From a167a7ecf557614d691dfaceec36947a8c723242 Mon Sep 17 00:00:00 2001
From: Tobias Koppers <tobias.koppers@googlemail.com>
Date: Fri, 21 Jul 2017 23:32:31 +0200
Subject: [PATCH] allow to use default export of root module in concatenated
 module in inner modules better error messages when parsing fails

fixes #5314
#5304
---
 lib/optimize/ConcatenatedModule.js            | 43 ++++++++++++-------
 test/cases/scope-hoisting/issue-5314/index.js |  9 ++++
 .../cases/scope-hoisting/issue-5314/module.js |  2 +
 3 files changed, 38 insertions(+), 16 deletions(-)
 create mode 100644 test/cases/scope-hoisting/issue-5314/index.js
 create mode 100644 test/cases/scope-hoisting/issue-5314/module.js

diff --git a/lib/optimize/ConcatenatedModule.js b/lib/optimize/ConcatenatedModule.js
index ff59f117075..ef74f1eec8c 100644
--- a/lib/optimize/ConcatenatedModule.js
+++ b/lib/optimize/ConcatenatedModule.js
@@ -309,12 +309,22 @@ class ConcatenatedModule extends Module {
 			const m = info.module;
 			const source = m.source(innerDependencyTemplates, outputOptions, requestShortener);
 			const code = source.source();
-			const ast = acorn.parse(code, {
-				ranges: true,
-				locations: true,
-				ecmaVersion: Parser.ECMA_VERSION,
-				sourceType: "module"
-			});
+			let ast;
+			try {
+				ast = acorn.parse(code, {
+					ranges: true,
+					locations: true,
+					ecmaVersion: Parser.ECMA_VERSION,
+					sourceType: "module"
+				});
+			} catch(err) {
+				if(err.loc && typeof err.loc === "object" && typeof err.loc.line === "number") {
+					const lineNumber = err.loc.line;
+					const lines = code.split("\n");
+					err.message += "\n| " + lines.slice(Math.max(0, lineNumber - 3), lineNumber + 2).join("\n| ");
+				}
+				throw err;
+			}
 			const scopeManager = escope.analyze(ast, {
 				ecmaVersion: 6,
 				sourceType: "module",
@@ -529,19 +539,20 @@ class HarmonyExportExpressionDependencyConcatenatedTemplate {
 	}
 
 	apply(dep, source, outputOptions, requestShortener, dependencyTemplates) {
+		let content = "/* harmony default export */ var __WEBPACK_MODULE_DEFAULT_EXPORT__ = ";
 		if(dep.originModule === this.rootModule) {
-			this.originalTemplate.apply(dep, source, outputOptions, requestShortener, dependencyTemplates);
-		} else {
-			const content = "/* harmony default export */ var __WEBPACK_MODULE_DEFAULT_EXPORT__ = ";
-
-			if(dep.range) {
-				source.replace(dep.rangeStatement[0], dep.range[0] - 1, content + "(");
-				source.replace(dep.range[1], dep.rangeStatement[1] - 1, ");");
-				return;
-			}
+			const used = dep.originModule.isUsed("default");
+			const exportsName = dep.originModule.exportsArgument || "exports";
+			if(used) content += `${exportsName}[${JSON.stringify(used)}] = `;
+		}
 
-			source.replace(dep.rangeStatement[0], dep.rangeStatement[1] - 1, content);
+		if(dep.range) {
+			source.replace(dep.rangeStatement[0], dep.range[0] - 1, content + "(");
+			source.replace(dep.range[1], dep.rangeStatement[1] - 1, ");");
+			return;
 		}
+
+		source.replace(dep.rangeStatement[0], dep.rangeStatement[1] - 1, content);
 	}
 }
 
diff --git a/test/cases/scope-hoisting/issue-5314/index.js b/test/cases/scope-hoisting/issue-5314/index.js
new file mode 100644
index 00000000000..2697608c7de
--- /dev/null
+++ b/test/cases/scope-hoisting/issue-5314/index.js
@@ -0,0 +1,9 @@
+import a from "./module";
+
+var obj = {};
+
+it("should allow access to the default export of the root module", function() {
+	a().should.be.eql(obj);
+});
+
+export default obj;
diff --git a/test/cases/scope-hoisting/issue-5314/module.js b/test/cases/scope-hoisting/issue-5314/module.js
new file mode 100644
index 00000000000..f226f2b70a6
--- /dev/null
+++ b/test/cases/scope-hoisting/issue-5314/module.js
@@ -0,0 +1,2 @@
+import b from "./index";
+export default function() { return b; };