@profullstack/text-type-detection

A lightweight, zero-dependency Node.js module for detecting text format types from strings. Accurately identifies plain text, markdown, ASCII art, code blocks, HTML, JSON, and XML.

Features

- 🎯 Accurate Detection: Uses multiple heuristics to identify text formats
- 🚀 Zero Dependencies: Pure JavaScript implementation
- 📦 ESM Support: Modern ES Module syntax
- 🧪 Well Tested: Comprehensive test coverage with Mocha and Chai
- 🎨 ASCII Art Detection: Recognizes box drawing, Unicode art, ANSI sequences
- 📝 Markdown Support: Detects headings, lists, links, code blocks, and more
- 🔍 Multiple Formats: Supports plain, markdown, ascii, code, html, json, xml

Installation

``bash
pnpm add @profullstack/text-type-detection
`

Or with npm:

`bash
npm install @profullstack/text-type-detection
`

Usage

$3

`javascript
import { detectTextFormat } from '@profullstack/text-type-detection';

const text = '# Hello World\n\nThis is a markdown document.';
const result = detectTextFormat(text);

console.log(result);
// {
// text_format: 'markdown',
// asciiArt: 0.000,
// markdown: 0.180,
// reasons: {
// ascii: [],
// markdown: ['heading'],
// codePenaltyApplied: false
// },
// stats: { lines: 3, mean: 20.67, std: 12.34, symD: 0.05, alpha: 0.75 }
// }
`

$3

#### Plain Text

`javascript
const plainText = 'This is just a simple sentence.';
const result = detectTextFormat(plainText);
console.log(result.text_format); // 'plain'
`

#### Markdown

`javascript
const markdown = # Title

Subtitle

- Item 1
- Item 2

Link;

const result = detectTextFormat(markdown);
console.log(result.text_format); // 'markdown'
console.log(result.reasons.markdown); // ['heading', 'list', 'link']
`

#### ASCII Art

`javascript
const asciiArt = ┌─────────────┐
│ Hello │
│ World │
└─────────────┘;

const result = detectTextFormat(asciiArt);
console.log(result.text_format); // 'ascii'
console.log(result.asciiArt); // 0.680 (high score)
`

#### Code Block

`javascript
const code = \\\javascript
function hello() {
console.log("Hello");
}
\\\;

const result = detectTextFormat(code);
console.log(result.text_format); // 'code'
`

#### HTML

`javascript
const html = '

';
const result = detectTextFormat(html);
console.log(result.text_format); // 'html'
`

#### JSON

`javascript
const json = '{"name": "John", "age": 30}';
const result = detectTextFormat(json);
console.log(result.text_format); // 'json'
`

#### XML

`javascript
const xml = 'test';
const result = detectTextFormat(xml);
console.log(result.text_format); // 'xml'
`

API

$3

Analyzes the input text and returns a detection result object.

#### Parameters

- text (string): The text to analyze

#### Returns

An object with the following properties:

- text_format (string): The detected format type
- 'plain' - Plain text
- 'markdown' - Markdown formatted text
- 'ascii' - ASCII art or box drawing
- 'code' - Code block (fenced)
- 'html' - HTML markup
- 'json' - JSON data
- 'xml' - XML document

- asciiArt (number): ASCII art confidence score (0.000 - 1.000)

- markdown (number): Markdown confidence score (0.000 - 1.000)

- reasons (object): Detailed detection reasons
- ascii (array): List of ASCII art indicators found
- markdown (array): List of markdown features found
- codePenaltyApplied (boolean): Whether code penalty was applied

- stats (object): Statistical analysis of the text
- lines (number): Number of lines
- mean (number): Mean line length
- std (number): Standard deviation of line lengths
- symD (number): Symbol density ratio
- alpha (number): Alphanumeric character ratio

Detection Heuristics

$3

The module detects ASCII art using multiple indicators:

- Unicode Art Characters: Box drawing (U+2500-U+257F), block elements (U+2580-U+259F), Braille patterns (U+2800-U+28FF), geometric shapes (U+25A0-U+25FF)
- Border Lines: Lines composed primarily of border characters (+, -, |, _, =, etc.)
- Consistent Width: Lines with similar lengths (low standard deviation)
- Symbol Density: High ratio of symbols to alphanumeric characters
- Character Runs: Repeated sequences of the same character
- ANSI Sequences: Terminal color codes and formatting
- Trailing Spaces: Intentional spacing for alignment

$3

Markdown features detected include:

- Headings: ATX-style (#) and Setext-style (underlined)
- Lists: Unordered (-/*/+) and ordered (1.)
- Links: text format
- Images: !alt format
- Code: Inline backticks and fenced code blocks
- Blockquotes: Lines starting with >
- Tables: Pipe-separated columns
- Emphasis: Bold (*) and italic ()
- Horizontal Rules: ---, *, ___
- Front Matter: YAML metadata blocks

$3

Code blocks are identified by:

- Fenced code blocks (` or ~~~)
- Indentation patterns
- Programming language keywords
- Syntax characters (semicolons, braces, brackets)

Development

$3

`bash


Clone the repository

git clone https://github.com/profullstack/text-type-detection.git
cd text-type-detection

Install dependencies

pnpm install
`

$3

`bash


Run all tests

pnpm test

Run tests in watch mode

pnpm run test:watch
`

$3

`bash


Run ESLint

pnpm run lint

Fix linting issues

pnpm run lint:fix

Format code with Prettier

pnpm run format
``

Requirements

- Node.js >= 20.0.0
- ESM support

License

MIT

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Author

Profullstack, Inc. https://profullstack.com

Repository

https://github.com/profullstack/text-type-detection