React Hook Form does not upadate `errors` field on parent when triggering children

When you type in solution.latex:

1. RHF calls your resolver with names = ['solution.latex'].

2. zodResolver(schema) runs validation for the whole schema (including your solution.refine(...)).

3. Your refine on solution correctly returns a Zod issue whose path is something like:

   path: [''] // relative to the "solution" object
   
   

4. After validation, zodResolver filters the issues down to just the field(s) being validated.
   Since this run was for solution.latex, it only keeps issues whose path maps to solution.latex (or deeper), and it drops the parent-level solution issue.

5. Result: errors.solution doesn’t change when only solution.latex is being validated.

This behavior is intentional: RHF focuses on field-level validation. The maintainer explicitly says that for dependent / cross-field validation you need to use trigger to revalidate the relevant fields.

Your workaround:

if (name?.startsWith('solution')) {
  trigger('solution');
  trigger(name as FieldPath<HomeworkSchemaType>);
}

is basically doing exactly what the maintainer recommends:

“React hook form focus on field level validation, if you need dependent update use trigger api.”

So it’s not a hack, it’s the pattern.

So how do you do this cleanly?

You have a few options. All of them boil down to “when child fields change, also validate the parent”.

1. Use useWatch + trigger for solution

This is the same logic as your subscribe, but a bit more idiomatic:

const { control, trigger } = useForm<HomeworkSchemaType>({
  resolver: zodResolver(schema),
  mode: 'all',
});

const solutionValue = useWatch({
  control,
  name: 'solution',
});

useEffect(() => {
  // Whenever any solution.* field changes, revalidate the whole solution object
  void trigger('solution');
}, [solutionValue, trigger]);

Now your Zod refine on solution will run and its error will actually be attached to solution (because this time RHF asked to validate the solution field itself).

Your schema can stay essentially as-is (I’d just drop the path: [''], see below):

const schema = useMemo(
  () =>
    saveHomeworkSchema.extend({
      solution: solution
        .refine(
          (solution) =>
            latexSchema.safeParse(solution?.latex).success ||
            imagesSchema.safeParse(solution?.images).success ||
            videoSchema.safeParse(solution?.video).success ||
            solutionSteps.min(1).safeParse(solution?.steps).success,
          {
            // Let Zod use the default path => attaches to "solution"
            message: 'Musisz podać przynajmniej jeden format rozwiązania.',
          }
        )
        .refine(
          (solution) =>
            !solution?.video?.uploading ||
            solution?.images?.some((el) => el.uploading),
          {
            message: 'Trwa przesyłanie pliku...',
          }
        ),
    }),
  []
);

Zod will produce issues for solution itself, and trigger('solution') will let RHF keep those.

2. Trigger in field onChange

If you want more fine-grained control, you can trigger in the child fields themselves:

<Controller
  control={control}
  name="solution.latex"
  render={({ field }) => (
    <MyLatexEditor
      value={field.value}
      onChange={(value) => {
        field.onChange(value);
        void trigger('solution'); // revalidate combined rule
      }}
    />
  )}
/>

You’d do the same for solution.images, solution.video, etc.

Why mode: 'all' doesn’t help

mode: 'all' only controls when validation happens (onChange, onBlur, onSubmit).
It does not change what RHF asks the resolver to validate.

Even with mode: 'all', when you type in solution.latex, RHF still calls the resolver as if it’s validating only 'solution.latex', and it still filters out the solution-level issues.