Inquirer Patterns

Inquirer Patterns

Comprehensive interactive prompt patterns for building CLI tools with rich user input capabilities. Provides templates for text, list, checkbox, password, autocomplete, and conditional questions in both Node.js and Python.

Instructions

When Building Interactive CLI Prompts

1. Identify prompt type needed:

   • Text input: Simple string input
   • List selection: Single choice from options
   • Checkbox: Multiple selections
   • Password: Secure input (hidden)
   • Autocomplete: Type-ahead suggestions
   • Conditional: Questions based on previous answers

2. Choose language:

   • Node.js: Use templates in templates/nodejs/
   • Python: Use templates in templates/python/

3. Select appropriate template:

   • text-prompt.js/py - Basic text input
   • list-prompt.js/py - Single selection list
   • checkbox-prompt.js/py - Multiple selections
   • password-prompt.js/py - Secure password input
   • autocomplete-prompt.js/py - Type-ahead suggestions
   • conditional-prompt.js/py - Dynamic questions based on answers
   • comprehensive-example.js/py - All patterns combined

4. Install required dependencies:

   • Node.js: Run scripts/install-nodejs-deps.sh
   • Python: Run scripts/install-python-deps.sh

5. Test prompts:

   • Use examples in examples/nodejs/ or examples/python/
   • Run validation script: scripts/validate-prompts.sh

6. Customize for your CLI:

   • Copy relevant template sections
   • Modify questions, choices, validation
   • Add custom conditional logic

Node.js Implementation

Library: inquirer (v9.x)

Installation:

npm install inquirer

Basic Usage:

import inquirer from 'inquirer';

const answers = await inquirer.prompt([
  {
    type: 'input',
    name: 'username',
    message: 'Enter your username:',
    validate: (input) => input.length > 0 || 'Username required'
  }
]);

console.log(`Hello, ${answers.username}!`);

Python Implementation

Library: questionary (v2.x)

Installation:

pip install questionary

Basic Usage:

import questionary

username = questionary.text(
    "Enter your username:",
    validate=lambda text: len(text) > 0 or "Username required"
).ask()

print(f"Hello, {username}!")

Available Templates

Node.js Templates (templates/nodejs/)

1. text-prompt.js - Text input with validation
2. list-prompt.js - Single selection from list
3. checkbox-prompt.js - Multiple selections
4. password-prompt.js - Secure password input with confirmation
5. autocomplete-prompt.js - Type-ahead with fuzzy search
6. conditional-prompt.js - Dynamic questions based on answers
7. comprehensive-example.js - Complete CLI questionnaire

Python Templates (templates/python/)

1. text_prompt.py - Text input with validation
2. list_prompt.py - Single selection from list
3. checkbox_prompt.py - Multiple selections
4. password_prompt.py - Secure password input with confirmation
5. autocomplete_prompt.py - Type-ahead with fuzzy search
6. conditional_prompt.py - Dynamic questions based on answers
7. comprehensive_example.py - Complete CLI questionnaire

Prompt Types Reference

Text Input

• Use for: Names, emails, URLs, paths, free-form text
• Features: Validation, default values, transform
• Node.js: { type: 'input' }
• Python: questionary.text()

List Selection

• Use for: Single choice from predefined options
• Features: Arrow key navigation, search filtering
• Node.js: { type: 'list' }
• Python: questionary.select()

Checkbox

• Use for: Multiple selections from options
• Features: Space to toggle, Enter to confirm
• Node.js: { type: 'checkbox' }
• Python: questionary.checkbox()

Password

• Use for: Sensitive input (credentials, tokens)
• Features: Hidden input, confirmation, validation
• Node.js: { type: 'password' }
• Python: questionary.password()

Autocomplete

• Use for: Large option lists with search
• Features: Type-ahead, fuzzy matching, suggestions
• Node.js: inquirer-autocomplete-prompt plugin
• Python: questionary.autocomplete()

Conditional Questions

• Use for: Dynamic forms based on previous answers
• Features: Skip logic, dependent questions, branching
• Node.js: when property in question config
• Python: Conditional logic with if statements

Validation Patterns

Email Validation

// Node.js
validate: (input) => {
  const regex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
  return regex.test(input) || 'Invalid email address';
}

# Python
def validate_email(text):
    import re
    regex = r'^[^\s@]+@[^\s@]+\.[^\s@]+$'
    return bool(re.match(regex, text)) or "Invalid email address"

questionary.text("Email:", validate=validate_email).ask()

Non-Empty Validation

// Node.js
validate: (input) => input.length > 0 || 'This field is required'

# Python
questionary.text("Name:", validate=lambda t: len(t) > 0 or "Required").ask()

Numeric Range Validation

// Node.js
validate: (input) => {
  const num = parseInt(input);
  return (num >= 1 && num <= 100) || 'Enter number between 1-100';
}

# Python
def validate_range(text):
    try:
        num = int(text)
        return 1 <= num <= 100 or "Enter number between 1-100"
    except ValueError:
        return "Invalid number"

questionary.text("Number:", validate=validate_range).ask()

Examples

Example 1: Project Initialization Wizard

Use case: Interactive CLI for scaffolding new projects

// Node.js - See examples/nodejs/project-init.js
const answers = await inquirer.prompt([
  {
    type: 'input',
    name: 'projectName',
    message: 'Project name:',
    validate: (input) => /^[a-z0-9-]+$/.test(input) || 'Invalid project name'
  },
  {
    type: 'list',
    name: 'framework',
    message: 'Choose framework:',
    choices: ['React', 'Vue', 'Angular', 'Svelte']
  },
  {
    type: 'checkbox',
    name: 'features',
    message: 'Select features:',
    choices: ['TypeScript', 'ESLint', 'Prettier', 'Testing']
  }
]);

# Python - See examples/python/project_init.py
import questionary

project_name = questionary.text(
    "Project name:",
    validate=lambda t: bool(re.match(r'^[a-z0-9-]+$', t)) or "Invalid name"
).ask()

framework = questionary.select(
    "Choose framework:",
    choices=['React', 'Vue', 'Angular', 'Svelte']
).ask()

features = questionary.checkbox(
    "Select features:",
    choices=['TypeScript', 'ESLint', 'Prettier', 'Testing']
).ask()

Example 2: Conditional Question Flow

Use case: Dynamic questions based on previous answers

// Node.js - See examples/nodejs/conditional-flow.js
const questions = [
  {
    type: 'confirm',
    name: 'useDatabase',
    message: 'Use database?',
    default: true
  },
  {
    type: 'list',
    name: 'dbType',
    message: 'Database type:',
    choices: ['PostgreSQL', 'MySQL', 'MongoDB', 'SQLite'],
    when: (answers) => answers.useDatabase
  },
  {
    type: 'input',
    name: 'dbHost',
    message: 'Database host:',
    default: 'localhost',
    when: (answers) => answers.useDatabase && answers.dbType !== 'SQLite'
  }
];

# Python - See examples/python/conditional_flow.py
use_database = questionary.confirm("Use database?", default=True).ask()

if use_database:
    db_type = questionary.select(
        "Database type:",
        choices=['PostgreSQL', 'MySQL', 'MongoDB', 'SQLite']
    ).ask()

    if db_type != 'SQLite':
        db_host = questionary.text(
            "Database host:",
            default="localhost"
        ).ask()

Example 3: Password with Confirmation

Use case: Secure password input with validation and confirmation

// Node.js - See examples/nodejs/password-confirm.js
const answers = await inquirer.prompt([
  {
    type: 'password',
    name: 'password',
    message: 'Enter password:',
    validate: (input) => input.length >= 8 || 'Password must be 8+ characters'
  },
  {
    type: 'password',
    name: 'confirmPassword',
    message: 'Confirm password:',
    validate: (input, answers) => {
      return input === answers.password || 'Passwords do not match';
    }
  }
]);

# Python - See examples/python/password_confirm.py
password = questionary.password(
    "Enter password:",
    validate=lambda t: len(t) >= 8 or "Password must be 8+ characters"
).ask()

confirm = questionary.password(
    "Confirm password:",
    validate=lambda t: t == password or "Passwords do not match"
).ask()

Scripts

Install Dependencies

Node.js:

./scripts/install-nodejs-deps.sh
# Installs: inquirer, inquirer-autocomplete-prompt

Python:

./scripts/install-python-deps.sh
# Installs: questionary, prompt_toolkit

Validate Prompts

./scripts/validate-prompts.sh [nodejs|python]
# Tests all templates and examples

Generate Prompt Code

./scripts/generate-prompt.sh --type [text|list|checkbox|password] --lang [js|py]
# Generates boilerplate prompt code

Best Practices

1. Always validate user input - Prevent invalid data early
2. Provide clear messages - Use descriptive prompt text
3. Set sensible defaults - Reduce friction for common cases
4. Use conditional logic - Skip irrelevant questions
5. Group related questions - Keep context together
6. Handle Ctrl+C gracefully - Catch interrupts and exit cleanly
7. Test interactively - Run examples to verify UX
8. Provide help text - Add descriptions for complex prompts

Common Patterns

CLI Configuration Generator

const config = await inquirer.prompt([
  { type: 'input', name: 'appName', message: 'App name:' },
  { type: 'input', name: 'version', message: 'Version:', default: '1.0.0' },
  { type: 'list', name: 'env', message: 'Environment:', choices: ['dev', 'prod'] },
  { type: 'confirm', name: 'debug', message: 'Enable debug?', default: false }
]);

Multi-Step Installation Wizard

# Step 1: Choose components
components = questionary.checkbox(
    "Select components:",
    choices=['Core', 'CLI', 'Web UI', 'API']
).ask()

# Step 2: Configure each component
for component in components:
    print(f"\nConfiguring {component}...")
    # Component-specific questions

Error Recovery

try {
  const answers = await inquirer.prompt(questions);
  // Process answers
} catch (error) {
  if (error.isTtyError) {
    console.error('Prompt could not be rendered in this environment');
  } else {
    console.error('User interrupted prompt');
  }
  process.exit(1);
}

Requirements

• Node.js: v14+ with ESM support
• Python: 3.7+ with pip
• Dependencies:
  • Node.js: inquirer@^9.0.0, inquirer-autocomplete-prompt@^3.0.0
  • Python: questionary@^2.0.0, prompt_toolkit@^3.0.0

Troubleshooting

Node.js Issues

Problem: Error [ERR_REQUIRE_ESM] Solution: Use import instead of require, or add "type": "module" to package.json

Problem: Autocomplete not working Solution: Install inquirer-autocomplete-prompt plugin

Python Issues

Problem: No module named 'questionary' Solution: Run pip install questionary

Problem: Prompt rendering issues Solution: Ensure terminal supports ANSI escape codes

Purpose: Provide reusable interactive prompt patterns for CLI development Load when: Building CLIs with user input, creating interactive questionnaires, implementing wizards