Storybook

Build component stories with proper args, controls, decorators, and testing patterns.

CSF Format (Component Story Format)

• Default export is component meta—title, component, args, decorators
• Named exports are stories—each export becomes a story in sidebar
• satisfies Meta<typeof Component> for TypeScript type checking
• CSF3 uses object syntax, not functions—export const Primary = { args: {...} }

Args vs ArgTypes

• args are actual prop values passed to component—args: { label: 'Click me' }
• argTypes configure controls UI—argTypes: { size: { control: 'select', options: ['sm', 'lg'] } }
• Default args in meta apply to all stories—override in individual stories
• argTypes: { onClick: { action: 'clicked' } } logs events in Actions panel

Controls

• Auto-inferred from TypeScript props—boolean becomes toggle, string becomes text input
• Override control type: argTypes: { color: { control: 'color' } }
• Disable control: argTypes: { children: { control: false } }
• Options for select: control: { type: 'select' }, options: ['a', 'b', 'c']

Decorators

• Wrap stories with context—providers, layout wrappers, theme
• Component-level in meta: decorators: [(Story) => <Provider><Story /></Provider>]
• Global in .storybook/preview.js: applies to all stories
• Order matters—later decorators wrap earlier ones

Play Functions

• Interactive testing within story: play: async ({ canvasElement }) => {...}
• Use @storybook/testing-library for queries—within(canvasElement).getByRole()
• await userEvent.click(button) for interactions
• expect(element).toBeVisible() for assertions—tests run in browser

Actions

• argTypes: { onClick: { action: 'clicked' } } auto-logs to Actions panel
• Or import: import { action } from '@storybook/addon-actions'
• Use fn() from @storybook/test in Storybook 8+ for spying in play functions
• Actions help verify event handlers without manual console.log

Story Organization

• Title path creates hierarchy: title: 'Components/Forms/Button'
• Stories appear in order of export—put Primary first
• tags: ['autodocs'] generates docs page automatically
• parameters: { docs: { description: { story: 'text' } } } adds story description

Common Patterns

• Default state: export const Default = {}
• With all props: export const WithIcon = { args: { icon: <Icon /> } }
• Edge cases: Empty, Loading, Error, Disabled states as separate stories
• Responsive: Use viewport addon parameters per story

Render Functions

• Custom render: render: (args) => <Wrapper><Component {...args} /></Wrapper>
• Access context in render: render: (args, { globals }) => ...
• Useful when story needs different JSX structure than default
• Prefer decorators for wrapping, render for restructuring

Configuration

• .storybook/main.js: addons, framework, stories glob patterns
• .storybook/preview.js: global decorators, parameters, argTypes
• Stories glob: stories: ['../src/**/*.stories.@(js|jsx|ts|tsx)']
• Static assets: staticDirs: ['../public'] for images/fonts

Common Mistakes

• Forgetting to install addon AND add to main.js addons array
• Using storiesOf API—deprecated, use CSF exports
• Missing component in meta—controls won't auto-generate
• Decorators returning Story without calling it: (Story) => <Story /> not (Story) => Story