feat: OutputBundle Tagged union with 'type = chunk|asset'

.eslintignore

@@ -1,3 +1,4 @@
 test/*/samples/**/*.js
 !test/*/samples/**/_config.js
 test/leak/index.js
+**/*.ts

cli/run/build.ts

@@ -1,7 +1,7 @@
 import ms from 'pretty-ms';
 import tc from 'turbocolor';
 import * as rollup from '../../src/node-entry';
-import { InputOptions, OutputAsset, OutputChunk, OutputOptions, RollupBuild, SourceMap } from '../../src/rollup/types';
+import { InputOptions, OutputOptions, RollupBuild, SourceMap } from '../../src/rollup/types';
 import relativeId from '../../src/utils/relativeId';
 import { handleError, stderr } from '../logging';
 import SOURCEMAPPING_URL from '../sourceMappingUrl';
@@ -49,12 +49,12 @@ export default function build(
 				return bundle.generate(output).then(({ output: outputs }) => {
 					for (const file of outputs) {
 						let source: string | Buffer;
-						if ((file as OutputAsset).isAsset) {
-							source = (file as OutputAsset).source;
+						if (file.type === 'asset') {
+							source = file.source;
 						} else {
-							source = (file as OutputChunk).code;
+							source = file.code;
 							if (output.sourcemap === 'inline') {
-								source += `\n//# ${SOURCEMAPPING_URL}=${((file as OutputChunk)
+								source += `\n//# ${SOURCEMAPPING_URL}=${(file
 									.map as SourceMap).toUrl()}\n`;
 							}
 						}

docs/02-javascript-api.md

@@ -25,12 +25,12 @@ async function build() {
   const { output } = await bundle.generate(outputOptions);
 
   for (const chunkOrAsset of output) {
-    if (chunkOrAsset.isAsset) {
+    if (chunkOrAsset.type === 'asset') {
       // For assets, this contains
       // {
-      //   isAsset: true,                 // signifies that this is an asset
       //   fileName: string,              // the asset file name
       //   source: string | Buffer        // the asset source
+      //   type: 'asset'                  // signifies that this is an asset
       // }
       console.log('Asset', chunkOrAsset);
     } else {
@@ -54,6 +54,7 @@ async function build() {
       //     };
       //   },
       //   name: string                   // the name of this chunk as used in naming patterns
+      //   type: 'chunk',                 // signifies that this is a chunk
       // }
       console.log('Chunk', chunkOrAsset.modules);
     }

docs/05-plugin-development.md

@@ -123,8 +123,8 @@ Called at the end of `bundle.generate()` or immediately before the files are wri
 // AssetInfo
 {
   fileName: string,
-  isAsset: true,
-  source: string | Buffer
+  source: string | Buffer,
+  type: 'asset',
 }
 
 // ChunkInfo
@@ -146,7 +146,8 @@ Called at the end of `bundle.generate()` or immediately before the files are wri
       originalLength: number
     },
   },
-  name: string
+  name: string,
+  type: 'chunk',
 }
 ```
 

src/rollup/index.ts

@@ -168,7 +168,8 @@ function assignChunksToBundle(
 			modules: chunk.renderedModules,
 			get name() {
 				return chunk.getChunkName();
-			}
+			},
+			type: 'chunk'
 		} as OutputChunk;
 	}
 	return outputBundle as OutputBundle;
@@ -301,7 +302,7 @@ export default async function rollup(rawInputOptions: GenericConfigObject): Prom
 				let chunkCnt = 0;
 				for (const fileName of Object.keys(bundle)) {
 					const file = bundle[fileName];
-					if ((file as OutputAsset).isAsset) continue;
+					if (file.type === 'asset') continue;
 					chunkCnt++;
 					if (chunkCnt > 1) break;
 				}
@@ -343,10 +344,10 @@ enum SortingFileType {
 }
 
 function getSortingFileType(file: OutputAsset | OutputChunk): SortingFileType {
-	if ((file as OutputAsset).isAsset) {
+	if (file.type === 'asset') {
 		return SortingFileType.ASSET;
 	}
-	if ((file as OutputChunk).isEntry) {
+	if (file.isEntry) {
 		return SortingFileType.ENTRY_CHUNK;
 	}
 	return SortingFileType.SECONDARY_CHUNK;
@@ -367,10 +368,6 @@ function createOutput(outputBundle: Record<string, OutputChunk | OutputAsset | {
 	};
 }
 
-function isOutputAsset(file: OutputAsset | OutputChunk): file is OutputAsset {
-	return (file as OutputAsset).isAsset === true;
-}
-
 function writeOutputFile(
 	graph: Graph,
 	build: RollupBuild,
@@ -383,7 +380,7 @@ function writeOutputFile(
 	);
 	let writeSourceMapPromise: Promise<void>;
 	let source: string | Buffer;
-	if (isOutputAsset(outputFile)) {
+	if (outputFile.type === 'asset') {
 		source = outputFile.source;
 	} else {
 		source = outputFile.code;
@@ -403,7 +400,7 @@ function writeOutputFile(
 		.then(() => writeSourceMapPromise)
 		.then(
 			(): any =>
-				!isOutputAsset(outputFile) &&
+				outputFile.type === 'chunk' &&
 				graph.pluginDriver.hookSeq('onwrite', [
 					{
 						bundle: build,

src/rollup/types.d.ts

@@ -314,8 +314,12 @@ export interface OutputBundle {
 	[fileName: string]: OutputAsset | OutputChunk;
 }
 
+export interface FilePlaceholder {
+	type: 'placeholder';
+}
+
 export interface OutputBundleWithPlaceholders {
-	[fileName: string]: OutputAsset | OutputChunk | {};
+	[fileName: string]: OutputAsset | OutputChunk | FilePlaceholder;
 }
 
 interface OnGenerateOptions extends OutputOptions {
@@ -487,10 +491,11 @@ export interface SerializedTimings {
 }
 
 export interface OutputAsset {
-	code?: undefined;
 	fileName: string;
+	/** @deprecated Accessing "isAsset" on files in the bundle is deprecated, please use "type === \'asset\'" instead */
 	isAsset: true;
 	source: string | Buffer;
+	type: 'asset';
 }
 
 export interface RenderedModule {
@@ -520,6 +525,7 @@ export interface RenderedChunk extends PreRenderedChunk {
 export interface OutputChunk extends RenderedChunk {
 	code: string;
 	map?: SourceMap;
+	type: 'chunk';
 }
 
 export interface SerializablePluginCache {

src/utils/FileEmitter.ts

@@ -2,7 +2,7 @@ import sha256 from 'hash.js/lib/hash/sha/256';
 import Chunk from '../Chunk';
 import Graph from '../Graph';
 import Module from '../Module';
-import { OutputAsset, OutputBundleWithPlaceholders } from '../rollup/types';
+import { FilePlaceholder, OutputBundleWithPlaceholders } from '../rollup/types';
 import { BuildPhase } from './buildPhase';
 import {
 	errAssetNotFinalisedForFileName,
@@ -78,8 +78,8 @@ interface EmittedFile {
 
 type ConsumedFile = ConsumedChunk | ConsumedAsset;
 
-export const FILE_PLACEHOLDER = {
-	isPlaceholder: true
+export const FILE_PLACEHOLDER: FilePlaceholder = {
+	type: 'placeholder'
 };
 
 function hasValidType(
@@ -318,17 +318,30 @@ export class FileEmitter {
 		// We must not modify the original assets to avoid interaction between outputs
 		const assetWithFileName = { ...consumedFile, source, fileName };
 		this.filesByReferenceId.set(referenceId, assetWithFileName);
-		output.bundle[fileName] = { fileName, isAsset: true, source };
+		const graph = this.graph;
+		output.bundle[fileName] = {
+			fileName,
+			get isAsset(): true {
+				graph.warnDeprecation(
+					'Accessing "isAsset" on files in the bundle is deprecated, please use "type === \'asset\'" instead',
+					false
+				);
+
+				return true;
+			},
+			source,
+			type: 'asset'
+		};
 	}
 
 	private findExistingAssetFileNameWithSource(
 		bundle: OutputBundleWithPlaceholders,
 		source: string | Buffer
 	): string | null {
 		for (const fileName of Object.keys(bundle)) {
-			const outputFile = bundle[fileName] as OutputAsset;
+			const outputFile = bundle[fileName];
 			if (
-				outputFile.isAsset &&
+				outputFile.type === 'asset' &&
 				(Buffer.isBuffer(source) && Buffer.isBuffer(outputFile.source)
 					? source.equals(outputFile.source)
 					: source === outputFile.source)

test/form/samples/deprecated/emit-asset/_config.js

@@ -1,5 +1,6 @@
 const fs = require('fs');
 const path = require('path');
+const assert = require('assert');
 
 module.exports = {
 	description: 'supports emitting assets from plugin hooks',
@@ -18,6 +19,20 @@ module.exports = {
 						fs.readFileSync(id)
 					)};`;
 				}
+			},
+			generateBundle(options, outputBundle) {
+				const keys = Object.keys(outputBundle);
+				assert.strictEqual(keys.length, 2);
+				assert.strictEqual(keys[0], 'assets/logo-25585ac1.svg');
+				const asset = outputBundle[keys[0]];
+				assert.strictEqual(asset.fileName, 'assets/logo-25585ac1.svg');
+				assert.strictEqual(asset.isAsset, true);
+				assert.strictEqual(asset.type, 'asset');
+				assert.ok(
+					asset.source.equals(fs.readFileSync(path.resolve(__dirname, 'logo.svg'))),
+					'asset has correct source'
+				);
+				assert.ok(keys[1].endsWith('.js'), `${keys[1]} ends with ".js"`);
 			}
 		}
 	}

test/form/samples/emit-asset-file/_config.js

@@ -26,7 +26,7 @@ module.exports = {
 				assert.strictEqual(keys[0], 'assets/logo-25585ac1.svg');
 				const asset = outputBundle[keys[0]];
 				assert.strictEqual(asset.fileName, 'assets/logo-25585ac1.svg');
-				assert.strictEqual(asset.isAsset, true);
+				assert.strictEqual(asset.type, 'asset');
 				assert.ok(
 					asset.source.equals(fs.readFileSync(path.resolve(__dirname, 'logo.svg'))),
 					'asset has correct source'