clide-js v0.1.5

Clide-JS

Clide-JS is a Command Line Interface (CLI) framework for node designed to build powerful and flexible command-line applications with ease. It leverages a modular approach, allowing developers to create commands, use hooks for lifecycle management, and extend functionality with plugins.

• Key Features
• Installation
• Quick Start
• Ideal Use Cases
• Running
• Creating Commands
• Creating Plugins
  • Examples
• Routing and Command Resolution
  • Default Commands Directory
  • Command File/Module Resolution Steps
    • Key Points
  • Examples
  • Key Points
• Dynamic Option Handling
  • Benefits
  • Usage in Commands
• CLI Examples
• Reference
• Contributing

Key Features

• Easy-to-use API: Develop commands with a simple and intuitive interface.
• Command Resolution: Dynamically resolves commands from a specified directory, supporting nested and parameterized commands.
• Flexible Lifecycle: Control command execution flow with pre-defined hooks.
• Extensible & Customizable: Adapt the framework to your specific needs through plugins and configuration.
• TypeScript Support: Develop robust and predictable CLI applications with type safety.

Installation

npm install clide-js
# or
yarn add clide-js

Quick Start

1. Import and call the run function

// src/cli.ts
import { run } from 'clide-js';

// Use argv (minus the binary name) and the default commands directory.
run();

// Or pass in your own + some options
run({
  command: 'deploy dev --watch',
  commandsDir: path.join(__dirname, 'modules'),
  initialData: { ... }
  plugins: [help()]
})

2. Use the command function to define your commands in separate files:

// src/commands/hello.ts
import { command } from 'clide-js';

export default command({
  description: 'Say hello!',
  options: {
    name: {
      description: 'The name to greet',
      type: 'string',
      alias: ['n'],
      default: 'World',
    },
  },
  handler: async ({ context, end, next, options }) => {
    // Use the options getter to dynamically retrieve option values.
    const name = options.name({
      prompt: 'Enter your name',
    });

    const message = `Hello, ${name}!`;

    // Use the client to log messages or show arbitrary prompts
    context.client.log(message);

    // Send some data to the next command
    next(message);

    // Or end the command and return some data
    end(message);
  },
});

3. (Optional) Create plugins to extend the framework:

import { Plugin } from 'clide-js';

export function logger(): Plugin {
  return {
    name: 'logger',
    version: '1.0.0',
    description: 'Logs the result of each execution step.',
    init: ({ client, commandString, hooks }) => {
      client.log('🪵 Received command:', commandString);

      hooks.on('beforeNext', ({ data, state }) => {
        client.log('🪵 Next:', {
          commandName: state.command.commandName,
          commandTokens: state.command.commandTokens,
          commandPath: state.command.commandPath,
          params: state.params,
          data: state.data,
        });
      });

      hooks.on('beforeEnd', ({ data, state }) => {
        log('🪵 End:', {
          commandName: state.command.commandName,
          commandTokens: state.command.commandTokens,
          commandPath: state.command.commandPath,
          params: state.params,
          data: state.data,
        });
      });

      // return true to indicate successful initialization
      return true;
    },
  };
}

Ideal Use Cases

Clide-JS is ideal for developers looking to create efficient, maintainable CLI applications with minimal fuss. It offers the right balance of functionality and ease-of-use, making it a practical choice for both simple scripts and more elaborate command-line tools.

• Build complex CLI applications with nested commands and subcommands.
• Develop interactive and dynamic CLI experiences.
• Integrate with other tools and services through plugins.
• Create reusable and modular command components.

Running

Clide-JS is designed to be straightforward to run. The primary entry point is the run function, which orchestrates the command execution flow. It parses and executes commands based on your configuration, handles plugins, and utilizes hooks for lifecycle management.

The run function takes an optional configuration object allowing you to specify commands, plugins, and hooks. This level of customization makes it adaptable to various CLI application requirements.

For detailed API information on the run function, please refer to the Typedoc reference.

Creating Commands

In Clide-JS, commands are the building blocks of your CLI application. Each command can have its description, options, and a handler function where the command's logic resides. Clide-JS allows for dynamic command resolution, meaning your commands can be organized hierarchically, with support for nested and parameterized commands.

To create a command, use the command factory function. This function takes an object with your command's metadata, options, and the handler function. The handler function, which is where the main logic of your command lives, receives a State object. This object provides access to parsed options, command parameters, and the ability to control the command execution flow.

For a comprehensive guide on creating commands, including handling options and parameters, see the Typedoc reference.

Creating Plugins

Plugins in Clide-JS offer a way to extend and customize the framework's functionality. A plugin is an object that includes metadata (name, version, description) and an init function. This function is called during the CLI application's initialization phase and receives the application's Context. The Context provides access to hooks, commands, and other critical framework components.

You can create plugins to add new features, integrate with external services, modify existing behavior, or inject middleware for advanced use cases. The init function should return a boolean indicating whether the initialization was successful.

For more information on developing plugins, including accessing and modifying the application context, refer to the Typedoc reference.

Examples

• help: Adds the --help/-h option and manages printing help messages when the option is present or a UsageError occurs. Included in the core package.
• logger: A simple logger that logs the result of each execution step. Included in the core package.
• command-menu: Prompts the user to select a subcommand when required.

Routing and Command Resolution

Default Commands Directory

If you don't explicitly provide a commands directory when calling the run function, the framework automatically attempts to locate the commands directory in two ways:

1. Current Working Directory: It first checks for a directory named "commands" directly in your current working directory. This is useful if you want to keep your "commands" directory at the root of your project.
2. Caller Directory: If no "commands" directory is found in the current working directory, the framework looks for a "commands" folder adjacent to the file that called the run function. This is helpful for scenarios where your CLI script lives in a specific directory within your project (e.g., "cli/bin.js") and the commands are kept in a sibling directory called "cli/commands".

Command File/Module Resolution Steps

1. Parse Command String:

• The command string is split into tokens separated by spaces.
• The first token is assumed to be the command name.

2. Find Command File:

• Clide-JS attempts to locate a file with the same name as the command in the specified commands directory.
• If the file exists, it imports the module and checks for a default export, which should be the CommandModule object.

3. Handle Non-existent Files:

• If the command file isn't found directly:
  • The provided path is checked to ensure it's a directory. If so, it treats it as a pass-through command for further resolution.
  • If not, It attempts to resolve a parameterized command file (e.g., [param].ts).

4. Handle Parameterized Commands:

• Parameterized commands use filenames like [param].ts or [...param].ts to capture arguments.
• The filename is parsed to identify the parameter name and spread operator (if present).
• It attempts to import the corresponding file and checks for a default export.
• For spread operator commands, all remaining tokens are passed as the parameter value.

5. Prepare Resolved Command:

Once a command file is found:

• All options up to the next command token are parsed and removed from the remaining command string.
• A resolveNext function is added if the command isn't the last one in the string for further resolution of subcommands.
• If the command won't be executed (e.g., isMiddleware is false), its handler is replaced with a pass-through function.

Key Points

• The resolution process is flexible, handling various command formats and directory structures.
• Detailed error messages guide users in case of resolution issues.

Examples

1. Basic Command:

mycli list

The framework searches for list.js in the commands directory. If found, it imports the module and executes its handler.

2. Pass-through Command:

mycli settings ...

The framework identifies settings as a directory, treats it as a pass-through command, and expects further command resolution within the settings directory.

4. Subcommand:

mycli users create

• Either users.js or a users directory is first resolved, then create is identified as a subcommand.
• The framework looks for create.js in the users directory.

3. Parameterized Command:

mycli deploy prod

• After resolving deploy, The framework searches for prod.ts in the deploy directory.
• If not found, the framework will look for a parameterized file name and finds [environment].ts.
• The module is imported and the environment is set to prod in the State.params.

Key Points

• Clide-JS prioritizes direct file name matching for each token, followed by parameterized file names.
• Plugin and initial command options are removed before further processing.
• Resolution continues within a directory matching the name of the previously resolved command.

This flexible approach allows for intuitive command structures and efficient execution, making it ideal for building versatile CLI applications.

Dynamic Option Handling

Clide-JS introduces a dynamic and user-centric approach to handling command options, distinguishing it from many other CLI frameworks. Instead of validating options before execution, Clide-JS's OptionsGetter allows command handlers to address missing or invalid options dynamically, enhancing the user experience and offering more flexibility:

• Lazy Evaluation: Options are not immediately validated upon command execution. Instead, they are evaluated dynamically when accessed by the command handler.
• User Prompts: If an option is required but not provided, Clide-JS can prompt the user for input, allowing for interactive CLI experiences. This eliminates the need for remembering all options beforehand and provides a more guided experience.
• Option Getters: Each option is represented by a getter function that dynamically retrieves its value. Getters can prompt users for missing values, validate input, and provide default values if needed.

Benefits

• Enhanced Flexibility: Allows command handlers to deal with options in a context-sensitive manner, enhancing the adaptability of commands.
• Improved User Experience: By deferring validation and potentially prompting for input, Clide-JS makes CLI tools more user-friendly and interactive.
• Robust Error Handling: Dynamic validation allows for more informative and contextual error messages, improving debugging and user guidance.

Usage in Commands

When creating commands, the OptionsGetter provides a straightforward and intuitive interface for accessing and handling options.

// Example usage in a command
  options: {
    n: {
      type: 'string',
      alias: ['name'],
    },
    a: {
      type: 'string',
      alias: ['alt-name'],
    }
  },
  handler: async ({ options, next }) => {

    // Getter functions
    const name = await options.n();
    const altName = await options.a();

    // Alias getter functions
    const name = await options.name();
    const altName = await options.altName();

    // Get function
    const { name, altName } = options.get(['name', 'alt-name']);

    // Direct values access
    const { name, altName } = options.values;
  },

CLI Examples

Visit the examples directory to see Clide-JS in action.

Reference

Clide-JS uses Typedoc to autogenerate detailed references for each major component of the framework. See the Typedoc reference for a full breakdown of Clide-JS's APIs.

Contributing

Clide-JS is a new framework still under development. Contributions are welcome! You can get a brief overview of the code base in /notes/source-code.md. If you're unsure where to start, or if a feature would be welcomed, open an issue and start a conversation.