Synchronous validation

Bug, Feature, or Question?

Question

Current Behavior

Since Yup validations are async, components render twice as far as I’ve read in previous issues, and I have 150 input fields on one page and it’s extremely noticeable when user starts to type, it basically becomes unusable. So, since there is boolean flag in validateYupSchema method for synchronous version is there a way to set it as prop on Formik component?

Desired Behavior

To run Yup validations synchronously.

---

• Formik Version: 1.0.0-alpha.2
• React Version: 16.2.0
• OS: MacOS
• Node Version: 8.9.1
• Package Manager and Version: npm v5.6.0

[latviancoder]

By the way, this is how I did synchronous validation using yup and validate function:

import { validateYupSchema, yupToFormErrors } from 'formik';

validate: (values: FormValues) => {
    const validationSchema = object().shape({
        ...
    });

    try {
        validateYupSchema<FormValues>(values, validationSchema, true);
    } catch (err) {
        return yupToFormErrors(err);
    }

    return {};
},

[pietmichal]

This is even more relevant now because async validation now triggers act errors in tests when using React Hooks.