storybook: Storyshots does not render JSX in addDecorator

Describe the bug addDecorator from storybook/react does not appear to be called in storyshots, even though it’s called in Storybook itself.

[EDIT] This appears to be the case only in .jsx and .tsx files.

To Reproduce Minimal repro can be found at this repository: https://github.com/LeapYear/storybook-storyshots-repro

Expected behavior addDecorator should be called with storyshots

Possibly related issues https://github.com/storybookjs/storybook/issues/3246

• Appears superficially related, however, the migration instructions from 5.2 -> 5.3 instruct to move all require calls from config.js to main.js, leaving addDecorator in place. However, the documentation for @storybook/react still recommends using configure(require.context(..), ..). Is the documentation inconsistent?