handleChange bug for empty number values: parseFloat('') is null

[cloud-walker]

Input type number will be cast to null when cleared, because of this:

formik/src/formik.tsx

Line 389 in 61a0869

? parseFloat(value)

Demo with the latest version of formik: https://codesandbox.io/s/m7268r7xoy

[jaredpalmer]

True true.

[jaredpalmer]

Should this be parseFloat(val) !== null ? parseFloat(val) : ''?

[drew-dulgar]

Related issue: #284

Also, for checking the value, what about this?

Number.isNaN(Number.parseFloat(val)) ? '' : Number.parseFloat(val);

[jaredpalmer]

Submit a PR and with this change and a test if you get a chance

[victordidenko]

Didn't make test though...