Gluegun Patterns

Gluegun CLI Toolkit Patterns

Provides comprehensive patterns and templates for building TypeScript-powered CLI applications using the Gluegun toolkit. Gluegun offers parameters, templates, filesystem operations, HTTP utilities, prompts, and extensible plugin architecture.

Core Capabilities

Gluegun provides these essential toolbox features:

1. Parameters - Command-line arguments and options parsing
2. Template - EJS-based file generation from templates
3. Filesystem - File and directory operations (fs-jetpack)
4. System - Execute external commands and scripts
5. HTTP - API interactions with axios/apisauce
6. Prompt - Interactive user input with enquirer
7. Print - Colorful console output with colors/ora
8. Patching - Modify existing file contents
9. Semver - Version string manipulation
10. Plugin System - Extensible command architecture

Instructions

Building a Basic CLI

1. Initialize Gluegun CLI structure:

   import { build } from 'gluegun'
   
   const cli = build()
     .brand('mycli')
     .src(__dirname)
     .plugins('./node_modules', { matching: 'mycli-*', hidden: true })
     .help()
     .version()
     .create()
   

2. Create command structure:

   • Commands go in src/commands/ directory
   • Each command exports a GluegunCommand object
   • Use templates from templates/ directory
   • Reference template: templates/commands/basic-command.ts.ejs

3. Implement command with toolbox:

   module.exports = {
     name: 'generate',
     run: async (toolbox) => {
       const { template, print, parameters } = toolbox
       const name = parameters.first
   
       await template.generate({
         template: 'model.ts.ejs',
         target: `src/models/${name}.ts`,
         props: { name }
       })
   
       print.success(`Generated ${name} model`)
     }
   }
   

Template System

1. Template file structure:

   • Store templates in templates/ directory
   • Use EJS syntax: <%= variable %>, <%- unescaped %>
   • Reference: templates/toolbox/template-examples.ejs

2. Generate files from templates:

   await template.generate({
     template: 'component.tsx.ejs',
     target: `src/components/${name}.tsx`,
     props: { name, style: 'functional' }
   })
   

3. Helper functions:

   • props.camelCase - camelCase conversion
   • props.pascalCase - PascalCase conversion
   • props.kebabCase - kebab-case conversion
   • Reference: scripts/template-helpers.ts

Filesystem Operations

1. Common operations (fs-jetpack):

   // Read/write files
   const config = await filesystem.read('config.json', 'json')
   await filesystem.write('output.txt', data)
   
   // Directory operations
   await filesystem.dir('src/components')
   const files = filesystem.find('src', { matching: '*.ts' })
   
   // Copy/move/remove
   await filesystem.copy('template', 'output')
   await filesystem.move('old.txt', 'new.txt')
   await filesystem.remove('temp')
   

2. Path utilities:

   filesystem.path('src', 'commands') // Join paths
   filesystem.cwd() // Current directory
   filesystem.separator // OS-specific separator
   

HTTP Utilities

1. API interactions:

   const api = http.create({
     baseURL: 'https://api.example.com',
     headers: { 'Authorization': 'Bearer token' }
   })
   
   const response = await api.get('/users')
   const result = await api.post('/users', { name: 'John' })
   

2. Error handling:

   if (!response.ok) {
     print.error(response.problem)
     return
   }
   

Interactive Prompts

1. User input patterns:

   // Ask question
   const result = await prompt.ask({
     type: 'input',
     name: 'name',
     message: 'What is your name?'
   })
   
   // Confirm action
   const proceed = await prompt.confirm('Continue?')
   
   // Select from list
   const choice = await prompt.ask({
     type: 'select',
     name: 'framework',
     message: 'Choose framework:',
     choices: ['React', 'Vue', 'Angular']
   })
   

2. Multi-select and complex forms:

   • Reference: examples/prompts/multi-select.ts
   • See: templates/toolbox/prompt-examples.ts.ejs

Plugin Architecture

1. Create extensible plugins:

   // Plugin structure
   export default (toolbox) => {
     const { filesystem, template } = toolbox
   
     // Add custom extension
     toolbox.myFeature = {
       doSomething: () => { /* ... */ }
     }
   }
   

2. Load plugins:

   cli.plugins('./node_modules', { matching: 'mycli-*' })
   cli.plugins('./plugins', { matching: '*.js' })
   

3. Plugin examples:

   • Reference: examples/plugin-system/custom-plugin.ts
   • See: templates/plugins/plugin-template.ts.ejs

Print Utilities

1. Colorful output:

   print.info('Information message')
   print.success('Success message')
   print.warning('Warning message')
   print.error('Error message')
   print.highlight('Highlighted text')
   print.muted('Muted text')
   

2. Spinners and progress:

   const spinner = print.spin('Loading...')
   await doWork()
   spinner.succeed('Done!')
   
   // Or fail
   spinner.fail('Something went wrong')
   

3. Tables and formatting:

   print.table([
     ['Name', 'Age'],
     ['John', '30'],
     ['Jane', '25']
   ])
   

System Commands

1. Execute external commands:

   const output = await system.run('npm install')
   const result = await system.exec('git status')
   
   // Spawn with options
   await system.spawn('npm run build', { stdio: 'inherit' })
   

2. Check command availability:

   const hasGit = await system.which('git')
   

File Patching

1. Modify existing files:

   // Add line after pattern
   await patching.update('package.json', (content) => {
     const pkg = JSON.parse(content)
     pkg.scripts.build = 'tsc'
     return JSON.stringify(pkg, null, 2)
   })
   
   // Insert import statement
   await patching.insert('src/index.ts', 'import { Router } from "express"')
   

Validation Scripts

Use these scripts to validate Gluegun CLI implementations:

• scripts/validate-cli-structure.sh - Check directory structure
• scripts/validate-commands.sh - Verify command format
• scripts/validate-templates.sh - Check template syntax
• scripts/test-cli-build.sh - Run full CLI build test

Templates

Command Templates

• templates/commands/basic-command.ts.ejs - Simple command
• templates/commands/generator-command.ts.ejs - File generator
• templates/commands/api-command.ts.ejs - HTTP interaction

Extension Templates

• templates/extensions/custom-toolbox.ts.ejs - Toolbox extension
• templates/extensions/helper-functions.ts.ejs - Utility functions

Plugin Templates

• templates/plugins/plugin-template.ts.ejs - Plugin structure
• templates/plugins/plugin-with-commands.ts.ejs - Plugin with commands

Toolbox Templates

• templates/toolbox/template-examples.ejs - Template patterns
• templates/toolbox/prompt-examples.ts.ejs - Prompt patterns
• templates/toolbox/filesystem-examples.ts.ejs - Filesystem patterns

Examples

Basic CLI Example

See examples/basic-cli/ for complete working CLI:

• Simple command structure
• Template generation
• User prompts
• File operations

Plugin System Example

See examples/plugin-system/ for extensible architecture:

• Plugin loading
• Custom toolbox extensions
• Command composition

Template Generator Example

See examples/template-generator/ for advanced patterns:

• Multi-file generation
• Conditional templates
• Helper functions

Best Practices

1. Command Organization

   • One command per file
   • Group related commands in subdirectories
   • Use clear, descriptive command names

2. Template Design

   • Keep templates simple and focused
   • Use helper functions for complex logic
   • Document template variables

3. Error Handling

   • Check HTTP response status
   • Validate user input from prompts
   • Provide helpful error messages

4. Plugin Architecture

   • Make plugins optional
   • Document plugin interfaces
   • Version plugin APIs

5. Testing

   • Test commands in isolation
   • Mock filesystem operations
   • Validate template output

Security Considerations

• Never hardcode API keys in templates
• Use environment variables for secrets
• Validate all user input from prompts
• Sanitize file paths from parameters
• Check filesystem permissions before operations

Requirements

• Node.js 14+ or TypeScript 4+
• Gluegun package: npm install gluegun
• EJS for templates (included)
• fs-jetpack for filesystem (included)
• enquirer for prompts (included)

Related Documentation

• Gluegun Official Docs: https://infinitered.github.io/gluegun/
• GitHub Repository: https://github.com/infinitered/gluegun
• EJS Templates: https://ejs.co/
• fs-jetpack: https://github.com/szwacz/fs-jetpack

Purpose: Enable rapid CLI development with Gluegun patterns and best practices Load when: Building CLI tools, command structures, template systems, or plugin architectures