Improved watcher hooks

docs/05-plugin-development.md

@@ -92,6 +92,13 @@ Next Hook: [`resolveId`](guide/en/#resolveid) to resolve each entry point in par
 
 Called on each `rollup.rollup` build. This is the recommended hook to use when you need access to the options passed to `rollup.rollup()` as it takes the transformations by all [`options`](guide/en/#options) hooks into account and also contains the right default values for unset options.
 
+#### `closeWatcher`
+Type: `() => void`<br>
+Kind: `sync, sequential`<br>
+Previous/Next Hook: This hook can be triggered at any time both during the build and the output generation phases. If that is the case, the current build will still proceed but no new [`watchChange`](guide/en/#watchChange) events will be triggered ever.
+
+Notifies a plugin when watcher process closes and all open resources should be closed too. This hook cannot be used by output plugins.
+
 #### `load`
 Type: `(id: string) => string | null | {code: string, map?: string | SourceMap, ast? : ESTree.Program, moduleSideEffects?: boolean | "no-treeshake" | null, syntheticNamedExports?: boolean | string | null, meta?: {[plugin: string]: any} | null}`<br>
 Kind: `async, first`<br>
@@ -236,11 +243,12 @@ See [custom module meta-data](guide/en/#custom-module-meta-data) for how to use
 You can use [`this.getModuleInfo`](guide/en/#thisgetmoduleinfomoduleid-string--moduleinfo--null) to find out the previous values of `moduleSideEffects`, `syntheticNamedExports` and `meta` inside this hook.
 
 #### `watchChange`
-Type: `(id: string) => void`<br>
+Type: `(id: string, isDeleted: boolean) => void`<br>
 Kind: `sync, sequential`<br>
 Previous/Next Hook: This hook can be triggered at any time both during the build and the output generation phases. If that is the case, the current build will still proceed but a new build will be scheduled to start once the current build has completed, starting again with [`options`](guide/en/#options).
 
 Notifies a plugin whenever rollup has detected a change to a monitored file in `--watch` mode. This hook cannot be used by output plugins.
+Second argument will be `true` if file deleted.  
 
 ### Output Generation Hooks
 
@@ -655,6 +663,11 @@ During the build, this object represents currently available information about t
 
 Returns `null` if the module id cannot be found.
 
+#### `this.getWatchFiles() => string[]`
+
+Get ids of the files which has been watched previously. Include both files added by plugins with `this.addWatchFile`
+ and files added implicitly by rollup during the build.
+
 #### `this.meta: {rollupVersion: string, watchMode: boolean}`
 
 An object containing potentially useful Rollup metadata:

src/Graph.ts

@@ -84,10 +84,13 @@ export default class Graph {
 
 		if (watcher) {
 			this.watchMode = true;
-			const handleChange = (id: string) => this.pluginDriver.hookSeqSync('watchChange', [id]);
+			const handleChange = (id: string, del: boolean) => this.pluginDriver.hookSeqSync('watchChange', [id, del]);
+			const handleClose = () => this.pluginDriver.hookSeqSync('closeWatcher', []);
 			watcher.on('change', handleChange);
+			watcher.on('close', handleClose);
 			watcher.once('restart', () => {
 				watcher.removeListener('change', handleChange);
+				watcher.removeListener('close', handleClose);
 			});
 		}
 		this.pluginDriver = new PluginDriver(this, options, options.plugins, this.pluginCache);

src/rollup/types.d.ts

@@ -195,6 +195,7 @@ export interface PluginContext extends MinimalPluginContext {
 	getFileName: (fileReferenceId: string) => string;
 	getModuleIds: () => IterableIterator<string>;
 	getModuleInfo: GetModuleInfo;
+	getWatchFiles: () => string[];
 	/** @deprecated Use `this.resolve` instead */
 	isExternal: IsExternal;
 	/** @deprecated Use `this.getModuleIds` instead */
@@ -345,13 +346,14 @@ export interface OutputBundleWithPlaceholders {
 export interface PluginHooks extends OutputPluginHooks {
 	buildEnd: (this: PluginContext, err?: Error) => Promise<void> | void;
 	buildStart: (this: PluginContext, options: NormalizedInputOptions) => Promise<void> | void;
+	closeWatcher: (this: PluginContext) => void;
 	load: LoadHook;
 	moduleParsed: ModuleParsedHook;
 	options: (this: MinimalPluginContext, options: InputOptions) => InputOptions | null | undefined;
 	resolveDynamicImport: ResolveDynamicImportHook;
 	resolveId: ResolveIdHook;
 	transform: TransformHook;
-	watchChange: (id: string) => void;
+	watchChange: (this: PluginContext, id: string, isDeleted: boolean) => void;
 }
 
 interface OutputPluginHooks {
@@ -419,6 +421,7 @@ export type FirstPluginHooks =
 
 export type SequentialPluginHooks =
 	| 'augmentChunkHash'
+	| 'closeWatcher'
 	| 'generateBundle'
 	| 'options'
 	| 'outputOptions'
@@ -816,7 +819,8 @@ export type RollupWatcherEvent =
 
 export interface RollupWatcher
 	extends TypedEventEmitter<{
-		change: (id: string) => void;
+		change: (id: string, isDeleted: boolean) => void;
+		close: () => void;
 		event: (event: RollupWatcherEvent) => void;
 		restart: () => void;
 	}> {

src/utils/PluginContext.ts

@@ -126,6 +126,7 @@ export function getPluginContexts(
 			getFileName: fileEmitter.getFileName,
 			getModuleIds: () => graph.modulesById.keys(),
 			getModuleInfo: graph.getModuleInfo,
+			getWatchFiles: () => Object.keys(graph.watchFiles),
 			isExternal: getDeprecatedContextHandler(
 				(id: string, parentId: string | undefined, isResolved = false) =>
 					options.external(id, parentId, isResolved),

src/utils/PluginDriver.ts

@@ -47,6 +47,7 @@ const inputHookNames: {
 } = {
 	buildEnd: 1,
 	buildStart: 1,
+	closeWatcher: 1,
 	load: 1,
 	moduleParsed: 1,
 	options: 1,

src/watch/fileWatcher.ts

@@ -45,7 +45,7 @@ export class FileWatcher {
 		const task = this.task;
 		const isLinux = platform() === 'linux';
 		const isTransformDependency = transformWatcherId !== null;
-		const handleChange = (id: string) => {
+		const handleChange = (id: string, _: unknown, isDeleted = false) => {
 			const changedId = transformWatcherId || id;
 			if (isLinux) {
 				// unwatching and watching fixes an issue with chokidar where on certain systems,
@@ -54,13 +54,13 @@ export class FileWatcher {
 				watcher.unwatch(changedId);
 				watcher.add(changedId);
 			}
-			task.invalidate(changedId, isTransformDependency);
+			task.invalidate(changedId, isTransformDependency, isDeleted);
 		};
 		const watcher = chokidar
 			.watch([], this.chokidarOptions)
 			.on('add', handleChange)
 			.on('change', handleChange)
-			.on('unlink', handleChange);
+			.on('unlink', id => handleChange(id, null, true));
 		return watcher;
 	}
 }

src/watch/fsevents-importer.ts

@@ -2,6 +2,7 @@ let fsEvents: any;
 let fsEventsImportError: any;
 
 export function loadFsEvents() {
+	// @ts-ignore
 	return import('fsevents')
 		.then(namespace => {
 			fsEvents = namespace.default;

src/watch/watch.ts

@@ -18,6 +18,7 @@ export class Watcher {
 
 	private buildDelay = 0;
 	private buildTimeout: NodeJS.Timer | null = null;
+	private deletedIds: Set<string> = new Set();
 	private invalidatedIds: Set<string> = new Set();
 	private rerun = false;
 	private running: boolean;
@@ -43,16 +44,21 @@ export class Watcher {
 		for (const task of this.tasks) {
 			task.close();
 		}
+		this.emit('close')
 		this.emitter.removeAllListeners();
 	}
 
-	emit(event: string, value?: any) {
-		this.emitter.emit(event as any, value);
+	emit(event: string, ...args: unknown[]) {
+		this.emitter.emit(event as any, ...args);
 	}
 
-	invalidate(id?: string) {
+	invalidate(id?: string, isDeleted?: boolean) {
 		if (id) {
 			this.invalidatedIds.add(id);
+			if (isDeleted)
+				this.deletedIds.add(id);
+			else
+				this.deletedIds.delete(id)
 		}
 		if (this.running) {
 			this.rerun = true;
@@ -64,9 +70,10 @@ export class Watcher {
 		this.buildTimeout = setTimeout(() => {
 			this.buildTimeout = null;
 			for (const id of this.invalidatedIds) {
-				this.emit('change', id);
+				this.emit('change', id, this.deletedIds.has(id));
 			}
 			this.invalidatedIds.clear();
+			this.deletedIds.clear();
 			this.emit('restart');
 			this.run();
 		}, this.buildDelay);
@@ -144,7 +151,7 @@ export class Task {
 		this.fileWatcher.close();
 	}
 
-	invalidate(id: string, isTransformDependency: boolean | undefined) {
+	invalidate(id: string, isTransformDependency: boolean | undefined, isDeleted: boolean) {
 		this.invalidated = true;
 		if (isTransformDependency) {
 			for (const module of this.cache.modules) {
@@ -153,7 +160,7 @@ export class Task {
 				module.originalCode = null as any;
 			}
 		}
-		this.watcher.invalidate(id);
+		this.watcher.invalidate(id, isDeleted);
 	}
 
 	async run() {

test/watch/index.js

@@ -237,6 +237,134 @@ describe('rollup.watch', () => {
 			});
 	});
 
+	it('passes isDeleted parameter to the watchChange plugin hook', () => {
+		const deleted = [];
+		let ids;
+		const expectedIds = ['test/_tmp/input/watched', path.resolve('test/_tmp/input/main.js')];
+		return sander
+			.copydir('test/watch/samples/watch-files')
+			.to('test/_tmp/input')
+			.then(() => {
+				watcher = rollup.watch({
+					input: 'test/_tmp/input/main.js',
+					output: {
+						file: 'test/_tmp/output/bundle.js',
+						format: 'cjs',
+						exports: 'auto'
+					},
+					plugins: {
+						buildStart() {
+							this.addWatchFile('test/_tmp/input/watched');
+						},
+						watchChange(id, isDeleted) {
+							assert.strictEqual(id, 'test/_tmp/input/watched');
+							deleted.push(isDeleted);
+						},
+						buildEnd() {
+							ids = this.getWatchFiles();
+						}
+					}
+				});
+
+				return sequence(watcher, [
+					'START',
+					'BUNDLE_START',
+					'BUNDLE_END',
+					'END',
+					() => {
+						assert.strictEqual(run('../_tmp/output/bundle.js'), 42);
+						assert.deepStrictEqual(deleted, []);
+						assert.deepStrictEqual(ids, expectedIds);
+						sander.writeFileSync('test/_tmp/input/watched', 'another');
+					},
+					'START',
+					'BUNDLE_START',
+					'BUNDLE_END',
+					'END',
+					() => {
+						assert.strictEqual(run('../_tmp/output/bundle.js'), 42);
+						assert.deepStrictEqual(deleted, [false]);
+						assert.deepStrictEqual(ids, expectedIds);
+						sander.rimrafSync('test/_tmp/input/watched');
+					},
+					'START',
+					'BUNDLE_START',
+					'BUNDLE_END',
+					'END',
+					() => {
+						assert.strictEqual(run('../_tmp/output/bundle.js'), 42);
+						assert.deepStrictEqual(deleted, [false, true]);
+						assert.deepStrictEqual(ids, expectedIds);
+						sander.writeFileSync('test/_tmp/input/watched', 'third');
+					},
+					'START',
+					'BUNDLE_START',
+					'BUNDLE_END',
+					'END',
+					() => {
+						assert.strictEqual(run('../_tmp/output/bundle.js'), 42);
+						assert.deepStrictEqual(deleted, [false, true, false]);
+						assert.deepStrictEqual(ids, expectedIds);
+					}
+				]);
+			});
+	});
+
+	it('calls closeWatcher plugin hook', () => {
+		let calls = 0;
+		let ctx1;
+		let ctx2;
+		return sander
+			.copydir('test/watch/samples/basic')
+			.to('test/_tmp/input')
+			.then(() => {
+				watcher = rollup.watch({
+					input: 'test/_tmp/input/main.js',
+					output: {
+						file: 'test/_tmp/output/bundle.js',
+						format: 'cjs',
+						exports: 'auto'
+					},
+					plugins: [
+						{
+							buildStart() {
+								ctx1 = this;
+							},
+							closeWatcher() {
+								assert.strictEqual(ctx1, this);
+								calls++;
+							}
+						},
+						{
+							buildStart() {
+								ctx2 = this;
+							},
+							closeWatcher() {
+								assert.strictEqual(ctx2, this);
+								calls++;
+							}
+						},
+					]
+				});
+
+				return sequence(watcher, [
+					'START',
+					'BUNDLE_START',
+					'BUNDLE_END',
+					'END',
+					() => {
+						assert.strictEqual(run('../_tmp/output/bundle.js'), 42);
+						assert.ok(ctx1);
+						assert.ok(ctx2);
+						watcher.once('close', () => {
+							assert.strictEqual(calls, 2);
+						});
+						watcher.close();
+					},
+				]);
+			});
+	});
+
 	it('watches a file in code-splitting mode', () => {
 		return sander
 			.copydir('test/watch/samples/code-splitting')