Error validation not working with Formik and Yup

Environment

Tech	Version
material-ui-pickers	2.2.1
material-ui	3.9.2
React	16.8.1
Browser	Chrome 71
Peer library	date-fns(date-io): 1.1.0
Formik	1.5.0
Yup	0.26.10

Steps to reproduce

1. A form using formik with an InlineDatePicker and formik configured for Yup schema validation.
2. The shema of validation validates some stuffs on the fields of InlineDatePicker. Here as schema definition for those files:

startDate: Yup.date().required(),
  endDate: Yup.date().when('startDate', (startDate, schema) => (startDate ? schema.min(startDate) : schema.date())),

1. There is no errors at all that appears. If I remove those two schema validation, it works perfectly.

Expected behavior

The picker does not block schema validation.

Actual behavior

Schema validation is no more working for any field on the schema.

[maxmann74]

I am having this issue as well. The “Invalid Date” error shows up, but when I clear the value, the “Required” error never shows up.

[nilamsavani91]

I’m also trying to figure out how to use yup with the date-picker.

I also want to set the validation if the endDate is less than StartDate. I am using KeyboardDatePicker from material-ui pickers.