Merge pull request #9153 from webpack/bugfix/dll-side-effects

fix problem with dll and sideEffects

lib/dependencies/HarmonyExportImportedSpecifierDependency.js

@@ -50,6 +50,7 @@ class HarmonyExportImportedSpecifierDependency extends HarmonyImportDependency {
 	) {
 		super(request, originModule, sourceOrder, parserScope);
 		this.id = id;
+		this.redirectedId = undefined;
 		this.name = name;
 		this.activeExports = activeExports;
 		this.otherStarExports = otherStarExports;
@@ -60,9 +61,13 @@ class HarmonyExportImportedSpecifierDependency extends HarmonyImportDependency {
 		return "harmony export imported specifier";
 	}
 
+	get _id() {
+		return this.redirectedId || this.id;
+	}
+
 	getMode(ignoreUnused) {
 		const name = this.name;
-		const id = this.id;
+		const id = this._id;
 		const used = this.originModule.isUsed(name);
 		const importedModule = this._module;
 
@@ -288,7 +293,7 @@ class HarmonyExportImportedSpecifierDependency extends HarmonyImportDependency {
 			};
 		}
 
-		const importedModule = this.module;
+		const importedModule = this._module;
 
 		if (!importedModule) {
 			// no imported module available
@@ -350,11 +355,11 @@ class HarmonyExportImportedSpecifierDependency extends HarmonyImportDependency {
 			// It's not an harmony module
 			if (
 				this.originModule.buildMeta.strictHarmonyModule &&
-				this.id !== "default"
+				this._id !== "default"
 			) {
 				// In strict harmony modules we only support the default export
-				const exportName = this.id
-					? `the named export '${this.id}'`
+				const exportName = this._id
+					? `the named export '${this._id}'`
 					: "the namespace object";
 				return [
 					new HarmonyLinkingError(
@@ -365,20 +370,20 @@ class HarmonyExportImportedSpecifierDependency extends HarmonyImportDependency {
 			return;
 		}
 
-		if (!this.id) {
+		if (!this._id) {
 			return;
 		}
 
-		if (importedModule.isProvided(this.id) !== false) {
+		if (importedModule.isProvided(this._id) !== false) {
 			// It's provided or we are not sure
 			return;
 		}
 
 		// We are sure that it's not provided
 		const idIsNotNameMessage =
-			this.id !== this.name ? ` (reexported as '${this.name}')` : "";
+			this._id !== this.name ? ` (reexported as '${this.name}')` : "";
 		const errorMessage = `"export '${
-			this.id
+			this._id
 		}'${idIsNotNameMessage} was not found in '${this.userRequest}'`;
 		return [new HarmonyLinkingError(errorMessage)];
 	}
@@ -402,6 +407,11 @@ class HarmonyExportImportedSpecifierDependency extends HarmonyImportDependency {
 			importedModule.used + stringifiedUsedExport + stringifiedProvidedExport
 		);
 	}
+
+	disconnect() {
+		super.disconnect();
+		this.redirectedId = undefined;
+	}
 }
 
 module.exports = HarmonyExportImportedSpecifierDependency;

lib/optimize/SideEffectsFlagPlugin.js

@@ -111,8 +111,9 @@ class SideEffectsFlagPlugin {
 							const reason = module.reasons[i];
 							const dep = reason.dependency;
 							if (
-								dep instanceof HarmonyImportSpecifierDependency &&
-								!dep.namespaceObjectAsContext
+								dep instanceof HarmonyExportImportedSpecifierDependency ||
+								(dep instanceof HarmonyImportSpecifierDependency &&
+									!dep.namespaceObjectAsContext)
 							) {
 								const mapping = map.get(dep.id);
 								if (mapping) {

test/__snapshots__/StatsTestCases.test.js.snap

@@ -2231,16 +2231,14 @@ Entrypoint main = main.js
 [0] ./components/src/CompAB/index.js 87 bytes [built]
     [no exports used]
     harmony side effect evaluation ./CompAB [3] ./components/src/index.js 1:0-40
-    harmony export imported specifier ./CompAB [3] ./components/src/index.js 1:0-40
-    harmony export imported specifier ./CompAB [3] ./components/src/index.js 1:0-40
 [1] ./components/src/CompC/CompC.js 33 bytes [built]
     [no exports used]
     harmony side effect evaluation ./CompC [2] ./components/src/CompC/index.js 1:0-34
     harmony export imported specifier ./CompC [2] ./components/src/CompC/index.js 1:0-34
+    harmony export imported specifier ./CompC [3] ./components/src/index.js 2:0-43 (skipped side-effect-free modules)
 [2] ./components/src/CompC/index.js 34 bytes [built]
     [no exports used]
     harmony side effect evaluation ./CompC [3] ./components/src/index.js 2:0-43
-    harmony export imported specifier ./CompC [3] ./components/src/index.js 2:0-43
 [3] ./components/src/index.js 84 bytes [built]
     [no exports used]
     harmony side effect evaluation ./components [6] ./foo.js 1:0-37
@@ -2249,6 +2247,7 @@ Entrypoint main = main.js
     [only some exports used: default]
     harmony side effect evaluation ./CompA [0] ./components/src/CompAB/index.js 1:0-43
     harmony export imported specifier ./CompA [0] ./components/src/CompAB/index.js 1:0-43
+    harmony export imported specifier ./CompAB [3] ./components/src/index.js 1:0-40 (skipped side-effect-free modules)
     harmony import specifier ./components [6] ./foo.js 3:20-25 (skipped side-effect-free modules)
     harmony import specifier ./components  ./main.js 3:15-20 (skipped side-effect-free modules)
 [5] ./components/src/CompAB/utils.js 97 bytes {0} [built]
@@ -2266,11 +2265,12 @@ Entrypoint main = main.js
     |     [only some exports used: default]
     |     harmony side effect evaluation ./CompB [0] ./components/src/CompAB/index.js 2:0-43
     |     harmony export imported specifier ./CompB [0] ./components/src/CompAB/index.js 2:0-43
+    |     harmony export imported specifier ./CompAB [3] ./components/src/index.js 1:0-40 (skipped side-effect-free modules)
     |     harmony import specifier ./components  ./main.js 4:15-20 (skipped side-effect-free modules)"
 `;
 
 exports[`StatsTestCases should print correct stats for side-effects-simple-unused 1`] = `
-"Hash: 518ad50555bd6e64c28b
+"Hash: a5866e21e8cfa3ae1a89
 Time: Xms
 Built at: Thu Jan 01 1970 00:00:00 GMT
   Asset     Size  Chunks             Chunk Names

test/configCases/dll-plugin/0-create-dll/h.js

@@ -0,0 +1 @@
+export { B } from "./h1.js";

test/configCases/dll-plugin/0-create-dll/h1.js

@@ -0,0 +1,2 @@
+export { A } from "./ha.js";
+export { B } from "./hb.js";

test/configCases/dll-plugin/0-create-dll/ha.js

@@ -0,0 +1 @@
+export const A = "A";

test/configCases/dll-plugin/0-create-dll/hb.js

@@ -0,0 +1 @@
+export const B = "B";

test/configCases/dll-plugin/0-create-dll/webpack.config.js

@@ -2,7 +2,7 @@ var path = require("path");
 var webpack = require("../../../../");
 
 module.exports = {
-	entry: ["./a", "./b", "./_d", "./_e", "./f", "./g.abc"],
+	entry: ["./a", "./b", "./_d", "./_e", "./f", "./g.abc", "./h"],
 	resolve: {
 		extensions: [".js", ".jsx"]
 	},
@@ -19,9 +19,16 @@ module.exports = {
 				options: {
 					test: 1
 				}
+			},
+			{
+				test: /0-create-dll.h/,
+				sideEffects: false
 			}
 		]
 	},
+	optimization: {
+		sideEffects: true
+	},
 	plugins: [
 		new webpack.DllPlugin({
 			path: path.resolve(

test/configCases/dll-plugin/1-use-dll/index.js

@@ -1,6 +1,7 @@
 import d from "dll/d";
 import { x1, y2 } from "./e";
 import { x2, y1 } from "dll/e";
+import { B } from "dll/h";
 
 it("should load a module from dll", function() {
 	expect(require("dll/a")).toBe("a");
@@ -11,10 +12,12 @@ it("should load a module of non-default type without extension from dll", functi
 });
 
 it("should load an async module from dll", function(done) {
-	require("dll/b")().then(function(c) {
-		expect(c).toEqual(nsObj({ default: "c" }));
-		done();
-	}).catch(done);
+	require("dll/b")()
+		.then(function(c) {
+			expect(c).toEqual(nsObj({ default: "c" }));
+			done();
+		})
+		.catch(done);
 });
 
 it("should load an harmony module from dll (default export)", function() {
@@ -33,7 +36,9 @@ it("should load a module with loader applied", function() {
 });
 
 it("should give modules the correct ids", function() {
-	expect(Object.keys(__webpack_modules__).filter(m => !m.startsWith("../.."))).toEqual([
+	expect(
+		Object.keys(__webpack_modules__).filter(m => !m.startsWith("../.."))
+	).toEqual([
 		"./index.js",
 		"dll-reference ../0-create-dll/dll.js",
 		"dll/a.js",
@@ -43,6 +48,11 @@ it("should give modules the correct ids", function() {
 		"dll/e1.js",
 		"dll/e2.js",
 		"dll/f.jsx",
-		"dll/g.abc.js"
-    ]);
+		"dll/g.abc.js",
+		"dll/h.js"
+	]);
+});
+
+it("should not crash on side-effect-free modules", function() {
+	expect(B).toBe("B");
 });

test/configCases/dll-plugin/2-use-dll-without-scope/index.js

@@ -1,6 +1,8 @@
 import d from "../0-create-dll/d";
 import { x1, y2 } from "./e";
 import { x2, y1 } from "../0-create-dll/e";
+import { B } from "../0-create-dll/h";
+import { A } from "../0-create-dll/h1";
 
 it("should load a module from dll", function() {
 	expect(require("../0-create-dll/a")).toBe("a");
@@ -11,10 +13,12 @@ it("should load a module of non-default type without extension from dll", functi
 });
 
 it("should load an async module from dll", function(done) {
-	require("../0-create-dll/b")().then(function(c) {
-		expect(c).toEqual(nsObj({ default: "c" }));
-		done();
-	}).catch(done);
+	require("../0-create-dll/b")()
+		.then(function(c) {
+			expect(c).toEqual(nsObj({ default: "c" }));
+			done();
+		})
+		.catch(done);
 });
 
 it("should load an harmony module from dll (default export)", function() {
@@ -33,7 +37,9 @@ it("should load a module with loader applied", function() {
 });
 
 it("should give modules the correct ids", function() {
-	expect(Object.keys(__webpack_modules__).filter(m => !m.startsWith("../.."))).toEqual([
+	expect(
+		Object.keys(__webpack_modules__).filter(m => !m.startsWith("../.."))
+	).toEqual([
 		"../0-create-dll/a.js",
 		"../0-create-dll/b.js",
 		"../0-create-dll/d.js",
@@ -42,7 +48,17 @@ it("should give modules the correct ids", function() {
 		"../0-create-dll/e2.js",
 		"../0-create-dll/f.jsx",
 		"../0-create-dll/g.abc.js",
+		"../0-create-dll/h.js",
+		"../0-create-dll/hb.js",
 		"./index.js",
 		"dll-reference ../0-create-dll/dll.js"
 	]);
 });
+
+it("should not crash on side-effect-free modules", function() {
+	expect(B).toBe("B");
+});
+
+it("should be able to reference side-effect-free reexport-only module", function() {
+	expect(A).toBe("A");
+});