feat: update amounts/percentages split logic to match OD (rework)

src/components/MoneyRequestAmountInput.tsx

@@ -96,6 +96,9 @@ type MoneyRequestAmountInputProps = {
     /** Whether to allow flipping amount */
     allowFlippingAmount?: boolean;
 
+    /** Whether to allow direct negative input (for split amounts where value is already negative) */
+    allowNegativeInput?: boolean;
+
     /** The testID of the input. Used to locate this view in end-to-end tests. */
     testID?: string;
 
@@ -162,6 +165,7 @@ function MoneyRequestAmountInput({
     shouldWrapInputInContainer = true,
     isNegative = false,
     allowFlippingAmount = false,
+    allowNegativeInput = false,
     toggleNegative,
     clearNegative,
     ref,
@@ -257,6 +261,7 @@ function MoneyRequestAmountInput({
             autoGrowExtraSpace={autoGrowExtraSpace}
             submitBehavior={submitBehavior}
             allowFlippingAmount={allowFlippingAmount}
+            allowNegativeInput={allowNegativeInput}
             toggleNegative={toggleNegative}
             clearNegative={clearNegative}
             onFocus={props.onFocus}

src/components/NumberWithSymbolForm.tsx

@@ -79,6 +79,9 @@ type NumberWithSymbolFormProps = {
     /** Whether to allow flipping amount */
     allowFlippingAmount?: boolean;
 
+    /** Whether to allow direct negative input (for split amounts where value is already negative) */
+    allowNegativeInput?: boolean;
+
     /** Whether the input is disabled or not */
     disabled?: boolean;
 
@@ -144,6 +147,7 @@ function NumberWithSymbolForm({
     shouldWrapInputInContainer = true,
     isNegative = false,
     allowFlippingAmount = false,
+    allowNegativeInput = false,
     toggleNegative,
     clearNegative,
     ref,
@@ -218,11 +222,13 @@ function NumberWithSymbolForm({
             const newNumberWithoutSpaces = stripSpacesFromAmount(newNumber);
             const rawFinalNumber = newNumberWithoutSpaces.includes('.') ? stripCommaFromAmount(newNumberWithoutSpaces) : replaceCommasWithPeriod(newNumberWithoutSpaces);
 
-            const finalNumber = handleNegativeAmountFlipping(rawFinalNumber, allowFlippingAmount, toggleNegative);
+            // When allowNegativeInput is true, keep negative sign as-is (for split amounts)
+            // When allowFlippingAmount is true, strip the negative sign and call toggleNegative
+            const finalNumber = allowNegativeInput ? rawFinalNumber : handleNegativeAmountFlipping(rawFinalNumber, allowFlippingAmount, toggleNegative);
 
             // Use a shallow copy of selection to trigger setSelection
             // More info: https://github.com/Expensify/App/issues/16385
-            if (!validateAmount(finalNumber, decimals, maxLength)) {
+            if (!validateAmount(finalNumber, decimals, maxLength, allowNegativeInput)) {
                 setSelection((prevSelection) => ({...prevSelection}));
                 return;
             }
@@ -242,7 +248,7 @@ function NumberWithSymbolForm({
             });
             onInputChange?.(strippedNumber);
         },
-        [decimals, maxLength, onInputChange, allowFlippingAmount, toggleNegative],
+        [decimals, maxLength, onInputChange, allowFlippingAmount, toggleNegative, allowNegativeInput],
     );
 
     /**
@@ -253,11 +259,14 @@ function NumberWithSymbolForm({
         // Remove spaces from the new number because Safari on iOS adds spaces when pasting a copied number
         // More info: https://github.com/Expensify/App/issues/16974
         const newNumberWithoutSpaces = stripSpacesFromAmount(text);
-        const replacedCommasNumber = handleNegativeAmountFlipping(replaceCommasWithPeriod(newNumberWithoutSpaces), allowFlippingAmount, toggleNegative);
+        // When allowNegativeInput is true, keep negative sign as-is
+        const replacedCommasNumber = allowNegativeInput
+            ? replaceCommasWithPeriod(newNumberWithoutSpaces)
+            : handleNegativeAmountFlipping(replaceCommasWithPeriod(newNumberWithoutSpaces), allowFlippingAmount, toggleNegative);
 
-        const withLeadingZero = addLeadingZero(replacedCommasNumber);
+        const withLeadingZero = addLeadingZero(replacedCommasNumber, allowNegativeInput);
 
-        if (!validateAmount(withLeadingZero, decimals, maxLength)) {
+        if (!validateAmount(withLeadingZero, decimals, maxLength, allowNegativeInput)) {
             setSelection((prevSelection) => ({...prevSelection}));
             return;
         }
@@ -280,7 +289,7 @@ function NumberWithSymbolForm({
     // Modifies the number to match changed decimals.
     useEffect(() => {
         // If the number supports decimals, we can return
-        if (validateAmount(currentNumber, decimals, maxLength, allowFlippingAmount)) {
+        if (validateAmount(currentNumber, decimals, maxLength, allowNegativeInput || allowFlippingAmount)) {
             return;
         }
 
@@ -305,14 +314,14 @@ function NumberWithSymbolForm({
                 if (currentNumber.length > 0) {
                     const selectionStart = selection.start === selection.end ? selection.start - 1 : selection.start;
                     const newNumber = `${currentNumber.substring(0, selectionStart)}${currentNumber.substring(selection.end)}`;
-                    setNewNumber(addLeadingZero(newNumber));
+                    setNewNumber(addLeadingZero(newNumber, allowNegativeInput));
                 }
                 return;
             }
-            const newNumber = addLeadingZero(`${currentNumber.substring(0, selection.start)}${key}${currentNumber.substring(selection.end)}`);
+            const newNumber = addLeadingZero(`${currentNumber.substring(0, selection.start)}${key}${currentNumber.substring(selection.end)}`, allowNegativeInput);
             setNewNumber(newNumber);
         },
-        [currentNumber, selection.start, selection.end, shouldUpdateSelection, setNewNumber],
+        [currentNumber, selection.start, selection.end, shouldUpdateSelection, setNewNumber, allowNegativeInput],
     );
 
     /**

src/components/SelectionList/ListItem/SplitListItem.tsx

@@ -43,7 +43,17 @@ function SplitListItem<TItem extends ListItem>({
 
     const formattedOriginalAmount = convertToDisplayStringWithoutCurrency(splitItem.originalAmount, splitItem.currency);
 
-    const onSplitExpenseValueChange = useCallback((value: string) => splitItem.onSplitExpenseValueChange(splitItem.transactionID, Number(value), splitItem.mode), [splitItem]);
+    const onSplitExpenseValueChange = useCallback(
+        (value: string) => {
+            const numericValue = Number(value);
+            // Skip update if value is just "-" or produces NaN (intermediate input state)
+            if (Number.isNaN(numericValue)) {
+                return;
+            }
+            splitItem.onSplitExpenseValueChange(splitItem.transactionID, numericValue, splitItem.mode);
+        },
+        [splitItem],
+    );
 
     const inputRef = useRef<BaseTextInputRef | null>(null);
 

src/components/SelectionList/ListItem/SplitListItem/SplitAmountInput.tsx

@@ -54,6 +54,7 @@ function SplitAmountInput({splitItem, formattedOriginalAmount, contentWidth, onS
                 shouldWrapInputInContainer={false}
                 onFocus={focusHandler}
                 onBlur={onInputBlur}
+                allowNegativeInput
             />
         );
     }