fix behavior and add a warning when trying to load an

initial chunk on demand

lib/AsyncDependencyToInitialChunkWarning.js

@@ -0,0 +1,21 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Sean Larkin @thelarkinn
+*/
+"use strict";
+
+const WebpackError = require("./WebpackError");
+
+module.exports = class AsyncDependencyToInitialChunkWarning extends WebpackError {
+	constructor(chunkName, module, loc) {
+		super();
+
+		this.name = "AsyncDependencyToInitialChunkWarning";
+		this.message = `It's not allowed to load an initial chunk on demand. The chunk name "${chunkName}" is already used by an entrypoint.`;
+		this.module = module;
+		this.origin = module;
+		this.originLoc = loc;
+
+		Error.captureStackTrace(this, this.constructor);
+	}
+};

lib/Compilation.js

@@ -20,6 +20,7 @@ const HotUpdateChunkTemplate = require("./HotUpdateChunkTemplate");
 const ModuleTemplate = require("./ModuleTemplate");
 const Dependency = require("./Dependency");
 const ChunkRenderError = require("./ChunkRenderError");
+const AsyncDependencyToInitialChunkWarning = require("./AsyncDependencyToInitialChunkWarning");
 const CachedSource = require("webpack-sources").CachedSource;
 const Stats = require("./Stats");
 const Semaphore = require("./util/Semaphore");
@@ -885,12 +886,19 @@ class Compilation extends Tapable {
 			// but only once (blockChunks map)
 			let c = blockChunks.get(b);
 			if(c === undefined) {
-				c = this.addChunk(b.chunkName, b.module, b.loc);
-				blockChunks.set(b, c);
-				allCreatedChunks.add(c);
-				// We initialize the chunks property
-				// this is later filled with the chunk when needed
-				b.chunks = [];
+				c = this.namedChunks[b.chunkName];
+				if(c && c.isInitial()) {
+					// TODO webpack 4: convert this to an error
+					this.warnings.push(new AsyncDependencyToInitialChunkWarning(b.chunkName, b.module, b.loc));
+					c = chunk;
+				} else {
+					c = this.addChunk(b.chunkName, b.module, b.loc);
+					blockChunks.set(b, c);
+					allCreatedChunks.add(c);
+					// We initialize the chunks property
+					// this is later filled with the chunk when needed
+					b.chunks = [];
+				}
 			}
 
 			// 2. We store the Block+Chunk mapping as dependency for the chunk

lib/Stats.js

@@ -199,15 +199,22 @@ class Stats {
 			text += e.message;
 			if(showErrorDetails && e.details) text += `\n${e.details}`;
 			if(showErrorDetails && e.missing) text += e.missing.map(item => `\n[${item}]`).join("");
-			if(showModuleTrace && e.dependencies && e.origin) {
+			if(showModuleTrace && e.origin) {
 				text += `\n @ ${e.origin.readableIdentifier(requestShortener)}`;
-				e.dependencies.forEach(dep => {
-					if(!dep.loc) return;
-					if(typeof dep.loc === "string") return;
-					const locInfo = formatLocation(dep.loc);
-					if(!locInfo) return;
-					text += ` ${locInfo}`;
-				});
+				if(typeof e.originLoc === "object") {
+					const locInfo = formatLocation(e.originLoc);
+					if(locInfo)
+						text += ` ${locInfo}`;
+				}
+				if(e.dependencies) {
+					e.dependencies.forEach(dep => {
+						if(!dep.loc) return;
+						if(typeof dep.loc === "string") return;
+						const locInfo = formatLocation(dep.loc);
+						if(!locInfo) return;
+						text += ` ${locInfo}`;
+					});
+				}
 				let current = e.origin;
 				while(current.issuer) {
 					current = current.issuer;

test/cases/chunks/weird-reference-to-entry/index.js

@@ -0,0 +1,8 @@
+it("should handle reference to entry chunk correctly", function(done) {
+	import(/* webpackChunkName: "main" */"./module-a").then(function(result) {
+		result.default.should.be.eql("ok");
+		done();
+	}).catch(function(e) {
+		done(e);
+	});
+});

test/cases/chunks/weird-reference-to-entry/module-a.js

@@ -0,0 +1 @@
+export default "ok";

test/cases/chunks/weird-reference-to-entry/warnings.js

@@ -0,0 +1,3 @@
+module.exports = [
+	[/It's not allowed to load an initial chunk on demand\. The chunk name "main" is already used by an entrypoint\./],
+];