2 files changed, 69 insertions, 0 deletions
diff --git a/src/lib/shared/filter-items.test.ts b/src/lib/shared/filter-items.test.ts
new file mode 100644
index 0000000..3477cd1
--- /dev/null
+++ b/src/lib/shared/filter-items.test.ts
@@ -0,0 +1,53 @@
+import { describe, it, expect } from 'vitest';
+import { filterByName } from './filter-items';
+
+const routines = [
+	{ id: 1, name: 'Cuisine/Repas' },
+	{ id: 2, name: 'Cuisine/Vaisselle' },
+	{ id: 3, name: 'Salle de bain/Douche' },
+	{ id: 4, name: 'Étirements' },
+	{ id: 5, name: 'Course' },
+];
+
+describe('filterByName', () => {
+	it('filters by a namespace query like "Cuisine/"', () => {
+		const res = filterByName(routines, 'Cuisine/');
+		expect(res.map((r) => r.name)).toEqual([
+			'Cuisine/Repas',
+			'Cuisine/Vaisselle',
+		]);
+	});
+
+	it('matches a substring anywhere in the name', () => {
+		const res = filterByName(routines, 'epas');
+		expect(res.map((r) => r.name)).toEqual(['Cuisine/Repas']);
+	});
+
+	it('is case-insensitive', () => {
+		expect(filterByName(routines, 'cUiSiNe/')).toHaveLength(2);
+	});
+
+	it('folds accents on both sides', () => {
+		expect(filterByName(routines, 'etirements').map((r) => r.name)).toEqual([
+			'Étirements',
+		]);
+		expect(filterByName(routines, 'Étirements')).toHaveLength(1);
+	});
+
+	it('returns everything for an empty or whitespace query, order preserved', () => {
+		expect(filterByName(routines, '')).toEqual(routines);
+		expect(filterByName(routines, '   ')).toEqual(routines);
+	});
+
+	it('returns nothing when no name matches', () => {
+		expect(filterByName(routines, 'garage')).toEqual([]);
+	});
+
+	it('has no result cap', () => {
+		const many = Array.from({ length: 40 }, (_, i) => ({
+			id: i,
+			name: `Cuisine/Tâche ${i}`,
+		}));
+		expect(filterByName(many, 'Cuisine/')).toHaveLength(40);
+	});
+});
diff --git a/src/lib/shared/filter-items.ts b/src/lib/shared/filter-items.ts
new file mode 100644
index 0000000..e7e103b
--- /dev/null
+++ b/src/lib/shared/filter-items.ts
@@ -0,0 +1,16 @@
+/** Lowercase and strip diacritics so "etirements" matches "Étirements". */
+function fold(value: string): string {
+	return value.normalize('NFD').replace(/\p{M}/gu, '').toLowerCase();
+}
+
+/** Filter `items` to those whose `name` contains `query` as a literal
+ * substring, case- and accent-insensitive. Order is preserved and no result
+ * cap applies. Empty/whitespace query returns everything. */
+export function filterByName<T extends { name: string }>(
+	items: T[],
+	query: string,
+): T[] {
+	const q = fold(query.trim());
+	if (q === '') return items;
+	return items.filter((item) => fold(item.name).includes(q));
+}