don't search for nothing, fixes #26423

src/vs/base/common/filters.ts

@@ -478,6 +478,9 @@ export function fuzzyScore(pattern: string, word: string): [number, number[]] {
 		return undefined;
 	}
 
+	// keep track of the maximum score
+	let maxScore = -1;
+
 	for (i = 1; i <= patternLen; i++) {
 
 		let lastLowWordChar = '';
@@ -509,6 +512,9 @@ export function fuzzyScore(pattern: string, word: string): [number, number[]] {
 			}
 
 			_scores[i][j] = score;
+			if (score > maxScore) {
+				maxScore = score;
+			}
 
 			let diag = _table[i - 1][j - 1] + (score > 1 ? 1 : score);
 			let top = _table[i - 1][j] + -1;
@@ -544,6 +550,10 @@ export function fuzzyScore(pattern: string, word: string): [number, number[]] {
 		}
 	}
 
+	if (maxScore <= 1) {
+		return undefined;
+	}
+
 	if (_debug) {
 		console.log(printTable(_table, pattern, patternLen, word, wordLen));
 		console.log(printTable(_arrows, pattern, patternLen, word, wordLen));

src/vs/base/test/common/filters.test.ts

@@ -305,6 +305,21 @@ suite('Filters', () => {
 		);
 	});
 
+	test('fuzzyScore, issue #26423', function () {
+		assertMatches(
+			'fsfsfs',
+			'dsafdsafdsafdsafdsafdsafdsafasdfdsa',
+			undefined,
+			fuzzyScore
+		);
+		assertMatches(
+			'fsfsfsfsfsfsfsf',
+			'dsafdsafdsafdsafdsafdsafdsafasdfdsafdsafdsafdsafdsfdsafdsfdfdfasdnfdsajfndsjnafjndsajlknfdsa',
+			undefined,
+			fuzzyScore
+		);
+	});
+
 	function assertTopScore(filter: typeof fuzzyScore, pattern: string, expected: number, ...words: string[]) {
 		let topScore = -(100 * 10);
 		let topIdx = 0;