addons/viewport/src/constants.ts
export const ADDON_ID = 'storybook/viewport';
export const PARAM_KEY = 'viewport';
export const UPDATE = `${ADDON_ID}/update`;
export const CONFIGURE = `${ADDON_ID}/configure`;
export const SET = `${ADDON_ID}/setStoryDefaultViewport`;
export const CHANGED = `${ADDON_ID}/viewportChanged`;