npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

parse-my-command

v0.3.31

Published

Parse argv with Commander.js without executing the command

Downloads

232

Readme

Parse My Command

Parse argv with Commander.js without executing the command

Commander.js doesn't support parsing argv without executing the command. This module provides a workaround for that.

Installation

npm install --save parse-my-command

Usage

import { Command } from "commander";
import { partialParse } from "parse-my-command";

const rootCommand = new Command("root")
  .requiredOption("-a, --option-a <value>", "option a")
  .action(() => {
    throw new Error("This should never get called");
  });

const childCommand = rootCommand
  .command("child")
  .requiredOption("-b, --option-b <value>", "option b")
  .requiredOption("-c, --option-c <value>", "option c")
  .action(() => {
    throw new Error("This should never get called");
  });

const argv = ["node", "index.mjs", "-a", "value1", "child", "-b", "value2"];

const {
  matchedCommand,
  providedOptions,
  missingOptions,
  providedOptionsSources,
} = partialParse(rootCommand, argv);

console.log(matchedCommand.name()); // child
console.log(providedOptions.get(childCommand)); // { optionB: 'value2' }
console.log(missingOptions.get(childCommand)); // Set(1) { 'optionC' }
console.log(providedOptionsSources.get(childCommand)); // Map(1) { 'optionB' => 'cli' }

More examples can be found in the examples directory.

Error Handling

partialParse throws in the following cases:

  1. In all cases where your Command with the default exitCallback would throw an error (e.g. when displaying help)
  2. In all cases where your command would throw an error before an action is executed except for when a required Option (not to be confused with an Argument) is missing (missing options are returned in the result object instead).

How It Works and Limitations

This module works by creating a (best-effort) clone of the command and its subcommands, setting the actions to no-op functions, and then parsing the argv with the cloned instance. This approach might have some limitations:

  1. The implementation might break if Commander.js changes its internals
  2. Custom argument and option processors are assumed to be pure functions
  3. Hook listeners attached to the commands will be ignored
  4. Some edge cases might not be handled correctly (please feel free to open an issue/PR in case you find any)