Styles
First, indicate the directory to resolve style modules from:
src/index.js
roots.register.styles('./')
Then, create *.style.{js,ts}
modules.
Each should export the required properties of the WordPress block styles API.
Example​
Using named exports:
src/example.style.js
export const block = `core/list`
export const name = `custom`
export const label = `Custom`
export const isDefault = false
Using a default export:
src/example.style.js
export default {
block: `core/list`,
name: `custom`,
label: `Custom`,
isDefault: false,
}