fix(filters): support project filter in parentheses (#1647)

The filter regex pattern was not matching values inside parentheses correctly.
The lookahead pattern only allowed `&&`, `||`, or end-of-string after filter
values, but when filters are wrapped in parentheses like `( project = Filtertest )`,
the closing `)` appears after the value.

Fixed by adding `\)` to the lookahead pattern so it correctly handles closing
parentheses. This allows the project filter (and other filters) to work
properly when nested in parentheses.

- Added tests for project filters in parentheses (both frontend and backend)
- Backend tests confirm the backend already handled this correctly
- Frontend regex pattern now matches the backend behavior

Fixes #1645

frontend/src/helpers/filters.test.ts

@@ -187,6 +187,26 @@ describe('Filter Transformation', () => {
 
 			expect(transformed).toBe('project = 1')
 		})
+
+		it('should correctly resolve project in parentheses', () => {
+			const transformed = transformFilterStringForApi(
+				'( project = Filtertest )',
+				nullTitleToIdResolver,
+				(title: string) => title === 'Filtertest' ? 123 : null,
+			)
+
+			expect(transformed).toBe('( project = 123 )')
+		})
+
+		it('should correctly resolve project with OR in parentheses', () => {
+			const transformed = transformFilterStringForApi(
+				'( labels = label || project = Filtertest )',
+				(title: string) => title === 'label' ? 456 : null,
+				(title: string) => title === 'Filtertest' ? 123 : null,
+			)
+
+			expect(transformed).toBe('( labels = 456 || project = 123 )')
+		})
 	})
 
 	describe('Special Characters', () => {

frontend/src/helpers/filters.ts

@@ -81,7 +81,7 @@ export function hasFilterQuery(filter: string): boolean {
 }
 
 export function getFilterFieldRegexPattern(field: string): RegExp {
-	return new RegExp('\\b(' + field + ')\\s*' + FILTER_OPERATORS_REGEX + '\\s*(?:(["\'])((?:\\\\.|(?!\\3)[^\\\\])*?)\\3|([^&|()<]+?))(?=\\s*(?:&&|\\||$))', 'g')
+	return new RegExp('\\b(' + field + ')\\s*' + FILTER_OPERATORS_REGEX + '\\s*(?:(["\'])((?:\\\\.|(?!\\3)[^\\\\])*?)\\3|([^&|()<]+?))(?=\\s*(?:&&|\\||\\)|$))', 'g')
 }
 
 export function transformFilterStringForApi(

pkg/models/task_collection_filter_test.go

@@ -284,4 +284,31 @@ func TestParseFilter(t *testing.T) {
 			assert.Equal(t, 0, date.Year())
 		}
 	})
+	t.Run("project with parentheses", func(t *testing.T) {
+		result, err := getTaskFiltersFromFilterString("( project = 1 )", "UTC")
+
+		require.NoError(t, err)
+		require.Len(t, result, 1)
+		require.Len(t, result[0].value, 1)
+
+		firstSet := result[0].value.([]*taskFilter)
+		assert.Equal(t, "project_id", firstSet[0].field)
+		assert.Equal(t, taskFilterComparatorEquals, firstSet[0].comparator)
+		assert.Equal(t, int64(1), firstSet[0].value)
+	})
+	t.Run("project with OR in parentheses", func(t *testing.T) {
+		result, err := getTaskFiltersFromFilterString("( done = false || project = 1 )", "UTC")
+
+		require.NoError(t, err)
+		require.Len(t, result, 1)
+		require.Len(t, result[0].value, 2)
+
+		firstSet := result[0].value.([]*taskFilter)
+		assert.Equal(t, "done", firstSet[0].field)
+		assert.Equal(t, taskFilterComparatorEquals, firstSet[0].comparator)
+		assert.Equal(t, false, firstSet[0].value)
+		assert.Equal(t, "project_id", firstSet[1].field)
+		assert.Equal(t, taskFilterComparatorEquals, firstSet[1].comparator)
+		assert.Equal(t, int64(1), firstSet[1].value)
+	})
 }