Material-ui: [withStyles] [typescript] flexDirection column is not a valid type

[weslenng]

Expected Behavior 🤔

It was expected that the "column" value would be accepted in the flexDirection property in a styles object of the withStyles function. As in the MDN definitions.

Current Behavior 😯

The Typescript is currently returning:
Argument of type '{ root: { flexDirection: string; }; }' is not assignable to parameter of type 'Styles<Theme, {}, "root">'.

Steps to Reproduce 🕹

Reproduction.

| Tech | Version |
|--------------|---------|
| Material-UI | v4.1.1 |
| React | v16.8.6 |
| TypeScript | v3.5.2 |

[eps1lon]

This is a common pitfall caused by TypeScript's type-widening by default. See Using createStyles to defeat type widening for more information on how to prevent those issues.

[slykar]

I have the exact same issue when using makeStyles or createStyles.