Web tooling storybook

Storybook Patterns

Quick Guide: Storybook is a component workshop for building and documenting UI in isolation. Use CSF 3.0 format with typed meta and story objects. Define component variants via args. Use play functions for interaction testing. Enable autodocs for automatic documentation. Configure addons in .storybook/main.ts.

---

<critical_requirements>

CRITICAL: Before Using This Skill

All code must follow project conventions in CLAUDE.md (kebab-case, named exports, import ordering, import type, named constants)

(You MUST use CSF 3.0 format with satisfies Meta<typeof Component> for type-safe story metadata)

(You MUST define a default meta export with component property - stories without component won't render)

(You MUST use args for defining props - NOT rendering components with hardcoded props)

(You MUST use play functions with @storybook/test utilities for interaction testing - NOT custom event firing)

(You MUST use named exports for stories - default export is reserved for meta object)

</critical_requirements>

---

Auto-detection: Storybook, .stories.tsx, .stories.ts, CSF, Component Story Format, meta, Meta, StoryObj, args, argTypes, play function, autodocs, @storybook/test, @storybook/addon-essentials

When to use:

• Developing UI components in isolation without full application context
• Creating interactive documentation for component libraries
• Testing component interactions and visual states
• Building design systems with comprehensive examples
• Generating automatic API documentation from TypeScript props
• Visual regression testing

When NOT to use:

• E2E user flow testing spanning multiple pages (use your E2E tool)
• Unit testing pure functions without UI (use your test runner directly)
• Integration testing with real backend services
• Performance testing and load testing

Key patterns covered:

• CSF 3.0 story format with TypeScript
• Args and ArgTypes for props control
• Play functions for interaction testing
• Autodocs for automatic documentation
• MDX for custom documentation pages
• Decorators and parameters
• Addon configuration and customization
• Visual testing integration

Detailed Resources:

• For code examples, see examples/ folder:
  • examples/core.md - CSF 3.0 format, args, controls
  • examples/docs.md - Autodocs, MDX documentation
  • examples/testing.md - Play functions, interaction testing
  • examples/addons.md - Addon configuration
• For decision frameworks and anti-patterns, see reference.md

---

<philosophy>

Philosophy

Storybook enables component-driven development - building UI from the bottom up, starting with basic components and progressively combining them into complex interfaces.

Core Principles:

1. Isolation - Develop components without needing the full application, database, or authentication
2. Documentation - Stories serve as living documentation that stays in sync with code
3. Testing - Use stories as test fixtures for interaction, visual, and accessibility testing
4. Collaboration - Designers, developers, and stakeholders can review components independently

The Story Paradigm:

A "story" captures a specific state of a component. Each story represents one meaningful variation - a button's primary state, disabled state, loading state, etc. Stories are not test cases; they are documented examples.

When to use Storybook:

• Building component libraries or design systems
• Developing UI in parallel with backend work
• Creating documentation for component APIs
• Visual testing and regression detection
• Reviewing UI changes in pull requests

When NOT to use:

• For user journey testing (use E2E tools)
• For testing business logic without UI
• For components that require full application context

</philosophy>

---

<patterns>

Core Patterns

Pattern 1: CSF 3.0 Story Format

Component Story Format 3.0 is the standard for writing stories. It uses typed objects for maximum type safety.

Basic Story Structure

// button.stories.tsx
import type { Meta, StoryObj } from "@storybook/react";
import { Button } from "./button";

// Meta object describes the component
const meta = {
  title: "Components/Button",
  component: Button,
  tags: ["autodocs"],
  parameters: {
    layout: "centered",
  },
  argTypes: {
    onClick: { action: "clicked" },
  },
} satisfies Meta<typeof Button>;

export default meta;
type Story = StoryObj<typeof meta>;

// Each named export is a story
export const Primary: Story = {
  args: {
    variant: "primary",
    children: "Primary Button",
  },
};

export const Secondary: Story = {
  args: {
    variant: "secondary",
    children: "Secondary Button",
  },
};

export const Disabled: Story = {
  args: {
    variant: "primary",
    children: "Disabled Button",
    disabled: true,
  },
};

Why good: satisfies Meta<typeof Button> provides full type checking while allowing inference, stories are simple objects, tags: ["autodocs"] generates documentation automatically

---

Pattern 2: Args and ArgTypes Configuration

Args define prop values for stories. ArgTypes configure controls in the Storybook UI.

ArgTypes Configuration

const meta = {
  title: "Components/Card",
  component: Card,
  argTypes: {
    // Control type for enums
    variant: {
      control: { type: "select" },
      options: ["default", "outline", "filled"],
      description: "Visual variant of the card",
    },
    // Control type for booleans
    isLoading: {
      control: { type: "boolean" },
      description: "Shows loading skeleton",
    },
    // Control type for strings
    title: {
      control: { type: "text" },
      description: "Card title text",
    },
    // Range control for numbers
    padding: {
      control: { type: "range", min: 0, max: 64, step: 4 },
      description: "Padding in pixels",
    },
    // Color picker
    backgroundColor: {
      control: { type: "color" },
    },
    // Hide from controls
    internalId: {
      table: { disable: true },
    },
    // Action handler
    onClose: {
      action: "closed",
    },
  },
} satisfies Meta<typeof Card>;

Default Args

const meta = {
  title: "Components/Input",
  component: Input,
  // Default args applied to all stories
  args: {
    placeholder: "Enter text...",
    disabled: false,
  },
} satisfies Meta<typeof Input>;

export default meta;
type Story = StoryObj<typeof meta>;

// Story inherits default args, only overrides what changes
export const Default: Story = {};

export const WithLabel: Story = {
  args: {
    label: "Email address",
  },
};

export const Disabled: Story = {
  args: {
    disabled: true,
  },
};

Why good: centralized defaults reduce duplication, argTypes provide interactive documentation, control types match prop types for intuitive editing

---

Pattern 3: Decorators for Context

Decorators wrap stories with providers, layouts, or styling context.

Component-Level Decorators

const meta = {
  title: "Components/Modal",
  component: Modal,
  decorators: [
    // Add padding around the story
    (Story) => (
      <div style={{ padding: "3rem" }}>
        <Story />
      </div>
    ),
    // Wrap with theme provider
    (Story) => (
      <ThemeProvider theme="light">
        <Story />
      </ThemeProvider>
    ),
  ],
} satisfies Meta<typeof Modal>;

Global Decorators

// .storybook/preview.tsx
import type { Preview } from "@storybook/react";
import { ThemeProvider } from "../src/theme-provider";

const preview: Preview = {
  decorators: [
    (Story) => (
      <ThemeProvider>
        <Story />
      </ThemeProvider>
    ),
  ],
};

export default preview;

Story-Level Decorators

export const InDarkMode: Story = {
  decorators: [
    (Story) => (
      <div className="dark" style={{ background: "#1a1a1a", padding: "2rem" }}>
        <Story />
      </div>
    ),
  ],
  args: {
    children: "Dark Mode Button",
  },
};

Why good: decorators keep component code clean, global decorators ensure consistent context, story decorators allow specific variations

---

Pattern 4: Parameters for Story Configuration

Parameters configure Storybook features and addons per story, component, or globally.

Common Parameters

const meta = {
  title: "Components/Dialog",
  component: Dialog,
  parameters: {
    // Layout options: centered, fullscreen, padded
    layout: "centered",

    // Background options
    backgrounds: {
      default: "light",
      values: [
        { name: "light", value: "#ffffff" },
        { name: "dark", value: "#1a1a1a" },
        { name: "brand", value: "#0066ff" },
      ],
    },

    // Viewport configuration
    viewport: {
      defaultViewport: "mobile1",
    },

    // Disable specific controls panel
    controls: {
      expanded: true,
      sort: "requiredFirst",
    },

    // Documentation page order
    docs: {
      description: {
        component: "A modal dialog for user confirmations.",
      },
    },
  },
} satisfies Meta<typeof Dialog>;

Story-Specific Parameters

export const MobileView: Story = {
  parameters: {
    viewport: {
      defaultViewport: "mobile1",
    },
    chromatic: {
      viewports: [320, 768],
    },
  },
};

export const FullPage: Story = {
  parameters: {
    layout: "fullscreen",
  },
};

Why good: parameters configure addon behavior declaratively, can be set at any level (global, component, story), consistent API across all addons

---

Pattern 5: Play Functions for Interaction Testing

Play functions enable interaction testing within stories using the @storybook/test utilities.

Basic Interaction Testing

import type { Meta, StoryObj } from "@storybook/react";
import { expect, fn, userEvent, within } from "@storybook/test";
import { LoginForm } from "./login-form";

const meta = {
  title: "Forms/LoginForm",
  component: LoginForm,
  args: {
    onSubmit: fn(),
  },
} satisfies Meta<typeof LoginForm>;

export default meta;
type Story = StoryObj<typeof meta>;

export const FilledForm: Story = {
  play: async ({ canvasElement, args }) => {
    const canvas = within(canvasElement);

    // Find elements
    const emailInput = canvas.getByLabelText(/email/i);
    const passwordInput = canvas.getByLabelText(/password/i);
    const submitButton = canvas.getByRole("button", { name: /sign in/i });

    // Interact with form
    await userEvent.type(emailInput, "[email protected]");
    await userEvent.type(passwordInput, "password123");
    await userEvent.click(submitButton);

    // Assert callback was called
    await expect(args.onSubmit).toHaveBeenCalledWith({
      email: "[email protected]",
      password: "password123",
    });
  },
};

Composing Play Functions

export const Default: Story = {
  play: async ({ canvasElement }) => {
    const canvas = within(canvasElement);
    await expect(canvas.getByRole("button")).toBeInTheDocument();
  },
};

export const Clicked: Story = {
  play: async (context) => {
    // Run the Default story's play function first
    await Default.play?.(context);

    const canvas = within(context.canvasElement);
    const button = canvas.getByRole("button");

    await userEvent.click(button);
    await expect(button).toHaveAttribute("data-state", "pressed");
  },
};

See examples/testing.md for more play function patterns.

Why good: tests run in actual browser environment, reuses Testing Library queries for consistency, play functions double as documentation

---

Pattern 6: Render Functions for Complex Stories

Use the render property when you need more control than args provides.

Custom Render Function

export const WithMultipleItems: Story = {
  render: (args) => (
    <List>
      <ListItem {...args} title="First Item" />
      <ListItem {...args} title="Second Item" />
      <ListItem {...args} title="Third Item" />
    </List>
  ),
  args: {
    isSelected: false,
  },
};

Render with Hooks

export const Controlled: Story = {
  render: function Render(args) {
    const [isOpen, setIsOpen] = useState(false);

    return (
      <div>
        <Button onClick={() => setIsOpen(true)}>Open Dialog</Button>
        <Dialog {...args} open={isOpen} onClose={() => setIsOpen(false)} />
      </div>
    );
  },
  args: {
    title: "Controlled Dialog",
  },
};

Why good: render functions allow complex compositions, named functions enable hooks, args still control individual props

---

Pattern 7: Story Organization

Organize stories with a clear hierarchy that reflects your component structure.

Title Hierarchy

// Organized by category
const meta = {
  title: "Components/Forms/Input", // Creates nested navigation
  component: Input,
} satisfies Meta<typeof Input>;

// Alternative structures:
// "Design System/Atoms/Button"
// "Pages/Dashboard/Header"
// "Features/Authentication/LoginForm"

Naming Conventions

// Good: Descriptive story names
export const Default: Story = {};
export const WithIcon: Story = {};
export const Disabled: Story = {};
export const Loading: Story = {};
export const WithValidationError: Story = {};

// Bad: Unclear names
export const Story1: Story = {};
export const Test: Story = {};

Story Order

const meta = {
  title: "Components/Button",
  component: Button,
  parameters: {
    docs: {
      // Control story order in docs
      page: () => (
        <>
          <Title />
          <Subtitle />
          <Description />
          <Primary />
          <Controls />
          <Stories />
        </>
      ),
    },
  },
} satisfies Meta<typeof Button>;

Why good: hierarchical titles create intuitive navigation, descriptive names serve as documentation, consistent patterns across the codebase

</patterns>

---

<integration>

Integration Guide

Works with your component framework:

• Stories import and render your actual components
• TypeScript types flow from component props to story args
• Your styling solution works as-is in Storybook (CSS modules, utility classes, etc.)

Works with your testing tools:

• Play functions use Testing Library queries
• Stories can be imported as test fixtures in your test runner
• Visual testing tools use stories as test cases

Works with your CI/CD:

• build-storybook creates static site for deployment
• Storybook test addon integrates with CI for interaction tests
• Visual regression tools integrate via CI

Boundary guidance:

• Storybook handles: component isolation, documentation, controls, interaction testing, visual states
• Your E2E tool handles: full user journeys, navigation flows
• Your styling solution handles: actual CSS implementation

</integration>

---

<red_flags>

RED FLAGS

High Priority Issues:

• Using default export for stories - Default export is reserved for meta; stories must be named exports
• Hardcoding props in JSX instead of using args - Defeats the purpose of controls; makes stories non-interactive
• Missing component property in meta - Stories won't render correctly; autodocs won't work
• Using fireEvent instead of userEvent in play functions - Doesn't simulate real user behavior
• Importing from @storybook/testing-library - Deprecated; use @storybook/test instead
• Using argTypesRegex for play function handlers - Implicit actions cannot be used in play functions; use explicit fn()

Medium Priority Issues:

• Not using satisfies Meta<typeof Component> - Loses type safety on story args
• Putting business logic in play functions - Play functions are for interaction, not logic testing
• Missing tags: ["autodocs"] - Won't generate automatic documentation
• Overly complex render functions - If render is complex, component API may need refactoring

Common Mistakes:

• Forgetting to await userEvent actions in play functions
• Using any type instead of StoryObj<typeof meta>
• Not setting up global decorators for providers (ThemeProvider, etc.)
• Putting test assertions in stories without play functions

Gotchas & Edge Cases:

• args are serializable - functions must use action or fn() from @storybook/test
• Play functions run after render - use waitFor for async content
• Decorators run outermost to innermost - order matters for context
• canvas.getByRole uses Testing Library - same accessibility rules apply
• Hot reload preserves args state - may need manual refresh for some changes
• Storybook 8 uses react-docgen by default (not react-docgen-typescript) - imported types may not be extracted
• In Storybook 8.2+, use initialGlobals instead of deprecated globals in preview.ts
• Built-in tags: dev (sidebar visibility), test (test inclusion), autodocs (docs generation) - use !tag to remove inherited tags
• Storybook test addon (8.4+) is recommended over legacy test-runner for Vite projects - provides Storybook UI integration
• Storybook 10 is ESM-only - requires "type": "module" in package.json and Node 20.16+

</red_flags>

---

<critical_reminders>

CRITICAL REMINDERS

All code must follow project conventions in CLAUDE.md

(You MUST use CSF 3.0 format with satisfies Meta<typeof Component> for type-safe story metadata)

(You MUST define a default meta export with component property - stories without component won't render)

(You MUST use args for defining props - NOT rendering components with hardcoded props)

(You MUST use play functions with @storybook/test utilities for interaction testing - NOT custom event firing)

(You MUST use named exports for stories - default export is reserved for meta object)

Failure to follow these rules will produce untestable stories, missing documentation, and broken controls.

</critical_reminders>