lit-docs-generator

Generate Stencil.js-compatible README documentation for Lit components.

Overview

This package automatically generates comprehensive README.md documentation for your Lit components by parsing TypeScript source files. It extracts metadata from Lit decorators (@customElement, @property, @state, etc.) and JSDoc comments to create well-formatted markdown documentation compatible with Stencil.js documentation format.

Features

• 🔍 Automatic Discovery - Uses glob patterns to find Lit component files
• 📝 Complete Documentation - Extracts properties, events, methods, slots, CSS properties, and CSS parts
• 🎯 Stencil.js Compatible - Generates markdown in Stencil.js documentation format
• 🏷️ JSDoc Support - Supports Stencil.js JSDoc annotations (@slot, @cssprop, @part, etc.)
• 🚀 CLI & API - Use as a command-line tool or programmatically
• 📦 Zero Config - Works out of the box with standard Lit components

Installation

pnpm add -D lit-docs-generator
# or
npm install --save-dev lit-docs-generator
# or
yarn add -D lit-docs-generator

Usage

Use with stencil:

import { litDocsPlugin } from './plugins/lit-docs-plugin';
...
  plugins: [
    litDocsPlugin(),
    cemMergerPlugin(),
  ],
...

Command Line

# Generate docs for all *.lit.ts files
npx lit-docs "**/*.lit.ts"

# With custom pattern
npx lit-docs "src/components/**/*.ts"

# Overwrite existing README files
npx lit-docs "**/*.lit.ts" --overwrite

# Show help
npx lit-docs --help

Programmatic API

import { generateDocs } from 'lit-docs-generator';

await generateDocs({
  pattern: '**/*.lit.ts',
  overwrite: true
});

package.json Script

{
  "scripts": {
    "docs": "lit-docs \"src/components/**/*.ts\" --overwrite"
  }
}

Supported JSDoc Tags

The generator supports the following Stencil.js-compatible JSDoc tags:

Component Level

• @example - Usage examples (can have multiple)
• @dependency - Component dependencies
• @slot [name] - description - Define slots
• @cssprop --property-name - description [default: value] - CSS custom properties
• @part name - description - CSS shadow parts

Property Level

• @required - Mark property as required
• @deprecated [message] - Mark property as deprecated

Method Level

• @param {type} name - description - Parameter documentation
• @returns {type} description - Return value documentation
• @deprecated [message] - Mark method as deprecated

Example Component

import { LitElement, html, css } from 'lit';
import { customElement, property, state } from 'lit/decorators.js';

/**
 * A simple button component with variants and loading state.
 *
 * @slot - Default slot for button content
 * @slot icon - Slot for an icon
 *
 * @cssprop --button-bg - Background color [default: #007bff]
 * @cssprop --button-color - Text color [default: #ffffff]
 * @cssprop --button-border-radius - Border radius [default: 4px]
 *
 * @part button - The button element
 * @part loader - The loading spinner
 *
 * @example
 * <my-button variant="primary">Click me</my-button>
 *
 * @example
 * <my-button loading disabled>
 *   <icon-check slot="icon"></icon-check>
 *   Save
 * </my-button>
 */
@customElement('my-button')
export class MyButton extends LitElement {
  static styles = css`
    :host {
      display: inline-block;
    }
  `;

  /**
   * Button variant style.
   * @required
   */
  @property({ type: String })
  variant: 'primary' | 'secondary' | 'danger' = 'primary';

  /**
   * Disable the button.
   */
  @property({ type: Boolean, reflect: true })
  disabled = false;

  /**
   * Show loading state.
   */
  @property({ type: Boolean })
  loading = false;

  /**
   * Button size.
   */
  @property({ type: String })
  size: 'small' | 'medium' | 'large' = 'medium';

  /**
   * Internal loading state.
   * @internal
   */
  @state()
  private isProcessing = false;

  /**
   * Simulate an async action.
   *
   * @param duration - How long the action takes in milliseconds
   * @returns Promise that resolves when action completes
   */
  async performAction(duration = 1000): Promise<void> {
    this.isProcessing = true;

    await new Promise(resolve => setTimeout(resolve, duration));

    this.isProcessing = false;

    this.dispatchEvent(
      new CustomEvent('action-complete', {
        detail: { duration },
        bubbles: true,
        composed: true
      })
    );
  }

  render() {
    return html`
      <button
        part="button"
        ?disabled="${this.disabled || this.loading}"
        @click="${this._handleClick}"
      >
        ${this.loading ? html`<span part="loader">Loading...</span>` : ''}
        <slot name="icon"></slot>
        <slot></slot>
      </button>
    `;
  }

  private _handleClick() {
    this.dispatchEvent(
      new CustomEvent('button-click', {
        bubbles: true,
        composed: true
      })
    );
  }
}

This will generate a README.md like:

# my-button

A simple button component with variants and loading state.

## Usage

\`\`\`html
<my-button variant="primary">Click me</my-button>
\`\`\`

\`\`\`html
<my-button loading disabled>
  <icon-check slot="icon"></icon-check>
  Save
</my-button>
\`\`\`

## Properties

| Property | Attribute | Description | Type | Default |
| -------- | --------- | ----------- | ---- | ------- |
| `variant` | `variant` | **(required)** Button variant style. | `'primary' \| 'secondary' \| 'danger'` | `'primary'` |
| `disabled` | `disabled` | Disable the button. | `boolean` | `false` |
| `loading` | `loading` | Show loading state. | `boolean` | `false` |
| `size` | `size` | Button size. | `'small' \| 'medium' \| 'large'` | `'medium'` |

## Events

| Event | Description | Type |
| ----- | ----------- | ---- |
| `action-complete` |  _(bubbles, composed)_ | `CustomEvent<any>` |
| `button-click` |  _(bubbles, composed)_ | `CustomEvent<any>` |

## Methods

### `performAction(...)`

Simulate an async action.

#### Signature

\`\`\`typescript
async performAction(duration?: any = 1000): Promise<void>
\`\`\`

#### Parameters

| Name | Type | Description |
| ---- | ---- | ----------- |
| `duration` _(optional)_ | `any` | - How long the action takes in milliseconds Default: `1000` |

#### Returns

Type: `Promise<void>`

Promise that resolves when action completes

## Slots

| Slot | Description |
| ---- | ----------- |
| _(default)_ | Default slot for button content |
| `"icon"` | Slot for an icon |

## CSS Custom Properties

| Name | Description | Default |
| ---- | ----------- | ------- |
| `--button-bg` | Background color | `#007bff` |
| `--button-color` | Text color | `#ffffff` |
| `--button-border-radius` | Border radius | `4px` |

## Shadow Parts

| Part | Description |
| ---- | ----------- |
| `button` | The button element |
| `loader` | The loading spinner |

---

*Built with [Lit](https://lit.dev/)*

Extracted Metadata

The generator automatically extracts:

From Decorators

• @customElement('tag-name') - Component tag name
• @property() - Public properties with types and defaults
• @state() - Internal state (marked as "internal")
• Property options: attribute, reflect, type

From JSDoc

• Component description
• Property descriptions
• Method descriptions and parameter docs
• @slot annotations
• @cssprop / @cssproperty annotations
• @part annotations
• @example usage examples
• @deprecated warnings
• @required markers

From Code

• Events from dispatchEvent() calls
• Event details, bubbles, composed flags
• Public methods with parameters and return types
• Method signatures (sync/async)
• Type information

Generated Documentation Format

Each README includes:

1. Title - Component tag name
2. Description - From class-level JSDoc
3. Usage Examples - From @example tags
4. Properties Table - All public properties
5. Events Table - All dispatched events
6. Methods Section - Public methods with full signatures
7. Slots Table - Available content slots
8. CSS Custom Properties - Themeable CSS variables
9. Shadow Parts - Styleable shadow DOM parts
10. Dependencies - Component dependencies (if specified)

Examples

The package includes three comprehensive example components:

data-grid

A complex data grid with:

• 15 properties (sorting, filtering, pagination)
• 7 events
• 9 public methods
• 4 slots
• 9 CSS custom properties
• 7 CSS shadow parts

wysiwyg-editor

A rich text editor with:

• 16 properties
• 4 events
• 13 public methods
• 3 slots
• 11 CSS custom properties
• 5 CSS shadow parts

tooltip

A flexible tooltip with:

• 10 properties
• 2 events
• 4 public methods
• 2 slots
• 9 CSS custom properties
• 3 CSS shadow parts

Run the examples:

pnpm example

CLI Options

Usage:
  lit-docs [pattern] [options]

Arguments:
  pattern           Glob pattern for files to process (default: **/*.lit.ts)

Options:
  -o, --overwrite   Overwrite existing README.md files
  -h, --help        Show help message
  -v, --version     Show version number

Examples:
  lit-docs "**/*.lit.ts"
  lit-docs "src/components/**/*.ts" --overwrite
  lit-docs "src/my-component.lit.ts"

Requirements

• Components must extend LitElement
• Components must have @customElement decorator
• TypeScript source files

Tips

1. Organize Components - Place each component in its own directory for individual README files
2. Use JSDoc - Add comprehensive JSDoc comments for better documentation
3. Stencil Tags - Use @slot, @cssprop, and @part tags for complete docs
4. Examples - Include multiple @example tags showing different use cases
5. Type Safety - Use TypeScript types for properties and methods

Comparison with Stencil

This generator produces documentation compatible with Stencil.js but works with Lit components:

Feature	Stencil	lit-docs-generator
Component Framework	Stencil	Lit
Doc Format	Markdown	Markdown (same format)
Decorators	@Component, @Prop	@customElement, @property
Auto-generation	Built-in	Standalone tool
JSDoc Tags	Supported	Fully supported

License

MIT

Important disclaimer

This project is generated with AI.

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.