improve error message for circular reexports

sokra · sokra · commit 3f6450410af8 · 2018-06-19T23:19:28.000+02:00
fixes webpack#7547
diff --git a/lib/optimize/ConcatenatedModule.js b/lib/optimize/ConcatenatedModule.js
@@ -108,7 +108,8 @@ const getFinalName = (
 	moduleToInfoMap,
 	requestShortener,
 	asCall,
-	strictHarmonyModule
+	strictHarmonyModule,
+	alreadyVisited = new Set()
 ) => {
 	switch (info.type) {
 		case "concatenated": {
@@ -134,6 +135,22 @@ const getFinalName = (
 			}
 			const reexport = info.reexportMap.get(exportName);
 			if (reexport) {
+				if (alreadyVisited.has(reexport)) {
+					throw new Error(
+						`Circular reexports ${Array.from(
+							alreadyVisited,
+							e =>
+								`"${e.module.readableIdentifier(requestShortener)}".${
+									e.exportName
+								}`
+						).join(
+							" --> "
+						)} -(circular)-> "${reexport.module.readableIdentifier(
+							requestShortener
+						)}".${reexport.exportName}`
+					);
+				}
+				alreadyVisited.add(reexport);
 				const refInfo = moduleToInfoMap.get(reexport.module);
 				if (refInfo) {
 					// module is in the concatenation
@@ -143,7 +160,8 @@ const getFinalName = (
 						moduleToInfoMap,
 						requestShortener,
 						asCall,
-						strictHarmonyModule
+						strictHarmonyModule,
+						alreadyVisited
 					);
 				}
 			}
diff --git a/test/configCases/errors/self-reexport/a.js b/test/configCases/errors/self-reexport/a.js
@@ -0,0 +1 @@
+export { something } from "./a";
diff --git a/test/configCases/errors/self-reexport/aa.js b/test/configCases/errors/self-reexport/aa.js
@@ -0,0 +1,3 @@
+import { something } from "./a";
+
+something();
diff --git a/test/configCases/errors/self-reexport/b.js b/test/configCases/errors/self-reexport/b.js
@@ -0,0 +1,7 @@
+
+import { something, other } from "./b";
+
+export {
+	something as other,
+	other as something
+}
diff --git a/test/configCases/errors/self-reexport/bb.js b/test/configCases/errors/self-reexport/bb.js
@@ -0,0 +1,3 @@
+import {something} from "./b";
+
+something();
diff --git a/test/configCases/errors/self-reexport/c1.js b/test/configCases/errors/self-reexport/c1.js
@@ -0,0 +1 @@
+export { something } from "./c2";
diff --git a/test/configCases/errors/self-reexport/c2.js b/test/configCases/errors/self-reexport/c2.js
@@ -0,0 +1 @@
+export { something } from "./c1";
diff --git a/test/configCases/errors/self-reexport/cc.js b/test/configCases/errors/self-reexport/cc.js
@@ -0,0 +1,3 @@
+import {something} from "./c1";
+
+something();
diff --git a/test/configCases/errors/self-reexport/errors.js b/test/configCases/errors/self-reexport/errors.js
@@ -0,0 +1,5 @@
+module.exports = [
+	[/Circular reexports "\.\/a.js"\.something -\(circular\)-> "\.\/a.js"\.something/],
+	[/Circular reexports "\.\/b.js"\.other --> "\.\/b.js"\.something -\(circular\)-> "\.\/b.js"\.other/],
+	[/Circular reexports "\.\/c2.js"\.something --> "\.\/c1.js"\.something -\(circular\)-> "\.\/c2.js"\.something/]
+];
diff --git a/test/configCases/errors/self-reexport/index.js b/test/configCases/errors/self-reexport/index.js
@@ -0,0 +1,7 @@
+it("should not crash on incorrect exports", function() {
+	if(Math.random() < -1) {
+		import(/* webpackChunkName: "a" */ "./aa");
+		import(/* webpackChunkName: "b" */ "./bb");
+		import(/* webpackChunkName: "c" */ "./cc");
+	}
+});
diff --git a/test/configCases/errors/self-reexport/webpack.config.js b/test/configCases/errors/self-reexport/webpack.config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	mode: "production"
+};

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+import { something } from "./a";`
	`2`	`+`
	`3`	`+something();`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+import {something} from "./b";`
	`2`	`+`
	`3`	`+something();`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+import {something} from "./c1";`
	`2`	`+`
	`3`	`+something();`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+module.exports = {`
	`2`	`+ mode: "production"`
	`3`	`+};`