Function calculateNextFormState

src/FinalForm.ts:595–701

()

    !!(state.formState.error || hasAnyError(state.formState.errors));

  const calculateNextFormState = (): FormState<FormValues, InitialFormValues> => {
    const { fields, formState, lastFormState } = state;
    const safeFields = { ...fields };
    const safeFieldKeys = Object.keys(safeFields);

    // calculate dirty/pristine
    let foundDirty = false;
    const dirtyFields = safeFieldKeys.reduce((result, key) => {
      const dirty = !safeFields[key].isEqual(
        getIn(formState.values as Record<string, any>, key),
        getIn(formState.initialValues as Record<string, any> || {}, key),
      );
      if (dirty) {
        foundDirty = true;
        result[key] = true;
      }
      return result;
    }, {});

    // FIX #487: For unregistered fields, check if their values differ from initialValues
    // This handles cases like FieldArray where the array itself isn't registered
    if (!foundDirty) {
      // Dedupe keys using Set to avoid duplicate checks
      const allKeys = new Set([
        ...Object.keys(formState.values || {}),
        ...Object.keys(formState.initialValues || {})
      ]);
      for (const key of allKeys) {
        if (!safeFields[key]) {
          const currentValue = (formState.values as any)?.[key];
          const initialValue = (formState.initialValues as any)?.[key];
          if (!shallowEqual(currentValue, initialValue)) {
            foundDirty = true;
            break;
          }
        }
      }
    }
    const dirtyFieldsSinceLastSubmit = safeFieldKeys.reduce((result, key) => {
      // istanbul ignore next
      const nonNullLastSubmittedValues = formState.lastSubmittedValues || {}; // || {} is for flow, but causes branch coverage complaint
      if (
        !safeFields[key].isEqual(
          getIn(formState.values as Record<string, any>, key),
          getIn(nonNullLastSubmittedValues, key),
        )
      ) {
        result[key] = true;
      }
      return result;
    }, {});
    formState.pristine = !foundDirty;
    formState.dirtySinceLastSubmit = !!(
      formState.lastSubmittedValues &&
      Object.values(dirtyFieldsSinceLastSubmit).some((value) => value)
    );
    formState.modifiedSinceLastSubmit = !!(
      formState.lastSubmittedValues &&