cli-script-utils

This repository contains some of the utility functions that I've used for almost any cli script that I've written. The focus has been on simplicity and brevity.

These functions have by no means been completely tested, or are overly-powerful or configurable. However, they have no external and very few interal dependencies so that inlining (copy-pasting) into scripts is easy.

Functions

glob(dir: string, pattern: string): string[]

A simple glob implementation.

compileGlobPattern(pattern: string): RegExp

Compiles a given glob pattern to a RegExp.
WARNING: Not a standards compliant implementation.

compileGlobPredicate(globs: string[]): (x: string) => boolean

Compiles a the given glob patterns to a predicate function. Globs are devided into positive and neative ones (i.e. starting with !). The compiled predicate returns true if its argument matches any of the positive globs and none of the negative ones.

const predicate = compileGlobPredicate([
    '**/*.js',
    '!built/**/*'
]);

predicate('hello.js'); // true
predicate('built/hello.js'); // false

readdirr(path: string): string[]

A recursive synchronous version of readdir. Useful for reading the contents of a directory which may contain other nested directories. Doesn't throw if the specified path doesn't exist or leads to a file.

rmrf(path: string): void

A recursive synchronous version of rm. Useful for deleting directories which may contain other nested directories. Doesn't throw if the specified path doesn't exist.

mkdirr(path: string): void

A recursive synchronous version of mkdir. Useful when creating nested directories.

exists(path: string): boolean

An alias for fs.existsSync.

readFile(path: string): string

Synchronously reads the file at the specified path and returns its content as a UTF-8 encoded string.

writeFile(path: string, content: string): void

Synchronously writes a file at the specified path with the provided content.

unixPath(path: string): string

Given a path that contains forward and/or backward slashes, returns a path with forward slashes only.

fetch(url: string): Promise<string>

Makes an HTTPS GET request and returns the content of the response. Redirects are followed. Currently only GET is supported.

getFlagOption(option: string): boolean

Checks argv and returns whether such an option has been provided.

// argv: [ 'node', 'myscript.js', '--verbose' ]
getFlagOption('--verbose'); // true
getFlagOption('--version'); // false

getValueOption(option: string): string

Retrieves the value provided to option as string.

// argv: [ 'node', 'myscript.js', '--path=built/main.js', '--positioned', 'next-pos' ]
getValueOption('--path'); // 'built/main.js'
getValueOption('--positioned'); // 'next-pos'

match(text: string, rx: RegExp): string[][]

Executes the RegExp rx on text and returns the results of all matches.

trai<T>(f: () => T, def: T): T

An expression varion of try. Executes the provided thunk f and returns its result. In case of an error, returns the default value def.

exit(code: number): never

An alias for process.exit.

fail(msg?: string, marker?: Function): never

An expression version of throw. Throws an Error with the provided message.
NOTE: If a marker function is provided and the host environment allows stack trace manipulation, all frames following and including marker will be omitted.

die(msg: string): never

Akin to fail but calls process.exit(1) instead of throwing an exception. The message is logged on stderr.