#2585 - Feature adds ability to use a function that returns a pattern string in all places where you could use a pattern string befor.

docs/05-plugin-development.md

@@ -236,12 +236,12 @@ Output generation hooks can provide information about a generated bundle and mod
 The first hook of the output generation phase is [outputOptions](guide/en/#outputoptions), the last one is either [generateBundle](guide/en/#generatebundle) if the output was successfully generated via `bundle.generate(...)`, [writeBundle](guide/en/#writebundle) if the output was successfully generated via `bundle.write(...)`, or [renderError](guide/en/#rendererror) if an error occurred at any time during the output generation.
 
 #### `augmentChunkHash`
-Type: `(preRenderedChunk: PreRenderedChunk) => string`<br>
+Type: `(chunkInfo: ChunkInfo) => string`<br>
 Kind: `sync, sequential`<br>
 Previous Hook: [`renderDynamicImport`](guide/en/#renderdynamicimport) for each dynamic import expression.<br>
 Next Hook: [`resolveFileUrl`](guide/en/#resolvefileurl) for each use of `import.meta.ROLLUP_FILE_URL_referenceId` and [`resolveImportMeta`](guide/en/#resolveimportmeta) for all other accesses to `import.meta`.
 
-Can be used to augment the hash of individual chunks. Called for each Rollup output chunk. Returning a falsy value will not modify the hash. Truthy values will be passed to [`hash.update`](https://nodejs.org/dist/latest-v12.x/docs/api/crypto.html#crypto_hash_update_data_inputencoding).
+Can be used to augment the hash of individual chunks. Called for each Rollup output chunk. Returning a falsy value will not modify the hash. Truthy values will be passed to [`hash.update`](https://nodejs.org/dist/latest-v12.x/docs/api/crypto.html#crypto_hash_update_data_inputencoding). The `chunkInfo` is a reduced version of the one in [`generateBundle`](guide/en/#generatebundle) without properties that rely on file names.
 
 The following plugin will invalidate the hash of chunk `foo` with the timestamp of the last build:
 
@@ -282,6 +282,7 @@ Called at the end of `bundle.generate()` or immediately before the files are wri
 // AssetInfo
 {
   fileName: string,
+  name?: string,
   source: string | Uint8Array,
   type: 'asset',
 }

docs/999-big-list-of-options.md

@@ -359,17 +359,19 @@ export default {
 
 
 #### output.assetFileNames
-Type: `string`<br>
+Type: `string | ((assetInfo: AssetInfo) => string)`<br>
 CLI: `--assetFileNames <pattern>`<br>
 Default: `"assets/[name]-[hash][extname]"`
 
-The pattern to use for naming custom emitted assets to include in the build output. Pattern supports the following placeholders:
+The pattern to use for naming custom emitted assets to include in the build output, or a function that is called per asset to return such a pattern. Patterns support the following placeholders:
  * `[extname]`: The file extension of the asset including a leading dot, e.g. `.css`.
  * `[ext]`: The file extension without a leading dot, e.g. `css`.
  * `[hash]`: A hash based on the name and content of the asset.
  * `[name]`: The file name of the asset excluding any extension.
 
-Forward slashes `/` can be used to place files in sub-directories. See also [`output.chunkFileNames`](guide/en/#outputchunkfilenames), [`output.entryFileNames`](guide/en/#outputentryfilenames).
+Forward slashes `/` can be used to place files in sub-directories. When using a function, `assetInfo` is a reduced version of the one in [`generateBundle`](guide/en/#generatebundle) without the `fileName`. See also [`output.chunkFileNames`](guide/en/#outputchunkfilenames), [`output.entryFileNames`](guide/en/#outputentryfilenames). 
+
+You can also supply a function that returns a pattern as string.
 
 #### output.banner/output.footer
 Type: `string | (() => string | Promise<string>)`<br>
@@ -392,16 +394,18 @@ export default {
 See also [`output.intro/output.outro`](guide/en/#outputintrooutputoutro).
 
 #### output.chunkFileNames
-Type: `string`<br>
+Type: `string | ((chunkInfo: ChunkInfo) => string)`<br>
 CLI: `--chunkFileNames <pattern>`<br>
 Default: `"[name]-[hash].js"`
 
-The pattern to use for naming shared chunks created when code-splitting. Pattern supports the following placeholders:
+The pattern to use for naming shared chunks created when code-splitting, or a function that is called per chunk to return such a pattern. Patterns support the following placeholders:
  * `[format]`: The rendering format defined in the output options, e.g. `es` or `cjs`.
  * `[hash]`: A hash based on the content of the chunk and the content of all its dependencies.
  * `[name]`: The name of the chunk. This can be explicitly set via the [`output.manualChunks`](guide/en/#outputmanualchunks) option or when the chunk is created by a plugin via [`this.emitFile`](guide/en/#thisemitfileemittedfile-emittedchunk--emittedasset--string). Otherwise it will be derived from the chunk contents.
 
-Forward slashes `/` can be used to place files in sub-directories. See also [`output.assetFileNames`](guide/en/#outputassetfilenames), [`output.entryFileNames`](guide/en/#outputentryfilenames).
+Forward slashes `/` can be used to place files in sub-directories. When using a function, `chunkInfo` is a reduced version of the one in [`generateBundle`](guide/en/#generatebundle) without properties that depend on file names. See also [`output.assetFileNames`](guide/en/#outputassetfilenames), [`output.entryFileNames`](guide/en/#outputentryfilenames).
+
+You can also supply a function that returns a pattern as string.
 
 #### output.compact
 Type: `boolean`<br>
@@ -411,23 +415,25 @@ Default: `false`
 This will minify the wrapper code generated by rollup. Note that this does not affect code written by the user. This option is useful when bundling pre-minified code.
 
 #### output.entryFileNames
-Type: `string`<br>
+Type: `string | ((chunkInfo: ChunkInfo) => string)`<br>
 CLI: `--entryFileNames <pattern>`<br>
 Default: `"[name].js"`
 
-The pattern to use for chunks created from entry points. Pattern supports the following placeholders:
+The pattern to use for chunks created from entry points, or a function that is called per entry chunk to return such a pattern. Patterns support the following placeholders:
 * `[format]`: The rendering format defined in the output options, e.g. `es` or `cjs`.
 * `[hash]`: A hash based on the content of the entry point and the content of all its dependencies.
 * `[name]`: The file name (without extension) of the entry point, unless the object form of input was used to define a different name.
 
-Forward slashes `/` can be used to place files in sub-directories. See also [`output.assetFileNames`](guide/en/#outputassetfilenames), [`output.chunkFileNames`](guide/en/#outputchunkfilenames).
+Forward slashes `/` can be used to place files in sub-directories. When using a function, `chunkInfo` is a reduced version of the one in [`generateBundle`](guide/en/#generatebundle) without properties that depend on file names. See also [`output.assetFileNames`](guide/en/#outputassetfilenames), [`output.chunkFileNames`](guide/en/#outputchunkfilenames).
 
 This pattern will also be used when using the [`output.preserveModules`](guide/en/#outputpreservemodules) option. Here there is a different set of placeholders available, though:
 * `[format]`: The rendering format defined in the output options.
 * `[name]`: The file name (without extension) of the file.
 * `[ext]`: The extension of the file.
 * `[extname]`: The extension of the file, prefixed by `.` if it is not empty.
 
+You can also supply a function that returns a pattern as string.
+
 #### output.extend
 Type: `boolean`<br>
 CLI: `--extend`/`--no-extend`<br>

src/Bundle.ts

@@ -84,7 +84,7 @@ export default class Bundle {
 		for (const chunk of chunks) {
 			const chunkDescription = (outputBundle[
 				chunk.id!
-			] = chunk.getPrerenderedChunk() as OutputChunk);
+			] = chunk.getChunkInfoWithFileNames() as OutputChunk);
 			chunkDescription.fileName = chunk.id!;
 		}
 		await Promise.all(

src/Chunk.ts

@@ -387,19 +387,24 @@ export default class Chunk {
 				? [options.entryFileNames, 'output.entryFileNames']
 				: [options.chunkFileNames, 'output.chunkFileNames'];
 		return makeUnique(
-			renderNamePattern(pattern, patternName, {
-				format: () => options.format,
-				hash: () =>
-					includeHash
-						? this.computeContentHashWithDependencies(
-								addons,
-								options,
-								existingNames,
-								outputPluginDriver
-						  )
-						: '[hash]',
-				name: () => this.getChunkName()
-			}),
+			renderNamePattern(
+				pattern,
+				patternName,
+				{
+					format: () => options.format,
+					hash: () =>
+						includeHash
+							? this.computeContentHashWithDependencies(
+									addons,
+									options,
+									existingNames,
+									outputPluginDriver
+							  )
+							: '[hash]',
+					name: () => this.getChunkName()
+				},
+				this.getChunkInfo.bind(this)
+			),
 			existingNames
 		);
 	}
@@ -422,44 +427,33 @@ export default class Chunk {
 				: options.entryFileNames;
 			path = relative(
 				preserveModulesRelativeDir,
-				`${dirname(sanitizedId)}/${renderNamePattern(pattern, 'output.entryFileNames', {
-					ext: () => extension.substr(1),
-					extname: () => extension,
-					format: () => options.format as string,
-					name: () => this.getChunkName()
-				})}`
+				`${dirname(sanitizedId)}/${renderNamePattern(
+					pattern,
+					'output.entryFileNames',
+					{
+						ext: () => extension.substr(1),
+						extname: () => extension,
+						format: () => options.format as string,
+						name: () => this.getChunkName()
+					},
+					this.getChunkInfo.bind(this)
+				)}`
 			);
 		} else {
 			path = `_virtual/${basename(sanitizedId)}`;
 		}
 		return makeUnique(normalize(path), existingNames);
 	}
 
-	getChunkName(): string {
-		return this.name || (this.name = sanitizeFileName(this.getFallbackChunkName()));
-	}
-
-	getExportNames(): string[] {
-		return (
-			this.sortedExportNames || (this.sortedExportNames = Object.keys(this.exportsByName!).sort())
-		);
-	}
-
-	getPrerenderedChunk(): PreRenderedChunk {
+	getChunkInfo(): PreRenderedChunk {
 		const facadeModule = this.facadeModule;
 		const getChunkName = this.getChunkName.bind(this);
 		return {
-			code: undefined,
-			dynamicImports: Array.from(this.dynamicDependencies, getId),
 			exports: this.getExportNames(),
 			facadeModuleId: facadeModule && facadeModule.id,
-			fileName: undefined,
-			implicitlyLoadedBefore: Array.from(this.implicitlyLoadedBefore, getId),
-			imports: Array.from(this.dependencies, getId),
 			isDynamicEntry: this.dynamicEntryModules.length > 0,
 			isEntry: facadeModule !== null && facadeModule.isEntryPoint,
 			isImplicitEntry: this.implicitEntryModules.length > 0,
-			map: undefined,
 			modules: this.renderedModules!,
 			get name() {
 				return getChunkName();
@@ -468,13 +462,34 @@ export default class Chunk {
 		};
 	}
 
+	getChunkInfoWithFileNames(): RenderedChunk {
+		return Object.assign(this.getChunkInfo(), {
+			code: undefined,
+			dynamicImports: Array.from(this.dynamicDependencies, getId),
+			fileName: this.id!,
+			implicitlyLoadedBefore: Array.from(this.implicitlyLoadedBefore, getId),
+			imports: Array.from(this.dependencies, getId),
+			map: undefined
+		});
+	}
+
+	getChunkName(): string {
+		return this.name || (this.name = sanitizeFileName(this.getFallbackChunkName()));
+	}
+
+	getExportNames(): string[] {
+		return (
+			this.sortedExportNames || (this.sortedExportNames = Object.keys(this.exportsByName!).sort())
+		);
+	}
+
 	getRenderedHash(outputPluginDriver: PluginDriver): string {
 		if (this.renderedHash) return this.renderedHash;
 		const hash = createHash();
 		const hashAugmentation = outputPluginDriver.hookReduceValueSync(
 			'augmentChunkHash',
 			'',
-			[this.getPrerenderedChunk()],
+			[this.getChunkInfo()],
 			(hashAugmentation, pluginHash) => {
 				if (pluginHash) {
 					hashAugmentation += pluginHash;

src/rollup/types.d.ts

@@ -545,15 +545,15 @@ export interface OutputOptions {
 		define?: string;
 		id?: string;
 	};
-	assetFileNames?: string;
+	assetFileNames?: string | ((chunkInfo: PreRenderedAsset) => string);
 	banner?: string | (() => string | Promise<string>);
-	chunkFileNames?: string;
+	chunkFileNames?: string | ((chunkInfo: PreRenderedChunk) => string);
 	compact?: boolean;
 	// only required for bundle.write
 	dir?: string;
 	/** @deprecated Use the "renderDynamicImport" plugin hook instead. */
 	dynamicImportFunction?: string;
-	entryFileNames?: string;
+	entryFileNames?: string | ((chunkInfo: PreRenderedChunk) => string);
 	esModule?: boolean;
 	exports?: 'default' | 'named' | 'none' | 'auto';
 	extend?: boolean;
@@ -592,14 +592,14 @@ export interface NormalizedOutputOptions {
 		define: string;
 		id?: string;
 	};
-	assetFileNames: string;
+	assetFileNames: string | ((chunkInfo: PreRenderedAsset) => string);
 	banner: () => string | Promise<string>;
-	chunkFileNames: string;
+	chunkFileNames: string | ((chunkInfo: PreRenderedChunk) => string);
 	compact: boolean;
 	dir: string | undefined;
 	/** @deprecated Use the "renderDynamicImport" plugin hook instead. */
 	dynamicImportFunction: string | undefined;
-	entryFileNames: string;
+	entryFileNames: string | ((chunkInfo: PreRenderedChunk) => string);
 	esModule: boolean;
 	exports: 'default' | 'named' | 'none' | 'auto';
 	extend: boolean;
@@ -642,12 +642,16 @@ export interface SerializedTimings {
 	[label: string]: [number, number, number];
 }
 
-export interface OutputAsset {
+export interface PreRenderedAsset {
+	name: string | undefined;
+	source: string | Uint8Array;
+	type: 'asset';
+}
+
+export interface OutputAsset extends PreRenderedAsset {
 	fileName: string;
 	/** @deprecated Accessing "isAsset" on files in the bundle is deprecated, please use "type === \'asset\'" instead */
 	isAsset: true;
-	source: string | Uint8Array;
-	type: 'asset';
 }
 
 export interface RenderedModule {
@@ -658,17 +662,11 @@ export interface RenderedModule {
 }
 
 export interface PreRenderedChunk {
-	code?: string;
-	dynamicImports: string[];
 	exports: string[];
 	facadeModuleId: string | null;
-	fileName?: string;
-	implicitlyLoadedBefore: string[];
-	imports: string[];
 	isDynamicEntry: boolean;
 	isEntry: boolean;
 	isImplicitEntry: boolean;
-	map?: SourceMap;
 	modules: {
 		[id: string]: RenderedModule;
 	};
@@ -677,13 +675,16 @@ export interface PreRenderedChunk {
 }
 
 export interface RenderedChunk extends PreRenderedChunk {
+	code?: string;
+	dynamicImports: string[];
 	fileName: string;
+	implicitlyLoadedBefore: string[];
+	imports: string[];
+	map?: SourceMap;
 }
 
 export interface OutputChunk extends RenderedChunk {
 	code: string;
-	map?: SourceMap;
-	type: 'chunk';
 }
 
 export interface SerializablePluginCache {

src/utils/FileEmitter.ts

@@ -6,6 +6,7 @@ import {
 	FilePlaceholder,
 	NormalizedInputOptions,
 	OutputBundleWithPlaceholders,
+	PreRenderedAsset,
 	WarningHandler
 } from '../rollup/types';
 import { BuildPhase } from './buildPhase';
@@ -28,7 +29,7 @@ import { isPlainPathFragment } from './relativeId';
 import { makeUnique, renderNamePattern } from './renderNamePattern';
 
 interface OutputSpecificFileData {
-	assetFileNames: string;
+	assetFileNames: string | ((assetInfo: PreRenderedAsset) => string);
 	bundle: OutputBundleWithPlaceholders;
 }
 
@@ -39,18 +40,23 @@ function generateAssetFileName(
 ): string {
 	const emittedName = name || 'asset';
 	return makeUnique(
-		renderNamePattern(output.assetFileNames, 'output.assetFileNames', {
-			hash() {
-				const hash = createHash();
-				hash.update(emittedName);
-				hash.update(':');
-				hash.update(source);
-				return hash.digest('hex').substr(0, 8);
+		renderNamePattern(
+			output.assetFileNames,
+			'output.assetFileNames',
+			{
+				hash() {
+					const hash = createHash();
+					hash.update(emittedName);
+					hash.update(':');
+					hash.update(source);
+					return hash.digest('hex').substr(0, 8);
+				},
+				ext: () => extname(emittedName).substr(1),
+				extname: () => extname(emittedName),
+				name: () => emittedName.substr(0, emittedName.length - extname(emittedName).length)
 			},
-			ext: () => extname(emittedName).substr(1),
-			extname: () => extname(emittedName),
-			name: () => emittedName.substr(0, emittedName.length - extname(emittedName).length)
-		}),
+			() => ({ name, source, type: 'asset' })
+		),
 		output.bundle
 	);
 }
@@ -228,7 +234,7 @@ export class FileEmitter {
 
 	public setOutputBundle = (
 		outputBundle: OutputBundleWithPlaceholders,
-		assetFileNames: string,
+		assetFileNames: string | ((assetInfo: PreRenderedAsset) => string),
 		facadeChunkByModule: Map<Module, Chunk>
 	): void => {
 		this.output = {
@@ -334,6 +340,7 @@ export class FileEmitter {
 		const options = this.options;
 		output.bundle[fileName] = {
 			fileName,
+			name: consumedFile.name,
 			get isAsset(): true {
 				warnDeprecation(
 					'Accessing "isAsset" on files in the bundle is deprecated, please use "type === \'asset\'" instead',