fixes #2977

lib/FlagDependencyExportsPlugin.js

@@ -59,6 +59,7 @@ FlagDependencyExportsPlugin.prototype.apply = function(compiler) {
 					});
 				}
 				var changed = false;
+				if(module.providedExports !== true) {
 					if(exports === true) {
 						module.providedExports = true;
 						changed = true;
@@ -70,6 +71,7 @@ FlagDependencyExportsPlugin.prototype.apply = function(compiler) {
 							changed = true;
 						}
 					};
+				}
 				if(changed) {
 					var deps = dependencies["$" + module.identifier()];
 					if(deps) {

test/statsCases/tree-shaking/a.js

@@ -0,0 +1 @@
+export var a;

test/statsCases/tree-shaking/b.js

@@ -0,0 +1 @@
+export var b;

test/statsCases/tree-shaking/expected.txt

@@ -0,0 +1,25 @@
+Hash: 11b123cb23c353a91fe4
+Time: Xms
+    Asset     Size  Chunks             Chunk Names
+bundle.js  6.46 kB       0  [emitted]  main
+chunk    {0} bundle.js (main) 512 bytes [entry] [rendered]
+   [0] (webpack)/test/statsCases/tree-shaking/a.js 13 bytes {0} [built]
+       [exports: a]
+       [only some exports used: a]
+   [1] (webpack)/test/statsCases/tree-shaking/b.js 13 bytes {0} [built]
+       [exports: b]
+       [only some exports used: ]
+   [2] (webpack)/test/statsCases/tree-shaking/unknown.js 0 bytes {0} [built]
+       [only some exports used: a, c]
+   [3] (webpack)/test/statsCases/tree-shaking/reexport-known.js 49 bytes {0} [built]
+       [exports: a, b]
+       [only some exports used: a]
+   [4] (webpack)/test/statsCases/tree-shaking/reexport-star-known.js 41 bytes {0} [built]
+       [exports: a, b]
+       [only some exports used: a]
+   [5] (webpack)/test/statsCases/tree-shaking/reexport-star-unknown.js 68 bytes {0} [built]
+       [only some exports used: a, c]
+   [6] (webpack)/test/statsCases/tree-shaking/reexport-unknown.js 83 bytes {0} [built]
+       [exports: a, b, c, d]
+       [only some exports used: a, c]
+   [7] (webpack)/test/statsCases/tree-shaking/index.js 245 bytes {0} [built]

test/statsCases/tree-shaking/index.js

@@ -0,0 +1,6 @@
+import { a as a1 } from "./reexport-known";
+import { a as a2, c as c2 } from "./reexport-unknown";
+import { a as a3} from "./reexport-star-known";
+import { a as a4, c as c4 } from "./reexport-star-unknown";
+
+console.log(a1, a2, a3, a4, c2, c4);

test/statsCases/tree-shaking/reexport-known.js

@@ -0,0 +1,2 @@
+export { a } from "./a";
+export { b } from "./b";

test/statsCases/tree-shaking/reexport-star-known.js

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

test/statsCases/tree-shaking/reexport-star-unknown.js

@@ -0,0 +1,3 @@
+export * from "./a";
+export * from "./b";
+export * from "./unknown";

test/statsCases/tree-shaking/reexport-unknown.js

@@ -0,0 +1,3 @@
+export { a } from "./a";
+export { b } from "./b";
+export { c, d } from "./unknown";

test/statsCases/tree-shaking/webpack.config.js

@@ -0,0 +1,12 @@
+module.exports = {
+	entry: "./index",
+	output: {
+		filename: "bundle.js"
+	},
+	stats: {
+		chunkModules: false,
+		modules: true,
+		providedExports: true,
+		usedExports: true
+	}
+};