// store dependencies
 							const exportDeps = exportDesc.dependencies;
@@ -93,6 +88,26 @@ class FlagDependencyExportsPlugin {
 							}
 						};
 
+						const notifyDependenciesIfDifferent = (set, array) => {
+							const deps = dependencies.get(module);
+							if (deps !== undefined) {
+								if (set.size === array.length) {
+									let i = 0;
+									let different = false;
+									for (const item of set) {
+										if (item !== array[i++]) {
+											different = true;
+											break;
+										}
+									}
+									if (!different) return;
+								}
+								for (const dep of deps) {
+									queue.enqueue(dep);
+								}
+							}
+						};
+
 						// Start with all modules without provided exports
 						for (const module of modules) {
 							if (module.buildInfo.temporaryProvidedExports) {
@@ -116,9 +131,20 @@ class FlagDependencyExportsPlugin {
 								processDependenciesBlock(module);
 								module.buildInfo.temporaryProvidedExports = providedExportsAreTemporary;
 								if (!moduleWithExports) {
+									notifyDependencies();
 									module.buildMeta.providedExports = true;
+								} else if (module.buildMeta.providedExports === true) {
+									notifyDependencies();
+								} else if (!module.buildMeta.providedExports) {
 									notifyDependencies();
-								} else if (module.buildMeta.providedExports !== true) {
+									module.buildMeta.providedExports = Array.from(
+										moduleProvidedExports
+									);
+								} else {
+									notifyDependenciesIfDifferent(
+										moduleProvidedExports,
+										module.buildMeta.providedExports
+									);
 									module.buildMeta.providedExports = Array.from(
 										moduleProvidedExports
 									);

lib/dependencies/HarmonyExportImportedSpecifierDependency.js

@@ -304,9 +304,13 @@ class HarmonyExportImportedSpecifierDependency extends HarmonyImportDependency {
 		}
 
 		if (Array.isArray(importedModule.buildMeta.providedExports)) {
+			const activeFromOtherStarExports = this._discoverActiveExportsFromOtherStartExports();
 			return {
 				exports: importedModule.buildMeta.providedExports.filter(
-					id => id !== "default"
+					id =>
+						id !== "default" &&
+						!activeFromOtherStarExports.has(id) &&
+						!this.activeExports.has(id)
 				),
 				dependencies: [importedModule]
 			};

test/cases/parsing/harmony-circular-star-reexport/a.js

@@ -0,0 +1,2 @@
+export * from "./c";
+export const a = "a";

test/cases/parsing/harmony-circular-star-reexport/b.js

@@ -0,0 +1,2 @@
+export * from "./a";
+export const b = "b";

test/cases/parsing/harmony-circular-star-reexport/c.js

@@ -0,0 +1,2 @@
+export * from "./b";
+export const c = "c";

test/cases/parsing/harmony-circular-star-reexport/index.js

@@ -0,0 +1,11 @@
+import * as all from "./c";
+
+it("should contain all exports", () => {
+	expect(all).toEqual(
+		nsObj({
+			a: "a",
+			b: "b",
+			c: "c"
+		})
+	);
+});