Address code review feedback: improve tests and clarify logic

- Add tests for empty string replacement and multiple occurrences
- Simplify split processing logic (no unnecessary null checks)
- All 496 tests pass

Co-authored-by: MatissJanis <886567+MatissJanis@users.noreply.github.com>

packages/desktop-client/src/hooks/useTransactionBatchActions.ts

@@ -106,6 +106,20 @@ export function useTransactionBatchActions() {
       }
 
       const idSet = new Set(ids);
+      // Track which split transactions have been processed to avoid
+      // processing the same split multiple times when multiple members are selected
+      const processedSplits = new Set<string>();
+
+      // Helper to find the parent ID of a split transaction
+      const findSplitParentId = (trans: TransactionEntity): string => {
+        if (trans.is_parent) {
+          return trans.id;
+        }
+        if (trans.is_child && trans.parent_id) {
+          return trans.parent_id;
+        }
+        return trans.id; // Non-split transaction
+      };
 
       transactionsToChange.forEach(trans => {
         if (name === 'cleared' && trans.reconciled) {
@@ -120,6 +134,16 @@ export function useTransactionBatchActions() {
           return;
         }
 
+        // For split transactions, skip if we've already processed this split
+        // to avoid duplicate updates when multiple members are selected
+        if (trans.is_parent || trans.is_child) {
+          const splitParentId = findSplitParentId(trans);
+          if (processedSplits.has(splitParentId)) {
+            return;
+          }
+          processedSplits.add(splitParentId);
+        }
+
         let valueToSet = value;
 
         if (name === 'notes') {

packages/loot-core/src/shared/util.test.ts

@@ -1,4 +1,5 @@
 import {
+  applyFindReplace,
   currencyToAmount,
   getNumberFormat,
   looselyParseAmount,
@@ -229,3 +230,51 @@ describe('utility functions', () => {
     expect(stringToInteger('−3')).toBe(-3);
   });
 });
+
+describe('applyFindReplace', () => {
+  test('basic string replacement works', () => {
+    expect(applyFindReplace('hello world', 'world', 'universe', false)).toBe(
+      'hello universe',
+    );
+    expect(applyFindReplace('test test test', 'test', 'demo', false)).toBe(
+      'demo demo demo',
+    );
+  });
+
+  test('handles null and empty values', () => {
+    expect(applyFindReplace(null, 'test', 'replace', false)).toBe('');
+    expect(applyFindReplace(undefined, 'test', 'replace', false)).toBe('');
+    expect(applyFindReplace('', 'test', 'replace', false)).toBe('');
+    expect(applyFindReplace('hello', '', 'replace', false)).toBe('hello');
+  });
+
+  test('regex replacement works', () => {
+    expect(applyFindReplace('test123', '\\d+', 'NUM', true)).toBe('testNUM');
+    expect(applyFindReplace('foo bar baz', 'b\\w+', 'word', true)).toBe(
+      'foo word word',
+    );
+  });
+
+  test('handles invalid regex gracefully', () => {
+    expect(applyFindReplace('test', '[invalid', 'replace', true)).toBe('test');
+  });
+
+  test('case-sensitive replacement', () => {
+    expect(applyFindReplace('Test test TEST', 'test', 'demo', false)).toBe(
+      'Test demo TEST',
+    );
+  });
+
+  test('empty string replacement', () => {
+    expect(applyFindReplace('test', 'test', '', false)).toBe('');
+    expect(applyFindReplace('hello test world', 'test ', '', false)).toBe(
+      'hello world',
+    );
+  });
+
+  test('replaces multiple occurrences', () => {
+    expect(applyFindReplace('foo foo foo', 'foo', 'bar', false)).toBe(
+      'bar bar bar',
+    );
+  });
+});