fix: checkbox logic (#1537)

## Description

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## Related Issue

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## Changes Made

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- Change 1
- Change 2
- ...

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## Checklist

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- [ ] I have tested these changes locally and they work as expected.
- [ ] I have added/updated tests that prove the effectiveness of these
changes.
- [ ] I have updated the documentation to reflect these changes, if
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## Additional Notes

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apps/web/src/app/(signing)/sign/[token]/checkbox-field.tsx

@@ -12,6 +12,7 @@ import { DO_NOT_INVALIDATE_QUERY_ON_MUTATION } from '@documenso/lib/constants/tr
 import { AppError, AppErrorCode } from '@documenso/lib/errors/app-error';
 import type { TRecipientActionAuth } from '@documenso/lib/types/document-auth';
 import { ZCheckboxFieldMeta } from '@documenso/lib/types/field-meta';
+import { fromCheckboxValue, toCheckboxValue } from '@documenso/lib/universal/field-checkbox';
 import type { Recipient } from '@documenso/prisma/client';
 import type { FieldWithSignatureAndFieldMeta } from '@documenso/prisma/types/field-with-signature-and-fieldmeta';
 import { trpc } from '@documenso/trpc/react';
@@ -54,6 +55,7 @@ export const CheckboxField = ({
     ...item,
     value: item.value.length > 0 ? item.value : `empty-value-${item.id}`,
   }));
+
   const [checkedValues, setCheckedValues] = useState(
     values
       ?.map((item) =>
@@ -97,7 +99,7 @@ export const CheckboxField = ({
       const payload: TSignFieldWithTokenMutationSchema = {
         token: recipient.token,
         fieldId: field.id,
-        value: checkedValues.join(','),
+        value: toCheckboxValue(checkedValues),
         isBase64: true,
         authOptions,
       };
@@ -191,7 +193,7 @@ export const CheckboxField = ({
           await signFieldWithToken({
             token: recipient.token,
             fieldId: field.id,
-            value: updatedValues.join(','),
+            value: toCheckboxValue(checkedValues),
             isBase64: true,
           });
         }
@@ -228,6 +230,11 @@ export const CheckboxField = ({
     }
   }, [checkedValues, isLengthConditionMet, field.inserted]);
 
+  const parsedCheckedValues = useMemo(
+    () => fromCheckboxValue(field.customText),
+    [field.customText],
+  );
+
   return (
     <SigningFieldContainer field={field} onSign={onSign} onRemove={onRemove} type="Checkbox">
       {isLoading && (
@@ -277,9 +284,7 @@ export const CheckboxField = ({
                   className="h-3 w-3"
                   checkClassName="text-white"
                   id={`checkbox-${index}`}
-                  checked={field.customText
-                    .split(',')
-                    .some((customValue) => customValue === itemValue)}
+                  checked={parsedCheckedValues.includes(itemValue)}
                   disabled={isLoading}
                   onCheckedChange={() => void handleCheckboxOptionClick(item)}
                 />

packages/lib/server-only/field/sign-field-with-token.ts

@@ -8,6 +8,7 @@ import { validateDropdownField } from '@documenso/lib/advanced-fields-validation
 import { validateNumberField } from '@documenso/lib/advanced-fields-validation/validate-number';
 import { validateRadioField } from '@documenso/lib/advanced-fields-validation/validate-radio';
 import { validateTextField } from '@documenso/lib/advanced-fields-validation/validate-text';
+import { fromCheckboxValue } from '@documenso/lib/universal/field-checkbox';
 import { prisma } from '@documenso/prisma';
 import { DocumentStatus, FieldType, SigningStatus } from '@documenso/prisma/client';
 
@@ -119,7 +120,8 @@ export const signFieldWithToken = async ({
 
   if (field.type === FieldType.CHECKBOX && field.fieldMeta) {
     const checkboxFieldParsedMeta = ZCheckboxFieldMeta.parse(field.fieldMeta);
-    const checkboxFieldValues = value.split(',');
+    const checkboxFieldValues: string[] = fromCheckboxValue(value);
+
     const errors = validateCheckboxField(checkboxFieldValues, checkboxFieldParsedMeta, true);
 
     if (errors.length > 0) {

packages/lib/server-only/pdf/insert-field-in-pdf.ts

@@ -10,6 +10,7 @@ import {
   MIN_HANDWRITING_FONT_SIZE,
   MIN_STANDARD_FONT_SIZE,
 } from '@documenso/lib/constants/pdf';
+import { fromCheckboxValue } from '@documenso/lib/universal/field-checkbox';
 import { FieldType } from '@documenso/prisma/client';
 import { isSignatureFieldType } from '@documenso/prisma/guards/is-signature-field';
 import type { FieldWithSignature } from '@documenso/prisma/types/field-with-signature';
@@ -194,7 +195,7 @@ export const insertFieldInPDF = async (pdf: PDFDocument, field: FieldWithSignatu
         value: item.value.length > 0 ? item.value : `empty-value-${item.id}`,
       }));
 
-      const selected = field.customText.split(',');
+      const selected: string[] = fromCheckboxValue(field.customText);
 
       for (const [index, item] of (values ?? []).entries()) {
         const offsetY = index * 16;

packages/lib/universal/field-checkbox.ts

@@ -0,0 +1,21 @@
+export const fromCheckboxValue = (customText: string): string[] => {
+  if (!customText) {
+    return [];
+  }
+
+  try {
+    const parsed = JSON.parse(customText);
+
+    if (!Array.isArray(parsed)) {
+      throw new Error('Parsed checkbox values are not an array');
+    }
+
+    return parsed;
+  } catch {
+    return customText.split(',').filter(Boolean);
+  }
+};
+
+export const toCheckboxValue = (values: string[]): string => {
+  return JSON.stringify(values);
+};