Adds type definitions for RollupWatcher events. (#3302)

* Adds type definitions for RollupWatcher events.

The type information is extracted from https://github.com/rollup/rollup/blob/master/src/watch/index.ts, someone should double check that I got it all right.  I'm new to rollup and have never actually used any of this stuff, but when I tried to I ran into the problem of there being no useful type information which caused me to have to read source code.  Rather than having everyone suffer like I did, I decided to create a PR to resolve the issue.

* Fixes RollupWatcher.on type signature.

I didn't realize that `on` was chainable, this should resolve the issue.

* Utilize new watcher type

* Remove FATAL references

Co-authored-by: Micah Zoltu <micah@zoltu.net>
Co-authored-by: Andrew Powell <shellscape@users.noreply.github.com>

cli/run/watch.ts

@@ -5,13 +5,9 @@ import onExit from 'signal-exit';
 import tc from 'turbocolor';
 import * as rollup from '../../src/node-entry';
 import {
-	InputOption,
-	RollupBuild,
-	RollupError,
 	RollupWatcher,
 	RollupWatchOptions,
-	WarningHandler,
-	WatcherOptions
+	WarningHandler
 } from '../../src/rollup/types';
 import mergeOptions, { GenericConfigObject } from '../../src/utils/mergeOptions';
 import relativeId from '../../src/utils/relativeId';
@@ -21,15 +17,6 @@ import loadConfigFile from './loadConfigFile';
 import { getResetScreen } from './resetScreen';
 import { printTimings } from './timings';
 
-interface WatchEvent {
-	code?: string;
-	duration?: number;
-	error?: RollupError | Error;
-	input?: InputOption;
-	output?: string[];
-	result?: RollupBuild;
-}
-
 export default function watch(
 	configFile: string,
 	configs: GenericConfigObject[],
@@ -40,7 +27,7 @@ export default function watch(
 	const warnings = batchWarnings();
 	const initialConfigs = processConfigs(configs);
 	const clearScreen = initialConfigs.every(
-		config => (config.watch as WatcherOptions).clearScreen !== false
+		config => config.watch!.clearScreen !== false
 	);
 
 	const resetScreen = getResetScreen(isTTY && clearScreen);
@@ -75,16 +62,11 @@ export default function watch(
 	function start(configs: RollupWatchOptions[]) {
 		watcher = rollup.watch(configs as any);
 
-		watcher.on('event', (event: WatchEvent) => {
+		watcher.on('event', event => {
 			switch (event.code) {
-				case 'FATAL':
-					handleError(event.error as RollupError, true);
-					process.exit(1);
-					break;
-
 				case 'ERROR':
 					warnings.flush();
-					handleError(event.error as RollupError, true);
+					handleError(event.error, true);
 					break;
 
 				case 'START':
@@ -106,7 +88,7 @@ export default function watch(
 						stderr(
 							tc.cyan(
 								`bundles ${tc.bold(input)} → ${tc.bold(
-									(event.output as string[]).map(relativeId).join(', ')
+									event.output.map(relativeId).join(', ')
 								)}...`
 							)
 						);
@@ -119,8 +101,8 @@ export default function watch(
 						stderr(
 							tc.green(
 								`created ${tc.bold(
-									(event.output as string[]).map(relativeId).join(', ')
-								)} in ${tc.bold(ms(event.duration as number))}`
+									event.output.map(relativeId).join(', ')
+								)} in ${tc.bold(ms(event.duration))}`
 							)
 						);
 					if (event.result && event.result.getTimings) {
@@ -204,6 +186,6 @@ export default function watch(
 
 		configWatcher = fs.watch(configFile, (event: string) => {
 			if (event === 'change') restart();
-		});
+		}) as RollupWatcher;
 	}
 }

docs/02-javascript-api.md

@@ -117,7 +117,7 @@ const outputOptions = {
   globals,
   name,
   plugins,
-  
+
   // advanced output options
   assetFileNames,
   banner,
@@ -135,7 +135,7 @@ const outputOptions = {
   sourcemapExcludeSources,
   sourcemapFile,
   sourcemapPathTransform,
-  
+
   // danger zone
   amd,
   dynamicImportFunction,
@@ -167,7 +167,6 @@ watcher.on('event', event => {
   //   BUNDLE_END   — finished building a bundle
   //   END          — finished building all bundles
   //   ERROR        — encountered an error while bundling
-  //   FATAL        — encountered an unrecoverable error
 });
 
 // stop watching

src/rollup/index.ts

@@ -401,7 +401,8 @@ function createOutput(outputBundle: Record<string, OutputChunk | OutputAsset | {
 			.map(fileName => outputBundle[fileName])
 			.filter(outputFile => Object.keys(outputFile).length > 0) as (
 			| OutputChunk
-			| OutputAsset)[]).sort((outputFileA, outputFileB) => {
+			| OutputAsset
+		)[]).sort((outputFileA, outputFileB) => {
 			const fileTypeA = getSortingFileType(outputFileA);
 			const fileTypeB = getSortingFileType(outputFileB);
 			if (fileTypeA === fileTypeB) return 0;

src/rollup/types.d.ts

@@ -614,7 +614,43 @@ export interface RollupWatchOptions extends InputOptions {
 	watch?: WatcherOptions;
 }
 
-export interface RollupWatcher extends EventEmitter {
+interface TypedEventEmitter<T> {
+	addListener<K extends keyof T>(event: K, listener: T[K]): this;
+	emit<K extends keyof T>(event: K, ...args: any[]): boolean;
+	eventNames(): Array<keyof T>;
+	getMaxListeners(): number;
+	listenerCount(type: keyof T): number;
+	listeners<K extends keyof T>(event: K): Array<T[K]>;
+	off<K extends keyof T>(event: K, listener: T[K]): this;
+	on<K extends keyof T>(event: K, listener: T[K]): this;
+	once<K extends keyof T>(event: K, listener: T[K]): this;
+	prependListener<K extends keyof T>(event: K, listener: T[K]): this;
+	prependOnceListener<K extends keyof T>(event: K, listener: T[K]): this;
+	rawListeners<K extends keyof T>(event: K): Array<T[K]>;
+	removeAllListeners<K extends keyof T>(event?: K): this;
+	removeListener<K extends keyof T>(event: K, listener: T[K]): this;
+	setMaxListeners(n: number): this;
+}
+
+export type RollupWatcherEvent =
+	| { code: 'START' }
+	| { code: 'BUNDLE_START'; input: InputOption; output: readonly string[] }
+	| {
+			code: 'BUNDLE_END';
+			duration: number;
+			input: InputOption;
+			output: readonly string[];
+			result: RollupBuild;
+	  }
+	| { code: 'END' }
+	| { code: 'ERROR'; error: RollupError };
+
+export interface RollupWatcher
+	extends TypedEventEmitter<{
+		change: (id: string) => void;
+		event: (event: RollupWatcherEvent) => void;
+		restart: () => void;
+	}> {
 	close(): void;
 }
 

src/utils/PluginContext.ts

@@ -194,7 +194,7 @@ export function getPluginContexts(
 								});
 								deprecationWarningShown = true;
 							}
-							return watcher!.on(event, handler);
+							return watcher!.on(event as any, handler);
 						}
 
 						return {

src/utils/deconflictChunk.ts

@@ -97,9 +97,10 @@ function deconflictImportsOther(
 			if (chunk.exportMode === 'default' || (preserveModules && variable.isNamespace)) {
 				variable.setRenderNames(null, chunk.variableName);
 			} else {
-				variable.setRenderNames(chunk.variableName, chunk.getVariableExportName(variable) as
-					| string
-					| null);
+				variable.setRenderNames(
+					chunk.variableName,
+					chunk.getVariableExportName(variable) as string | null
+				);
 			}
 		}
 	}

src/watch/index.ts

@@ -28,7 +28,7 @@ export class Watcher {
 	private tasks: Task[];
 
 	constructor(configs: GenericConfigObject[] | GenericConfigObject) {
-		this.emitter = new (class extends EventEmitter implements RollupWatcher {
+		this.emitter = new (class extends EventEmitter {
 			close: () => void;
 			constructor(close: () => void) {
 				super();
@@ -37,7 +37,7 @@ export class Watcher {
 				// showing the `MaxListenersExceededWarning` to the user.
 				this.setMaxListeners(Infinity);
 			}
-		})(this.close.bind(this));
+		})(this.close.bind(this)) as RollupWatcher;
 		this.tasks = (Array.isArray(configs) ? configs : configs ? [configs] : []).map(
 			config => new Task(this, config)
 		);
@@ -55,7 +55,7 @@ export class Watcher {
 	}
 
 	emit(event: string, value?: any) {
-		this.emitter.emit(event, value);
+		this.emitter.emit(event as any, value);
 	}
 
 	invalidate(id?: string) {

test/function/samples/preserve-modules/virtual-modules-conflict/_config.js

@@ -22,11 +22,14 @@ module.exports = {
 		]
 	},
 	bundle(bundle) {
-		return bundle.generate({ format: 'esm' }).then(generated =>
-			assert.deepEqual(
-				generated.output.map(chunk => chunk.fileName),
-				['main.js', '_virtual/_virtualModule.js', '_virtual/_virtualModule2.js']
-			)
-		);
+		return bundle
+			.generate({ format: 'esm' })
+			.then(generated =>
+				assert.deepEqual(generated.output.map(chunk => chunk.fileName), [
+					'main.js',
+					'_virtual/_virtualModule.js',
+					'_virtual/_virtualModule2.js'
+				])
+			);
 	}
 };

test/function/samples/preserve-modules/virtual-modules/_config.js

@@ -22,11 +22,14 @@ module.exports = {
 		]
 	},
 	bundle(bundle) {
-		return bundle.generate({ format: 'esm' }).then(generated =>
-			assert.deepEqual(
-				generated.output.map(chunk => chunk.fileName),
-				['main.js', '_virtual/_virtualModule', 'lib/lib.js']
-			)
-		);
+		return bundle
+			.generate({ format: 'esm' })
+			.then(generated =>
+				assert.deepEqual(generated.output.map(chunk => chunk.fileName), [
+					'main.js',
+					'_virtual/_virtualModule',
+					'lib/lib.js'
+				])
+			);
 	}
 };

test/hooks/index.js

@@ -914,7 +914,7 @@ describe('hooks', () => {
 		return new Promise((resolve, reject) => {
 			watcher.on('event', event => {
 				if (event.code === 'BUNDLE_END') resolve();
-				else if (event.code === 'ERROR' || event.code === 'FATAL') reject(event.error);
+				else if (event.code === 'ERROR') reject(event.error);
 			});
 		}).catch(err => {
 			assert.strictEqual(
@@ -1192,7 +1192,10 @@ describe('hooks', () => {
 					})
 				)
 				.then(() => {
-					assert.deepEqual(result, [{ a: file, format: 'cjs' }, { b: file, format: 'cjs' }]);
+					assert.deepEqual(result, [
+						{ a: file, format: 'cjs' },
+						{ b: file, format: 'cjs' }
+					]);
 					return sander.rimraf(TEMP_DIR);
 				});
 		});

test/watch/index.js

@@ -34,9 +34,6 @@ describe('rollup.watch', () => {
 				} else if (typeof next === 'string') {
 					watcher.once('event', event => {
 						if (event.code !== next) {
-							if (event.code === 'FATAL') {
-								console.error(event.error);
-							}
 							watcher.close();
 							if (event.code === 'ERROR') console.log(event.error);
 							reject(new Error(`Expected ${next} event, got ${event.code}`));