From dd1fce5c8ad466109ad2faba77e6bfb06524c828 Mon Sep 17 00:00:00 2001
From: Leon Sorokin <leeoniya@gmail.com>
Date: Tue, 8 Jul 2025 14:14:00 -0500
Subject: [PATCH] Search: Use case-insensitive substring matching in
 fuzzySearch fallback (#107661)

---
 packages/grafana-data/src/utils/fuzzySearch.test.ts | 8 ++++++++
 packages/grafana-data/src/utils/fuzzySearch.ts      | 6 +++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/packages/grafana-data/src/utils/fuzzySearch.test.ts b/packages/grafana-data/src/utils/fuzzySearch.test.ts
index 71d75b27558..b53c26e98aa 100644
--- a/packages/grafana-data/src/utils/fuzzySearch.test.ts
+++ b/packages/grafana-data/src/utils/fuzzySearch.test.ts
@@ -48,6 +48,14 @@ describe('fuzzySearch', () => {
     expect(result.map((idx) => haystack[idx])).toEqual(['A水']);
   });
 
+  it('should do case-insensitive substring match when needle contains non-ascii characters', () => {
+    const haystack = ['Über'];
+    const needle = 'ü';
+    const result = fuzzySearch(haystack, needle);
+
+    expect(result.map((idx) => haystack[idx])).toEqual(['Über']);
+  });
+
   it('should handle multiple non-latin characters', () => {
     const haystack = ['台灣省', '台中市', '台北市', '台南市', '南投縣', '高雄市', '台中第一高級中學'];
     const needle = '南';
diff --git a/packages/grafana-data/src/utils/fuzzySearch.ts b/packages/grafana-data/src/utils/fuzzySearch.ts
index 72d1540f7b9..09ca02b7bc8 100644
--- a/packages/grafana-data/src/utils/fuzzySearch.ts
+++ b/packages/grafana-data/src/utils/fuzzySearch.ts
@@ -1,5 +1,7 @@
 import uFuzzy from '@leeoniya/ufuzzy';
 
+import { escapeRegex } from '../text/string';
+
 // https://catonmat.net/my-favorite-regex :)
 const REGEXP_NON_ASCII = /[^ -~]/m;
 // https://www.asciitable.com/
@@ -36,11 +38,13 @@ export function fuzzySearch(haystack: string[], needle: string): number[] {
     needle.length > maxNeedleLength ||
     uf.split(needle).length > maxFuzzyTerms
   ) {
+    const needleRegex = new RegExp(escapeRegex(needle), 'i');
     const indices: number[] = [];
+
     for (let i = 0; i < haystack.length; i++) {
       let item = haystack[i];
 
-      if (item.includes(needle)) {
+      if (needleRegex.test(item)) {
         indices.push(i);
       }
     }