ex-scripts of npm scripts

cli.js

#!/usr/bin/env node

const fs = require("fs")
const path = require("path")

const findPackageJson = () => {
	let dir = process.cwd()

	while (true) {
		const json_path = path.join(dir, "package.json")
		if (fs.existsSync(json_path)) {
			return require(json_path)
		}

		const parent = path.dirname(dir)
		if (dir === parent) return null
		dir = parent
	}
}

const [name, ...raw_params] = process.argv.slice(2)

if (!name) {
	console.error("Script name is required.")
	console.error("Usage: exsc <name> <param1> <param2> ...")
	process.exit(1)
}

const pkg = findPackageJson()
if (!pkg || !pkg.exsc || !pkg.exsc[name]) {
	console.error(`"${name}" is not found in package.json.`)
	process.exit(1)
}

const opt = pkg.exsc[name]
const { command, defaults } = typeof opt === "string" ? { command: opt } : opt
if (!command) {
	console.error(`"command" property is required.`)
	process.exit(1)
}

const { result: parsed_params } = raw_params.reduce(
	(acc, value) => {
		if (value.startsWith("-")) {
			acc.ctx = value.replace(/^-+/g, "")
		} else {
			acc.result[acc.ctx || acc.index++] = value
			acc.ctx = null
		}
		return acc
	},
	{
		index: 1,
		ctx: null,
		result: {},
	}
)

const comm = String(command).replace(/\{([a-zA-Z0-9_]+)\}/g, (_, p) => {
	if (p in parsed_params) return parsed_params[p]
	if (defaults && p in defaults) return defaults[p]
	console.error(`"${p}" is not found in params and defaults.`)
	process.exit(1)
})

require("child_process").spawnSync(comm, { shell: true, stdio: "inherit" })

package.json

{
  "name": "exsc",
  "version": "1.0.0",
  "bin": "cli.js"
}