Rename esm to es everywhere, add systemjs alias (#3381)

build-plugins/fix-acorn-esm-import.js → build-plugins/fix-acorn-es-import.js

@@ -3,11 +3,11 @@ const newAcornImport = "import * as acorn from 'acorn';\nimport { Parser } from
 
 // by default, rollup-plugin-commonjs will translate require statements as default imports
 // which can cause issues for secondary tools that use the ESM version of acorn
-export default function fixAcornEsmImport() {
+export default function fixAcornEsImport() {
 	let found = false;
 
 	return {
-		name: 'fix-acorn-esm-import',
+		name: 'fix-acorn-es-import',
 		renderChunk(code) {
 			return code.replace(expectedAcornImport, () => {
 				found = true;

cli/help.md

@@ -9,7 +9,7 @@ Basic options:
                               is unspecified, defaults to rollup.config.js)
 -d, --dir <dirname>         Directory for chunks (if absent, prints to stdout)
 -e, --external <ids>        Comma-separate list of module IDs to exclude
--f, --format <format>       Type of output (amd, cjs, esm, iife, umd)
+-f, --format <format>       Type of output (amd, cjs, es, iife, umd, system)
 -g, --globals <pairs>       Comma-separate list of `moduleID:Global` pairs
 -h, --help                  Show this help message
 -i, --input <filename>      Input (alternative to <entry file>)

docs/00-introduction.md

@@ -86,4 +86,4 @@ Rollup can import existing CommonJS modules [through a plugin](https://github.co
 
 #### Publishing ES Modules
 
-To make sure your ES modules are immediately usable by tools that work with CommonJS such as Node.js and webpack, you can use Rollup to compile to UMD or CommonJS format, and then point to that compiled version with the `main` property in your `package.json` file. If your `package.json` file also has a `module` field, ESM-aware tools like Rollup and [webpack 2+](https://webpack.js.org/) will [import the ES module version](https://github.com/rollup/rollup/wiki/pkg.module) directly.
+To make sure your ES modules are immediately usable by tools that work with CommonJS such as Node.js and webpack, you can use Rollup to compile to UMD or CommonJS format, and then point to that compiled version with the `main` property in your `package.json` file. If your `package.json` file also has a `module` field, ES-module-aware tools like Rollup and [webpack 2+](https://webpack.js.org/) will [import the ES module version](https://github.com/rollup/rollup/wiki/pkg.module) directly.

docs/01-command-line-reference.md

@@ -128,7 +128,7 @@ export default [{
     },
     {
       file: 'dist/bundle-b2.js',
-      format: 'esm'
+      format: 'es'
     }
   ]
 }];
@@ -213,7 +213,7 @@ Many options have command line equivalents. In those cases, any arguments passed
                               is unspecified, defaults to rollup.config.js)
 -d, --dir <dirname>         Directory for chunks (if absent, prints to stdout)
 -e, --external <ids>        Comma-separate list of module IDs to exclude
--f, --format <format>       Type of output (amd, cjs, esm, iife, umd)
+-f, --format <format>       Type of output (amd, cjs, es, iife, umd, system)
 -g, --globals <pairs>       Comma-separate list of `moduleID:Global` pairs
 -h, --help                  Show this help message
 -i, --input <filename>      Input (alternative to <entry file>)

docs/04-tutorial.md

@@ -378,7 +378,7 @@ Notice how both entry points import the same shared chunk. Rollup will never dup
 
 You can build the same code for the browser via native ES modules, an AMD loader or SystemJS.
 
-For example, with `-f esm` for native modules:
+For example, with `-f es` for native modules:
 
 ```
 rollup src/main.js src/main2.js -f esm -d dist

docs/05-plugin-development.md

@@ -580,7 +580,7 @@ document.body.appendChild(image);
 
 Similar to assets, emitted chunks can be referenced from within JS code via `import.meta.ROLLUP_FILE_URL_referenceId` as well.
 
-The following example will detect imports prefixed with `register-paint-worklet:` and generate the necessary code and separate chunk to generate a CSS paint worklet. Note that this will only work in modern browsers and will only work if the output format is set to `esm`.
+The following example will detect imports prefixed with `register-paint-worklet:` and generate the necessary code and separate chunk to generate a CSS paint worklet. Note that this will only work in modern browsers and will only work if the output format is set to `es`.
 
 ```js
 // plugin

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

@@ -91,21 +91,21 @@ export default {
 When using the command line interface, multiple inputs can be provided by using the option multiple times. When provided as the first options, it is equivalent to not prefix them with `--input`:
 
 ```sh
-rollup --format esm --input src/entry1.js --input src/entry2.js
+rollup --format es --input src/entry1.js --input src/entry2.js
 # is equivalent to
-rollup src/entry1.js src/entry2.js --format esm
+rollup src/entry1.js src/entry2.js --format es
 ```
 
 Chunks can be named by adding an `=` to the provided value:
 
 ```sh
-rollup main=src/entry1.js other=src/entry2.js --format esm
+rollup main=src/entry1.js other=src/entry2.js --format es
 ```
 
 File names containing spaces can be specified by using quotes:
 
 ```sh
-rollup "main entry"="src/entry 1.js" "src/other entry.js" --format esm
+rollup "main entry"="src/entry 1.js" "src/other entry.js" --format es
 ```
 
 #### output.dir
@@ -128,7 +128,7 @@ Specifies the format of the generated bundle. One of the following:
 
 * `amd` – Asynchronous Module Definition, used with module loaders like RequireJS
 * `cjs` – CommonJS, suitable for Node and other bundlers
-* `esm` – Keep the bundle as an ES module file, suitable for other bundlers and inclusion as a `<script type=module>` tag in modern browsers
+* `es` – Keep the bundle as an ES module file, suitable for other bundlers and inclusion as a `<script type=module>` tag in modern browsers
 * `iife` – A self-executing function, suitable for inclusion as a `<script>` tag. (If you want to create a bundle for your application, you probably want to use this.)
 * `umd` – Universal Module Definition, works as `amd`, `cjs` and `iife` all in one
 * `system` – Native format of the SystemJS loader
@@ -244,11 +244,11 @@ export default {
   output: [
     {
       file: 'bundle.js',
-      format: 'esm'
+      format: 'es'
     },
     {
       file: 'bundle.min.js',
-      format: 'esm',
+      format: 'es',
       plugins: [terser()]
     }
   ]
@@ -428,7 +428,7 @@ 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:
- * `[format]`: The rendering format defined in the output options, e.g. `esm` or `cjs`.
+ * `[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 [`manualChunks`](guide/en/#manualchunks) 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.
 
@@ -447,7 +447,7 @@ CLI: `--entryFileNames <pattern>`<br>
 Default: `"[name].js"`
 
 The pattern to use for chunks created from entry points. Pattern supports the following placeholders:
-* `[format]`: The rendering format defined in the output options, e.g. `esm` or `cjs`.
+* `[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.
 
@@ -566,7 +566,7 @@ export default ({
       // will transform e.g. "src/main.js" -> "main.js"
       return path.relative('src', relativePath)
     },
-    format: 'esm',
+    format: 'es',
     sourcemap: true
   }]
 });
@@ -717,7 +717,7 @@ Type: `boolean`<br>
 CLI: `--esModule`/`--no-esModule`
 Default: `true`
 
-Whether or not to add a `__esModule: true` property when generating exports for non-ESM formats.
+Whether or not to add a `__esModule: true` property when generating exports for non-ES formats.
 
 #### output.exports
 Type: `string`<br>
@@ -846,14 +846,14 @@ Type: `boolean`<br>
 CLI: `--strict`/`--no-strict`<br>
 Default: `true`
 
-Whether to include the 'use strict' pragma at the top of generated non-ESM bundles. Strictly speaking, ES modules are *always* in strict mode, so you shouldn't disable this without good reason.
+Whether to include the 'use strict' pragma at the top of generated non-ES bundles. Strictly speaking, ES modules are *always* in strict mode, so you shouldn't disable this without good reason.
 
 #### output.dynamicImportFunction
 Type: `string`<br>
 CLI: `--dynamicImportFunction <name>`<br>
 Default: `import`
 
-This will rename the dynamic import function to the chosen name when outputting ESM bundles. This is useful for generating code that uses a dynamic import polyfill such as [this one](https://github.com/uupaa/dynamic-import-polyfill).
+This will rename the dynamic import function to the chosen name when outputting ES bundles. This is useful for generating code that uses a dynamic import polyfill such as [this one](https://github.com/uupaa/dynamic-import-polyfill).
 
 #### preserveSymlinks
 Type: `boolean`<br>

rollup.config.js

@@ -10,7 +10,7 @@ import { terser } from 'rollup-plugin-terser';
 import typescript from 'rollup-plugin-typescript';
 import addBinShebang from './build-plugins/add-bin-shebang';
 import conditionalFsEventsImport from './build-plugins/conditional-fsevents-import';
-import fixAcornEsmImport from './build-plugins/fix-acorn-esm-import';
+import fixAcornEsImport from './build-plugins/fix-acorn-es-import.js';
 import generateLicenseFile from './build-plugins/generate-license-file';
 import pkg from './package.json';
 
@@ -117,10 +117,10 @@ export default command => {
 
 	const esmBuild = Object.assign({}, commonJSBuild, {
 		input: { 'rollup.es.js': 'src/node-entry.ts' },
-		plugins: [...nodePlugins, fixAcornEsmImport()],
+		plugins: [...nodePlugins, fixAcornEsImport()],
 		output: Object.assign({}, commonJSBuild.output, {
 			chunkFileNames: 'shared-es/[name].js',
-			format: 'esm',
+			format: 'es',
 			sourcemap: false
 		})
 	});
@@ -146,7 +146,7 @@ export default command => {
 		treeshake,
 		output: [
 			{ file: 'dist/rollup.browser.js', format: 'umd', name: 'rollup', banner },
-			{ file: 'dist/rollup.browser.es.js', format: 'esm', banner }
+			{ file: 'dist/rollup.browser.es.js', format: 'es', banner }
 		]
 	};
 

src/Chunk.ts

@@ -263,7 +263,7 @@ export default class Chunk {
 				: [options.chunkFileNames || '[name]-[hash].js', 'output.chunkFileNames'];
 		return makeUnique(
 			renderNamePattern(pattern, patternName, {
-				format: () => (options.format === 'es' ? 'esm' : (options.format as string)),
+				format: () => options.format as string,
 				hash: () =>
 					includeHash
 						? this.computeContentHashWithDependencies(
@@ -298,7 +298,7 @@ export default class Chunk {
 				{
 					ext: () => extension.substr(1),
 					extname: () => extension,
-					format: () => (options.format === 'es' ? 'esm' : (options.format as string)),
+					format: () => options.format as string,
 					name: () => this.getChunkName()
 				}
 			);
@@ -634,7 +634,7 @@ export default class Chunk {
 		if (options.dynamicImportFunction && format !== 'es') {
 			this.graph.warn({
 				code: 'INVALID_OPTION',
-				message: '"output.dynamicImportFunction" is ignored for formats other than "esm".'
+				message: '"output.dynamicImportFunction" is ignored for formats other than "es".'
 			});
 		}
 

src/finalisers/esm.ts → src/finalisers/es.ts

@@ -3,7 +3,7 @@ import { ChunkDependencies, ChunkExports, ImportSpecifier, ReexportSpecifier } f
 import { OutputOptions } from '../rollup/types';
 import { FinaliserOptions } from './index';
 
-export default function esm(
+export default function es(
 	magicString: MagicStringBundle,
 	{ intro, outro, dependencies, exports }: FinaliserOptions,
 	options: OutputOptions

src/finalisers/index.ts

@@ -3,7 +3,7 @@ import { ChunkDependencies, ChunkExports } from '../Chunk';
 import { OutputOptions, RollupWarning } from '../rollup/types';
 import amd from './amd';
 import cjs from './cjs';
-import esm from './esm';
+import es from './es';
 import iife from './iife';
 import system from './system';
 import umd from './umd';
@@ -29,6 +29,6 @@ export type Finaliser = (
 	options: OutputOptions
 ) => MagicStringBundle;
 
-export default { system, amd, cjs, es: esm, iife, umd } as {
+export default { system, amd, cjs, es, iife, umd } as {
 	[format: string]: Finaliser;
 };

src/rollup/rollup.ts

@@ -5,7 +5,7 @@ import Graph from '../Graph';
 import { createAddons } from '../utils/addons';
 import { assignChunkIds } from '../utils/assignChunkIds';
 import commondir from '../utils/commondir';
-import { errCannotEmitFromOptionsHook, errInvalidExportOptionValue, error } from '../utils/error';
+import { errCannotEmitFromOptionsHook, error } from '../utils/error';
 import { writeFile } from '../utils/fs';
 import getExportMode from '../utils/getExportMode';
 import {
@@ -33,19 +33,6 @@ import {
 	WarningHandler
 } from './types';
 
-function checkOutputOptions(options: OutputOptions) {
-	if (['amd', 'cjs', 'system', 'es', 'iife', 'umd'].indexOf(options.format as string) < 0) {
-		return error({
-			message: `You must specify "output.format", which can be one of "amd", "cjs", "system", "esm", "iife" or "umd".`,
-			url: `https://rollupjs.org/guide/en/#output-format`
-		});
-	}
-
-	if (options.exports && !['default', 'named', 'none', 'auto'].includes(options.exports)) {
-		return error(errInvalidExportOptionValue(options.exports));
-	}
-}
-
 function getAbsoluteEntryModulePaths(chunks: Chunk[]): string[] {
 	const absoluteEntryModulePaths: string[] = [];
 	for (const chunk of chunks) {
@@ -391,28 +378,22 @@ function normalizeOutputOptions(
 	hasMultipleChunks: boolean,
 	outputPluginDriver: PluginDriver
 ): OutputOptions {
-	const outputOptionBase = rawOutputOptions.output || inputOptions.output || rawOutputOptions;
-	let outputOptions = parseOutputOptions(
-		outputOptionBase as GenericConfigObject,
+	const outputOptions = parseOutputOptions(
+		outputPluginDriver.hookReduceArg0Sync(
+			'outputOptions',
+			[rawOutputOptions.output || inputOptions.output || rawOutputOptions],
+			(outputOptions: OutputOptions, result: OutputOptions) => result || outputOptions,
+			pluginContext => {
+				const emitError = () => pluginContext.error(errCannotEmitFromOptionsHook());
+				return {
+					...pluginContext,
+					emitFile: emitError,
+					setAssetSource: emitError
+				};
+			}
+		) as GenericConfigObject,
 		inputOptions.onwarn as WarningHandler
 	);
-	const outputOptionsReducer = (outputOptions: OutputOptions, result: OutputOptions) =>
-		result || outputOptions;
-	outputOptions = outputPluginDriver.hookReduceArg0Sync(
-		'outputOptions',
-		[outputOptions],
-		outputOptionsReducer,
-		pluginContext => {
-			const emitError = () => pluginContext.error(errCannotEmitFromOptionsHook());
-			return {
-				...pluginContext,
-				emitFile: emitError,
-				setAssetSource: emitError
-			};
-		}
-	);
-
-	checkOutputOptions(outputOptions);
 
 	if (typeof outputOptions.file === 'string') {
 		if (typeof outputOptions.dir === 'string')

src/rollup/types.d.ts

@@ -418,6 +418,7 @@ export type ModuleFormat =
 	| 'iife'
 	| 'module'
 	| 'system'
+	| 'systemjs'
 	| 'umd';
 
 export type OptionsPaths = Record<string, string> | ((id: string) => string);