Disable errors for duplicate emitted file names (#3175)

* Disable errors for duplicate emitted file names

And add a test to make sure such emits no longer error spuriously.

Issue #3174

* * Make sure test is red with original code
* Add test description
* Describe better in the TODO comment what the ultimate intention is

src/utils/FileEmitter.ts

@@ -10,7 +10,6 @@ import {
 	errAssetSourceAlreadySet,
 	errChunkNotGeneratedForFileName,
 	errFailedValidation,
-	errFileNameConflict,
 	errFileReferenceIdNotFoundForFilename,
 	errInvalidRollupPhaseForChunkEmission,
 	errNoAssetSourceSet,
@@ -49,9 +48,8 @@ function generateAssetFileName(
 }
 
 function reserveFileNameInBundle(fileName: string, bundle: OutputBundleWithPlaceholders) {
-	if (fileName in bundle) {
-		return error(errFileNameConflict(fileName));
-	}
+	// TODO this should warn if the fileName is already in the bundle,
+	//  but until #3174 is fixed, this raises spurious warnings and is disabled
 	bundle[fileName] = FILE_PLACEHOLDER;
 }
 

test/chunking-form/samples/emit-same-file/_config.js

@@ -0,0 +1,15 @@
+module.exports = {
+	description:
+		'does not throw an error if multiple files with the same name are emitted (until #3174 is fixed)',
+	options: {
+		input: 'main.js',
+		plugins: [
+			{
+				generateBundle() {
+					this.emitFile({ type: 'asset', fileName: 'myfile', source: 'abc' });
+					this.emitFile({ type: 'asset', fileName: 'myfile', source: 'abc' });
+				}
+			}
+		]
+	}
+};

test/chunking-form/samples/emit-same-file/_expected/amd/main.js

@@ -0,0 +1,9 @@
+define(['exports'], function (exports) { 'use strict';
+
+	function hi() { return 2 }
+
+	exports.hi = hi;
+
+	Object.defineProperty(exports, '__esModule', { value: true });
+
+});

test/chunking-form/samples/emit-same-file/_expected/amd/myfile

@@ -0,0 +1 @@
+abc

test/chunking-form/samples/emit-same-file/_expected/cjs/main.js

@@ -0,0 +1,7 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+function hi() { return 2 }
+
+exports.hi = hi;

test/chunking-form/samples/emit-same-file/_expected/cjs/myfile

@@ -0,0 +1 @@
+abc

test/chunking-form/samples/emit-same-file/_expected/es/main.js

@@ -0,0 +1,3 @@
+function hi() { return 2 }
+
+export { hi };

test/chunking-form/samples/emit-same-file/_expected/es/myfile

@@ -0,0 +1 @@
+abc

test/chunking-form/samples/emit-same-file/_expected/system/main.js

@@ -0,0 +1,12 @@
+System.register([], function (exports) {
+	'use strict';
+	return {
+		execute: function () {
+
+			exports('hi', hi);
+
+			function hi() { return 2 }
+
+		}
+	};
+});

test/chunking-form/samples/emit-same-file/_expected/system/myfile

@@ -0,0 +1 @@
+abc

test/chunking-form/samples/emit-same-file/main.js

@@ -0,0 +1 @@
+export function hi() { return 2 }