Watcher: allow to fully turn off a watcher for a workspace via files.watcherExclude (microsoft#150951)

Author: bpasero

src/vs/platform/files/node/watcher/parcel/parcelWatcher.ts

@@ -11,7 +11,7 @@ import { CancellationToken, CancellationTokenSource } from 'vs/base/common/cance
 import { toErrorMessage } from 'vs/base/common/errorMessage';
 import { Emitter } from 'vs/base/common/event';
 import { isEqualOrParent, randomPath } from 'vs/base/common/extpath';
-import { ParsedPattern, patternsEquals } from 'vs/base/common/glob';
+import { GLOBSTAR, ParsedPattern, patternsEquals } from 'vs/base/common/glob';
 import { Disposable } from 'vs/base/common/lifecycle';
 import { TernarySearchTree } from 'vs/base/common/map';
 import { normalizeNFC } from 'vs/base/common/normalization';
@@ -663,12 +663,17 @@ export class ParcelWatcher extends Disposable implements IRecursiveWatcher {
 
 		// Only consider requests for watching that are not
 		// a child of an existing request path to prevent
-		// duplication.
+		// duplication. In addition, drop any request where
+		// everything is excluded (via `**` glob).
 		//
 		// However, allow explicit requests to watch folders
 		// that are symbolic links because the Parcel watcher
 		// does not allow to recursively watch symbolic links.
 		for (const request of requests) {
+			if (request.excludes.includes(GLOBSTAR)) {
+				continue; // path is ignored entirely (via `**` glob exclude)
+			}
+
 			if (requestTrie.findSubstr(request.path)) {
 				try {
 					const realpath = realpathSync(request.path);

src/vs/platform/files/test/node/parcelWatcher.integrationTest.ts

@@ -26,11 +26,11 @@ import { ltrim } from 'vs/base/common/strings';
 
 	class TestParcelWatcher extends ParcelWatcher {
 
-		testNormalizePaths(paths: string[]): string[] {
+		testNormalizePaths(paths: string[], excludes: string[] = []): string[] {
 
 			// Work with strings as paths to simplify testing
 			const requests: IRecursiveWatchRequest[] = paths.map(path => {
-				return { path, excludes: [], recursive: true };
+				return { path, excludes, recursive: true };
 			});
 
 			return this.normalizeRequests(requests).map(request => request.path);
@@ -555,6 +555,10 @@ import { ltrim } from 'vs/base/common/strings';
 		}
 	});
 
+	test('should ignore when everything excluded', () => {
+		assert.deepStrictEqual(watcher.testNormalizePaths(['/foo/bar', '/bar'], ['**', 'something']), []);
+	});
+
 	test('excludes are converted to absolute paths', () => {
 
 		// undefined / empty