Use acorn@5

lib/Parser.js

@@ -988,20 +988,16 @@ class Parser extends Tapable {
 			this.hooks.export.call(statement);
 		}
 		if(statement.declaration) {
-			if(/Expression$/.test(statement.declaration.type)) {
+			if(!this.hooks.exportDeclaration.call(statement, statement.declaration)) {
-				throw new Error("Doesn't occur?");
+				const originalDefinitions = this.scope.definitions;
-			} else {
+				const tracker = new TrackingSet(this.scope.definitions);
-				if(!this.hooks.exportDeclaration.call(statement, statement.declaration)) {
+				this.scope.definitions = tracker;
-					const originalDefinitions = this.scope.definitions;
+				this.prewalkStatement(statement.declaration);
-					const tracker = new TrackingSet(this.scope.definitions);
+				const newDefs = Array.from(tracker.getAddedItems());
-					this.scope.definitions = tracker;
+				this.scope.definitions = originalDefinitions;
-					this.prewalkStatement(statement.declaration);
+				for(let index = newDefs.length - 1; index >= 0; index--) {
-					const newDefs = Array.from(tracker.getAddedItems());
+					const def = newDefs[index];
-					this.scope.definitions = originalDefinitions;
+					this.hooks.exportSpecifier.call(statement, def, def, index);
-					for(let index = newDefs.length - 1; index >= 0; index--) {
-						const def = newDefs[index];
-						this.hooks.exportSpecifier.call(statement, def, def, index);
-					}
 				}
 			}
 		}
@@ -1030,7 +1026,7 @@ class Parser extends Tapable {
 	}
 
 	prewalkExportDefaultDeclaration(statement) {
-		if(/Declaration$/.test(statement.declaration.type)) {
+		if(statement.declaration.id) {
 			const originalDefinitions = this.scope.definitions;
 			const tracker = new TrackingSet(this.scope.definitions);
 			this.scope.definitions = tracker;
@@ -1046,12 +1042,21 @@ class Parser extends Tapable {
 
 	walkExportDefaultDeclaration(statement) {
 		this.hooks.export.call(statement);
-		if(/Declaration$/.test(statement.declaration.type)) {
+		if(statement.declaration.id) {
 			if(!this.hooks.exportDeclaration.call(statement, statement.declaration)) {
 				this.walkStatement(statement.declaration);
 			}
 		} else {
-			this.walkExpression(statement.declaration);
+			// Acorn parses `export default function() {}` as `FunctionDeclaration` and
+			// `export default class {}` as `ClassDeclaration`, both with `id = null`.
+			// These nodes must be treated as expressions.
+			if(statement.declaration.type === "FunctionDeclaration") {
+				this.walkFunctionDeclaration(statement.declaration);
+			} else if(statement.declaration.type === "ClassDeclaration") {
+				this.walkClassDeclaration(statement.declaration);
+			} else {
+				this.walkExpression(statement.declaration);
+			}
 			if(!this.hooks.exportExpression.call(statement, statement.declaration)) {
 				this.hooks.exportSpecifier.call(statement, statement.declaration, "default");
 			}

package.json

@@ -3,9 +3,10 @@
   "version": "4.0.0-alpha.4",
   "author": "Tobias Koppers @sokra",
   "description": "Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.",
+  "license": "MIT",
   "dependencies": {
     "acorn": "^5.0.0",
-    "acorn-dynamic-import": "^2.0.0",
+    "acorn-dynamic-import": "^3.0.0",
     "ajv": "^5.1.5",
     "ajv-keywords": "^2.0.0",
     "async": "^2.1.2",
@@ -22,7 +23,6 @@
     "watchpack": "^1.4.0",
     "webpack-sources": "^1.0.1"
   },
-  "license": "MIT",
   "devDependencies": {
     "beautify-lint": "^1.0.3",
     "benchmark": "^2.1.1",

yarn.lock

@@ -17,11 +17,11 @@ accepts@~1.2.12:
     mime-types "~2.1.6"
     negotiator "0.5.3"
 
-acorn-dynamic-import@^2.0.0:
+acorn-dynamic-import@^3.0.0:
-  version "2.0.2"
+  version "3.0.0"
-  resolved "https://registry.yarnpkg.com/acorn-dynamic-import/-/acorn-dynamic-import-2.0.2.tgz#c752bd210bef679501b6c6cb7fc84f8f47158cc4"
+  resolved "https://registry.yarnpkg.com/acorn-dynamic-import/-/acorn-dynamic-import-3.0.0.tgz#901ceee4c7faaef7e07ad2a47e890675da50a278"
   dependencies:
-    acorn "^4.0.3"
+    acorn "^5.0.0"
 
 acorn-globals@^1.0.3:
   version "1.0.9"
@@ -47,10 +47,6 @@ acorn@^3.0.4:
   version "3.3.0"
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-3.3.0.tgz#45e37fb39e8da3f25baee3ff5369e2bb5f22017a"
 
-acorn@^4.0.3:
-  version "4.0.13"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-4.0.13.tgz#105495ae5361d697bd195c825192e1ad7f253787"
-
 acorn@^5.0.0, acorn@^5.2.1:
   version "5.3.0"
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.3.0.tgz#7446d39459c54fb49a80e6ee6478149b940ec822"