Mermaid Validate CLI

A command-line tool to validate Mermaid diagrams.

📖 Development Guide - Setup, architecture, CI/CD, and contributing information

Installation

npm install mermaid-validate -g

Usage

Validate from File

mermaid-validate validate <filePath> [options]

Validate from String

mermaid-validate validate "<diagram-string>" --string [options]

Validate Markdown File

mermaid-validate validate-md <markdown-file> [options]

Using NPX (Recommended)

# Validate file
npx mermaid-validate validate <filePath> [options]

# Validate string
npx mermaid-validate validate "<diagram-string>" --string [options]

Examples

# Validate a diagram file
mermaid-validate validate diagram.mmd

# Validate a diagram string directly
mermaid-validate validate "flowchart TD; A-->B;" --string

# Using NPX with file
npx mermaid-validate validate flowchart.mmd

# Using NPX with string
npx mermaid-validate validate "sequenceDiagram; A->>B: Hello" --string

# Specify diagram type (optional)
mermaid-validate validate "pie title Pets; Dogs: 50; Cats: 30" --string --type pie

# Validate all Mermaid diagrams in a Markdown file
mermaid-validate validate-md README.md

# Validate with fail-fast (stop on first error)
mermaid-validate validate-md docs/architecture.md --fail-fast

# Using NPX with markdown
npx mermaid-validate validate-md documentation.md

Programmatic Usage

import { validate } from 'mermaid-validate';

const result = await validate('flowchart TD; A-->B;', 'flowchart');
console.log(result); // { isValid: true }

const invalidResult = await validate('flowchart TD; A--B;', 'flowchart');
console.log(invalidResult); // { isValid: false, error: "..." }

Supported Diagram Types

The validator supports all Mermaid diagram types including:

• Flowcharts
• Sequence diagrams
• Class diagrams
• State diagrams
• Entity relationship diagrams
• User journey diagrams
• Gantt charts
• Pie charts
• Git graphs
• And more...

Corporate Environment Support

This CLI includes automatic support for corporate NPM registries. If you're working in a corporate environment where packages are downloaded from internal registries, the tool can automatically fix package-lock.json files to use public NPM registry URLs.

Quick Setup

1. Copy the environment template:

   cp .env.example .env

2. Edit .env with your corporate registry URL:

   CORPORATE_REGISTRY=https://your-company.com/npm/

3. The pre-commit hook will automatically fix registry URLs when you commit.

For detailed configuration options, see DEVELOPMENT.md.

Development

For development setup, architecture details, CI/CD configuration, and contributing guidelines, see DEVELOPMENT.md.

Quick start for developers:

git clone git@github.com:cloud-on-prem/mermaid-validator.git
cd mermaid-validator
npm install
npm test

License

Apache 2.0