Component Story Format (CSF)

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Storybook’s Component Story Format (CSF) is the recommended way to write stories since Storybook 5.2. Read the announcement to learn more about how it came to be.

In CSF, stories and component metadata are defined as ES6 modules. Every Component story file consists of a required default export and one or more named exports.

CSF is supported in all frameworks except React Native, where you should use the storiesOf API instead.

Default export

The default export defines metadata about your component, including the component itself, its title (where it will show up in the navigation UI story hierarchy), decorators, and parameters. title should be unique, i.e. not re-used across files.

import MyComponent from './MyComponent';

export default {
  title: 'Path|To/MyComponent',
  component: MyComponent,
  decorators: [ ... ],
  parameters: { ... }
}

For more examples, see writing stories

Story exports

By default every named export in the file represents a story function.

Story functions can be annotated with a story object to define story-level decorators and parameters, and also to define the name of the story.

The name is useful if you want to use names with spaces, names that correspond to restricted keywords in Javascript, or names that collide with other variables in the file. If it’s not specified, the export name will be used instead.

export const simple = () => <MyComponent prop1={val1} />;
simple.story = {
name: 'default', // can't be used as a named export
decorators: [ ... ],
parameters: { ... }
};

Storybook Export vs Name Handling

Storybook handles named exports and story.name slightly differently. When should you use one vs. the other?

In general, you should use named exports. Storybook passes them through a storyNameFromExport function (#7901), which is implemented with lodash.startCase:

it('should format CSF exports with sensible defaults', () => {
const testCases = {
  name: 'Name',
  someName: 'Some Name',
  someNAME: 'Some NAME',
  some_custom_NAME: 'Some Custom NAME',
  someName1234: 'Some Name 1234',
  someName1_2_3_4: 'Some Name 1 2 3 4',
};
Object.entries(testCases).forEach(([key, val]) => {
  expect(storyNameFromExport(key)).toBe(val);
});
});

When you want to change the name of your story, just rename the CSF export. This will change the name of the story and also change the Story’s ID / URL.

You should use the story.name option in the following cases:

  1. Want the name to show up in the Storybook UI in a way that’s not possible with a named export, e.g. reserved keywords like “default”, special characters like emoji, spacing/capitalization other than what’s provided by storyNameFromExport
  2. Want to preserve the Story ID independently from changing how it’s displayed. Having stable Story ID’s is useful for integration with third party tools.

Non-story exports

In some cases, you may want to export a mixture of story and non-stories. For example., it can be useful to export data that’s used in your stories.

To make this possible, you can use optional includeStories and excludeStories configuration fields in the default export, which can be set to either an array of strings, or a regular expression.

Consider the following story file:

import React from 'react';
import MyComponent from './MyComponent';
import someData from './data.json';

export default {
  title: 'MyComponent',
  component: MyComponent,
  includeStories: ['simpleStory', 'complexStory']
}
export const simpleData = { foo: 1, bar: 'baz' };
export const complexData = { foo: 1, { bar: 'baz', baz: someData }};
export const simpleStory = () => <MyComponent data={simpleData} />;
export const complexStory = () => <MyComponent data={complexData} />;

When Storybook loads this file, it will see all the exports, but it will ignore the data exports and only treat simpleStory and complexStory as stories.

For this specific example the equivalent result can be achieved in a few ways depending on what’s convenient:

  • includeStories: ['simpleStory', 'complexStory']
  • includeStories: /.*Story$/
  • excludeStories: ['simpleData', 'complexData']
  • excludeStories: /.*Data$/