fix: escape square brackets in field name regex pattern (#752)

Author: jorisre

src/__tests__/toNestErrors.ts

@@ -284,3 +284,24 @@ test('ensures consistent ordering when a field array has a root error and an err
     },
   });
 });
+
+test('should correctly validate object with special characters', () => {
+  const result = toNestErrors(
+    { '[array-2]': { type: 'string', message: 'string is required' } },
+    {
+      names: ['[array-2]'],
+      fields: {
+        '[array-2]': { name: '[array-2]', ref: { name: '[array-2]' } },
+      },
+      shouldUseNativeValidation: false,
+    },
+  );
+
+  expect(result).toEqual({
+    'array-2': {
+      type: 'string',
+      message: 'string is required',
+      ref: { name: '[array-2]' },
+    },
+  });
+});

src/toNestErrors.ts

@@ -38,4 +38,18 @@ export const toNestErrors = <TFieldValues extends FieldValues>(
 const isNameInFieldArray = (
   names: InternalFieldName[],
   name: InternalFieldName,
-) => names.some((n) => n.match(`^${name}\\.\\d+`));
+) => {
+  const path = escapeBrackets(name);
+  return names.some((n) => escapeBrackets(n).match(`^${path}\\.\\d+`));
+};
+
+/**
+ * Escapes special characters in a string to be used in a regex pattern.
+ * it removes the brackets from the string to match the `set` method.
+ *
+ * @param input - The input string to escape.
+ * @returns The escaped string.
+ */
+function escapeBrackets(input: string): string {
+  return input.replace(/\]|\[/g, '');
+}