Normalize property access for imports and exports

lib/dependencies/HarmonyExportExpressionDependency.js

@@ -8,6 +8,7 @@
 const ConcatenationScope = require("../ConcatenationScope");
 const RuntimeGlobals = require("../RuntimeGlobals");
 const makeSerializable = require("../util/makeSerializable");
+const propertyAccess = require("../util/propertyAccess");
 const HarmonyExportInitFragment = require("./HarmonyExportInitFragment");
 const NullDependency = require("./NullDependency");
 
@@ -172,9 +173,9 @@ HarmonyExportExpressionDependency.Template = class HarmonyExportDependencyTempla
 				if (used) {
 					runtimeRequirements.add(RuntimeGlobals.exports);
 					// This is a little bit incorrect as TDZ is not correct, but we can't use const.
-					content = `/* harmony default export */ ${exportsName}[${JSON.stringify(
+					content = `/* harmony default export */ ${exportsName}${propertyAccess(
 						used
-					)}] = `;
+					)} = `;
 				} else {
 					content = `/* unused harmony default export */ var ${name} = `;
 				}

lib/dependencies/HarmonyExportImportedSpecifierDependency.js

@@ -15,6 +15,7 @@ const { countIterable } = require("../util/IterableHelpers");
 const { first, combine } = require("../util/SetHelpers");
 const makeSerializable = require("../util/makeSerializable");
 const propertyAccess = require("../util/propertyAccess");
+const { propertyName } = require("../util/propertyName");
 const { getRuntimeKey, keyToRuntime } = require("../util/runtime");
 const HarmonyExportInitFragment = require("./HarmonyExportInitFragment");
 const HarmonyImportDependency = require("./HarmonyImportDependency");
@@ -1219,7 +1220,7 @@ HarmonyExportImportedSpecifierDependency.Template = class HarmonyExportImportedS
 			valueKey[0]
 		)})) ${
 			RuntimeGlobals.definePropertyGetters
-		}(${exportsName}, { ${JSON.stringify(
+		}(${exportsName}, { ${propertyName(
 			key
 		)}: function() { return ${returnValue}; } });\n`;
 	}

lib/dependencies/HarmonyExportInitFragment.js

@@ -8,6 +8,7 @@
 const InitFragment = require("../InitFragment");
 const RuntimeGlobals = require("../RuntimeGlobals");
 const { first } = require("../util/SetHelpers");
+const { propertyName } = require("../util/propertyName");
 
 /** @typedef {import("webpack-sources").Source} Source */
 /** @typedef {import("../Generator").GenerateContext} GenerateContext */
@@ -150,7 +151,7 @@ class HarmonyExportInitFragment extends InitFragment {
 		);
 		for (const [key, value] of orderedExportMap) {
 			definitions.push(
-				`\n/* harmony export */   ${JSON.stringify(
+				`\n/* harmony export */   ${propertyName(
 					key
 				)}: ${runtimeTemplate.returningFunction(value)}`
 			);

lib/optimize/ConcatenatedModule.js

@@ -27,6 +27,7 @@ const createHash = require("../util/createHash");
 const { makePathsRelative } = require("../util/identifier");
 const makeSerializable = require("../util/makeSerializable");
 const propertyAccess = require("../util/propertyAccess");
+const { propertyName } = require("../util/propertyName");
 const {
 	filterRuntime,
 	intersectRuntime,
@@ -1484,7 +1485,7 @@ class ConcatenatedModule extends Module {
 			const definitions = [];
 			for (const [key, value] of exportsMap) {
 				definitions.push(
-					`\n  ${JSON.stringify(key)}: ${runtimeTemplate.returningFunction(
+					`\n  ${propertyName(key)}: ${runtimeTemplate.returningFunction(
 						value(requestShortener)
 					)}`
 				);
@@ -1529,9 +1530,9 @@ class ConcatenatedModule extends Module {
 						true
 					);
 					nsObj.push(
-						`\n  ${JSON.stringify(
-							usedName
-						)}: ${runtimeTemplate.returningFunction(finalName)}`
+						`\n  ${propertyName(usedName)}: ${runtimeTemplate.returningFunction(
+							finalName
+						)}`
 					);
 				}
 			}

lib/util/propertyAccess.js

@@ -5,60 +5,10 @@
 
 "use strict";
 
-const SAFE_IDENTIFIER = /^[_a-zA-Z$][_a-zA-Z$0-9]*$/;
-const RESERVED_IDENTIFIER = new Set([
-	"break",
-	"case",
-	"catch",
-	"class",
-	"const",
-	"continue",
-	"debugger",
-	"default",
-	"delete",
-	"do",
-	"else",
-	"export",
-	"extends",
-	"finally",
-	"for",
-	"function",
-	"if",
-	"import",
-	"in",
-	"instanceof",
-	"new",
-	"return",
-	"super",
-	"switch",
-	"this",
-	"throw",
-	"try",
-	"typeof",
-	"var",
-	"void",
-	"while",
-	"with",
-	"enum",
-	// strict mode
-	"implements",
-	"interface",
-	"let",
-	"package",
-	"private",
-	"protected",
-	"public",
-	"static",
-	"yield",
-	"yield",
-	// module code
-	"await",
-	// skip future reserved keywords defined under ES1 till ES3
-	// additional
-	"null",
-	"true",
-	"false"
-]);
+const {
+	SAFE_IDENTIFIER,
+	RESERVED_IDENTIFIER
+} = require("../util/propertyName");
 
 /**
  * @param {ArrayLike<string>} properties properties

lib/util/propertyName.js

@@ -0,0 +1,79 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+const SAFE_IDENTIFIER = /^[_a-zA-Z$][_a-zA-Z$0-9]*$/;
+const RESERVED_IDENTIFIER = new Set([
+	"break",
+	"case",
+	"catch",
+	"class",
+	"const",
+	"continue",
+	"debugger",
+	"default",
+	"delete",
+	"do",
+	"else",
+	"export",
+	"extends",
+	"finally",
+	"for",
+	"function",
+	"if",
+	"import",
+	"in",
+	"instanceof",
+	"new",
+	"return",
+	"super",
+	"switch",
+	"this",
+	"throw",
+	"try",
+	"typeof",
+	"var",
+	"void",
+	"while",
+	"with",
+	"enum",
+	// strict mode
+	"implements",
+	"interface",
+	"let",
+	"package",
+	"private",
+	"protected",
+	"public",
+	"static",
+	"yield",
+	"yield",
+	// module code
+	"await",
+	// skip future reserved keywords defined under ES1 till ES3
+	// additional
+	"null",
+	"true",
+	"false"
+]);
+
+/**
+ * @summary Returns a valid JS property name for the given property.
+ * Certain strings like "default", "null", and names with whitespace are not
+ * valid JS property names, so they are returned as strings.
+ *
+ * @param {string} prop property name to analyze
+ * @returns {string} valid JS property name
+ */
+const propertyName = prop => {
+	if (SAFE_IDENTIFIER.test(prop) && !RESERVED_IDENTIFIER.has(prop)) {
+		return prop;
+	} else {
+		return JSON.stringify(prop);
+	}
+};
+
+module.exports = { SAFE_IDENTIFIER, RESERVED_IDENTIFIER, propertyName };