Use id of last module in chunk as name base for auto-generated chunks (…

…#3025)

* Use new FileEmitter for basic cases around assets. TODO: Replace asset
hooks completely, create tests for assets using the new hooks.

* Migrate assets to new file emitter

* Remove assetsById from Graph

* Implement emitFile for assets

* Internally use EmittedFile in the file emitter

* Deprecate emitAsset and ROLLUP_ASSET_URL

* Deprecate getAssetFileName

* Merge chunk emission into unified API and deprecated previous API

* Allow emitting files with fixed names

* Support unnamed assets

* Improve chunk name assignment

* Initial support for chunk file names

* Allow specifying explicit file names for emitted chunks

* Fix some TODOs

* Test ids remain stable when the transform hook is cached and make test
more stable

* Refine error handling

* Test some more errors

* Refine file emission

* Refactor file emitter to have a single code path for asset finalization

* Deduplicated emitted assets without a specific file name

* Only use the alias as name for a manual chunk if the chunk is not facade
for an entry point

* Generate separate facades for duplicate named user-defined entry points

* Always create facades for explicit file names

* Test edge cases

* Test and refactor handling of dynamic relative imports

* Use async-await in generate function, remove error condition

* Improve and test pattern validation

* Test file emitter edge cases

* Improve plugin error handling

* Add documentation

* Use id of last module in chunk as name base for auto-generated chunks

src/Chunk.ts

@@ -999,10 +999,7 @@ export default class Chunk {
 		if (this.fileName) {
 			return getAliasName(this.fileName);
 		}
-		for (const module of this.orderedModules) {
-			if (module.chunkName) return module.chunkName;
-		}
-		return 'chunk';
+		return getAliasName(this.orderedModules[this.orderedModules.length - 1].id);
 	}
 
 	private getRelativePath(targetPath: string): string {

test/chunking-form/samples/basic-chunking/_expected/amd/main1.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk'], function (dep2) { 'use strict';
+define(['./generated-dep2'], function (dep2) { 'use strict';
 
   function fn () {
     console.log('dep1 fn');

test/chunking-form/samples/basic-chunking/_expected/amd/main2.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk'], function (dep2) { 'use strict';
+define(['./generated-dep2'], function (dep2) { 'use strict';
 
   function fn () {
     console.log('lib1 fn');

test/chunking-form/samples/basic-chunking/_expected/cjs/main1.js

@@ -1,6 +1,6 @@
 'use strict';
 
-var dep2 = require('./generated-chunk.js');
+var dep2 = require('./generated-dep2.js');
 
 function fn () {
   console.log('dep1 fn');

test/chunking-form/samples/basic-chunking/_expected/cjs/main2.js

@@ -1,6 +1,6 @@
 'use strict';
 
-var dep2 = require('./generated-chunk.js');
+var dep2 = require('./generated-dep2.js');
 
 function fn () {
   console.log('lib1 fn');

test/chunking-form/samples/basic-chunking/_expected/es/main1.js

@@ -1,4 +1,4 @@
-import { f as fn$1 } from './generated-chunk.js';
+import { f as fn$1 } from './generated-dep2.js';
 
 function fn () {
   console.log('dep1 fn');

test/chunking-form/samples/basic-chunking/_expected/es/main2.js

@@ -1,4 +1,4 @@
-import { f as fn$2 } from './generated-chunk.js';
+import { f as fn$2 } from './generated-dep2.js';
 
 function fn () {
   console.log('lib1 fn');

test/chunking-form/samples/basic-chunking/_expected/system/main1.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js'], function (exports) {
+System.register(['./generated-dep2.js'], function (exports) {
   'use strict';
   var fn$1;
   return {

test/chunking-form/samples/basic-chunking/_expected/system/main2.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js'], function (exports) {
+System.register(['./generated-dep2.js'], function (exports) {
   'use strict';
   var fn$2;
   return {

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/amd/generated-shared2.js

@@ -0,0 +1,10 @@
+define(['exports', './generated-dep1', './generated-dep2'], function (exports, dep1, dep2) { 'use strict';
+
+	var x = dep1.x + 1;
+
+	var y = dep2.x + 1;
+
+	exports.x = x;
+	exports.y = y;
+
+});

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/amd/main1.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk', './generated-chunk2', './generated-chunk3'], function (dep1, shared2, dep2) { 'use strict';
+define(['./generated-dep1', './generated-shared2', './generated-dep2'], function (dep1, shared2, dep2) { 'use strict';
 
 	console.log(shared2.x + shared2.y);
 

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/amd/main2.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk', './generated-chunk2', './generated-chunk3'], function (dep1, shared2, dep2) { 'use strict';
+define(['./generated-dep1', './generated-shared2', './generated-dep2'], function (dep1, shared2, dep2) { 'use strict';
 
 
 

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/amd/main3.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk'], function (dep1) { 'use strict';
+define(['./generated-dep1'], function (dep1) { 'use strict';
 
 
 

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/amd/main4.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk3'], function (dep2) { 'use strict';
+define(['./generated-dep2'], function (dep2) { 'use strict';
 
 
 

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/cjs/generated-shared2.js

@@ -0,0 +1,11 @@
+'use strict';
+
+var dep1 = require('./generated-dep1.js');
+var dep2 = require('./generated-dep2.js');
+
+var x = dep1.x + 1;
+
+var y = dep2.x + 1;
+
+exports.x = x;
+exports.y = y;

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/cjs/main1.js

@@ -1,7 +1,7 @@
 'use strict';
 
-require('./generated-chunk.js');
-var shared2 = require('./generated-chunk2.js');
-require('./generated-chunk3.js');
+require('./generated-dep1.js');
+var shared2 = require('./generated-shared2.js');
+require('./generated-dep2.js');
 
 console.log(shared2.x + shared2.y);

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/cjs/main2.js

@@ -1,6 +1,6 @@
 'use strict';
 
-require('./generated-chunk.js');
-require('./generated-chunk2.js');
-require('./generated-chunk3.js');
+require('./generated-dep1.js');
+require('./generated-shared2.js');
+require('./generated-dep2.js');
 

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/cjs/main3.js

@@ -1,4 +1,4 @@
 'use strict';
 
-require('./generated-chunk.js');
+require('./generated-dep1.js');
 

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/cjs/main4.js

@@ -1,4 +1,4 @@
 'use strict';
 
-require('./generated-chunk3.js');
+require('./generated-dep2.js');
 

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/es/generated-shared2.js

@@ -0,0 +1,8 @@
+import { x as x$1 } from './generated-dep1.js';
+import { x as x$2 } from './generated-dep2.js';
+
+var x = x$1 + 1;
+
+var y = x$2 + 1;
+
+export { x, y };

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/es/main1.js

@@ -1,5 +1,5 @@
-import './generated-chunk.js';
-import { x, y } from './generated-chunk2.js';
-import './generated-chunk3.js';
+import './generated-dep1.js';
+import { x, y } from './generated-shared2.js';
+import './generated-dep2.js';
 
 console.log(x + y);

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/es/main2.js

@@ -1,3 +1,3 @@
-import './generated-chunk.js';
-import './generated-chunk2.js';
-import './generated-chunk3.js';
+import './generated-dep1.js';
+import './generated-shared2.js';
+import './generated-dep2.js';

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/es/main3.js

@@ -1 +1 @@
-import './generated-chunk.js';
+import './generated-dep1.js';

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/es/main4.js

@@ -1 +1 @@
-import './generated-chunk3.js';
+import './generated-dep2.js';

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/system/generated-chunk2.js → test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/system/generated-shared2.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js', './generated-chunk3.js'], function (exports) {
+System.register(['./generated-dep1.js', './generated-dep2.js'], function (exports) {
 	'use strict';
 	var x$1, x$2;
 	return {

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/system/main1.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js', './generated-chunk2.js', './generated-chunk3.js'], function () {
+System.register(['./generated-dep1.js', './generated-shared2.js', './generated-dep2.js'], function () {
 	'use strict';
 	var x, y;
 	return {

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/system/main2.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js', './generated-chunk2.js', './generated-chunk3.js'], function () {
+System.register(['./generated-dep1.js', './generated-shared2.js', './generated-dep2.js'], function () {
 	'use strict';
 	return {
 		setters: [function () {}, function () {}, function () {}],

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/system/main3.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js'], function () {
+System.register(['./generated-dep1.js'], function () {
 	'use strict';
 	return {
 		setters: [function () {}],

test/chunking-form/samples/chunk-deshadowing-reassignment/_expected/system/main4.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk3.js'], function () {
+System.register(['./generated-dep2.js'], function () {
 	'use strict';
 	return {
 		setters: [function () {}],

test/chunking-form/samples/chunk-execution-order/_expected/amd/generated-dep11.js

@@ -0,0 +1,5 @@
+define(['./generated-dep111', './generated-dep112'], function (dep111, dep112) { 'use strict';
+
+	console.log('11');
+
+});

test/chunking-form/samples/chunk-execution-order/_expected/amd/main1.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk', './generated-chunk2', './generated-chunk3'], function (dep111, dep112, dep11) { 'use strict';
+define(['./generated-dep111', './generated-dep112', './generated-dep11'], function (dep111, dep112, dep11) { 'use strict';
 
 	console.log('1');
 

test/chunking-form/samples/chunk-execution-order/_expected/amd/main2.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk', './generated-chunk2', './generated-chunk3'], function (dep111, dep112, dep11) { 'use strict';
+define(['./generated-dep111', './generated-dep112', './generated-dep11'], function (dep111, dep112, dep11) { 'use strict';
 
 
 

test/chunking-form/samples/chunk-execution-order/_expected/amd/main3.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk'], function (dep111) { 'use strict';
+define(['./generated-dep111'], function (dep111) { 'use strict';
 
 
 

test/chunking-form/samples/chunk-execution-order/_expected/amd/main4.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk2'], function (dep112) { 'use strict';
+define(['./generated-dep112'], function (dep112) { 'use strict';
 
 
 

test/chunking-form/samples/chunk-execution-order/_expected/cjs/generated-dep11.js

@@ -0,0 +1,6 @@
+'use strict';
+
+require('./generated-dep111.js');
+require('./generated-dep112.js');
+
+console.log('11');

test/chunking-form/samples/chunk-execution-order/_expected/cjs/main1.js

@@ -1,8 +1,8 @@
 'use strict';
 
-require('./generated-chunk.js');
-var dep112 = require('./generated-chunk2.js');
-require('./generated-chunk3.js');
+require('./generated-dep111.js');
+var dep112 = require('./generated-dep112.js');
+require('./generated-dep11.js');
 
 console.log('1');
 

test/chunking-form/samples/chunk-execution-order/_expected/cjs/main2.js

@@ -1,6 +1,6 @@
 'use strict';
 
-require('./generated-chunk.js');
-require('./generated-chunk2.js');
-require('./generated-chunk3.js');
+require('./generated-dep111.js');
+require('./generated-dep112.js');
+require('./generated-dep11.js');
 

test/chunking-form/samples/chunk-execution-order/_expected/cjs/main3.js

@@ -1,4 +1,4 @@
 'use strict';
 
-require('./generated-chunk.js');
+require('./generated-dep111.js');
 

test/chunking-form/samples/chunk-execution-order/_expected/cjs/main4.js

@@ -1,4 +1,4 @@
 'use strict';
 
-require('./generated-chunk2.js');
+require('./generated-dep112.js');
 

test/chunking-form/samples/chunk-execution-order/_expected/es/generated-dep11.js

@@ -0,0 +1,4 @@
+import './generated-dep111.js';
+import './generated-dep112.js';
+
+console.log('11');

test/chunking-form/samples/chunk-execution-order/_expected/es/main1.js

@@ -1,6 +1,6 @@
-import './generated-chunk.js';
-import { x } from './generated-chunk2.js';
-import './generated-chunk3.js';
+import './generated-dep111.js';
+import { x } from './generated-dep112.js';
+import './generated-dep11.js';
 
 console.log('1');
 

test/chunking-form/samples/chunk-execution-order/_expected/es/main2.js

@@ -1,3 +1,3 @@
-import './generated-chunk.js';
-import './generated-chunk2.js';
-import './generated-chunk3.js';
+import './generated-dep111.js';
+import './generated-dep112.js';
+import './generated-dep11.js';

test/chunking-form/samples/chunk-execution-order/_expected/es/main3.js

@@ -1 +1 @@
-import './generated-chunk.js';
+import './generated-dep111.js';

test/chunking-form/samples/chunk-execution-order/_expected/es/main4.js

@@ -1 +1 @@
-import './generated-chunk2.js';
+import './generated-dep112.js';

test/chunking-form/samples/chunk-execution-order/_expected/system/generated-chunk3.js → test/chunking-form/samples/chunk-execution-order/_expected/system/generated-dep11.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js', './generated-chunk2.js'], function () {
+System.register(['./generated-dep111.js', './generated-dep112.js'], function () {
 	'use strict';
 	return {
 		setters: [function () {}, function () {}],

test/chunking-form/samples/chunk-execution-order/_expected/system/main1.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js', './generated-chunk2.js', './generated-chunk3.js'], function () {
+System.register(['./generated-dep111.js', './generated-dep112.js', './generated-dep11.js'], function () {
 	'use strict';
 	var x;
 	return {

test/chunking-form/samples/chunk-execution-order/_expected/system/main2.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js', './generated-chunk2.js', './generated-chunk3.js'], function () {
+System.register(['./generated-dep111.js', './generated-dep112.js', './generated-dep11.js'], function () {
 	'use strict';
 	return {
 		setters: [function () {}, function () {}, function () {}],

test/chunking-form/samples/chunk-execution-order/_expected/system/main3.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk.js'], function () {
+System.register(['./generated-dep111.js'], function () {
 	'use strict';
 	return {
 		setters: [function () {}],

test/chunking-form/samples/chunk-execution-order/_expected/system/main4.js

@@ -1,4 +1,4 @@
-System.register(['./generated-chunk2.js'], function () {
+System.register(['./generated-dep112.js'], function () {
 	'use strict';
 	return {
 		setters: [function () {}],

test/chunking-form/samples/chunk-export-deshadowing/_expected/amd/main1.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk'], function (dep1) { 'use strict';
+define(['./generated-dep1'], function (dep1) { 'use strict';
 
   class Main1 {
     constructor () {

test/chunking-form/samples/chunk-export-deshadowing/_expected/amd/main2.js

@@ -1,4 +1,4 @@
-define(['./generated-chunk'], function (dep1) { 'use strict';
+define(['./generated-dep1'], function (dep1) { 'use strict';
 
   class Main2 {
     constructor () {