Promise error in IE11

[davidspiess]

Current Behavior

When calling setFieldValue with shouldValidate equals true, i get a Promise is undefined error in in IE11 (Formik 1.1.1).
This wasn't the case in 0.11.11.
Same happens when calling submitForm().

---

• Formik Version: 1.1.1
• React Version: 16.4.13
• TypeScript Version: 3.0.3
• Browser and Version: IE 11
• OS: Windows 10
• Node Version: 8.11.4
• Package Manager and Version: 6.4.0

[mvestergaard]

Not related to formik. IE11 does not have native support for promises. You need to polyfill them.

[davidspiess]

Maybe add a notice about that in the README.
It worked without polyfills before, so upgrading could cause IE 11 errors for a lot of users, without them noticing.

[prichodko]

It is usually handled during build process (using babel-preset-env for example), otherwise you have to polyfill it manually.