sindresorhus

meow

Matches any [primitive value](https://developer.mozilla.org/en-US/docs/Glossary/Primitive).

This type can be useful to enforce some input to be JSON-compatible or as a super-type to be extended from. Don't use this as a direct return type as the user would have to double-cast it: `jsonObject as unknown as CustomResponse`. Instead, you could extend your CustomResponse type from it to ensure your type only uses JSON-compatible types: `interface CustomResponse extends JsonObject { … }`.

type JsonObject = {[Key in string]: JsonValue} & {[Key in string]?: JsonValue | undefined};

type JsonArray = JsonValue[] | readonly JsonValue[];

type JsonPrimitive = string | number | boolean | null;

@see `Jsonify` if you need to transform a type to one that is assignable to `JsonValue`.

type JsonValue = JsonPrimitive | JsonObject | JsonArray;

	// eslint-disable-next-line @typescript-eslint/consistent-type-definitions -- It has to be an `interface` so that it can be merged.

type TrimLeft<V extends string> = V extends `${Whitespace}${infer R}` ? TrimLeft<R> : V;

type TrimRight<V extends string> = V extends `${infer R}${Whitespace}` ? TrimRight<R> : V;

Remove leading and trailing spaces from a string.

type Trim<V extends string> = TrimLeft<TrimRight<V>>;

	The number of spaces to use for indenting the help text.

type PossiblyOptionalFlag<Flag extends AnyFlag, FlagType> =

type TypedFlags<Flags extends AnyFlags> = {

	[F in keyof Flags]: Flags[F] extends {isMultiple: true}

		? PossiblyOptionalFlag<Flags[F], Array<TypedFlag<Flags[F]>>>

		: PossiblyOptionalFlag<Flags[F], TypedFlag<Flags[F]>>

	Flags converted to camelCase excluding aliases.

	flags: CamelCasedProperties<TypedFlags<Flags>> & Record<string, unknown>;

	Flags converted camelCase including aliases.

	unnormalizedFlags: TypedFlags<Flags> & Record<string, unknown>;

	@param exitCode - The exit code to use. Default: `2`.

@param helpMessage - Shortcut for the `help` option.

declare function meow<Flags extends AnyFlags>(helpMessage: string, options?: Options<Flags>): Result<Flags>;

import { y as yargsParser, t as trimNewlines, r as redent, n as normalizePackageData, c as camelcaseKeys } from './dependencies.js';

import { buildOptions } from './options.js';

import { buildParserOptions } from './parser.js';

import { checkUnknownFlags, validate, checkMissingRequiredFlags } from './validate.js';

const buildResult = (options, parserOptions) => {

	const argv = yargsParser(options.argv, parserOptions);

		help = trimNewlines((options.help || '').replace(/\t+\n*$/, ''));

			help = redent(help, options.helpIndent);

	if (!description && description !== false) {

	description &&= help ? `\n  ${description}\n` : `\n${description}`;

	description &&= help ? redent(`\n${description}\n`, options.helpIndent) : `\n${description}`;

		process.exit(typeof code === 'number' ? code : 2);

		console.log(typeof options.version === 'string' ? options.version : package_.version);

	if (argv._.length === 0 && options.argv.length === 1) {

		if (argv.version === true && options.autoVersion) {

		} else if (argv.help === true && options.autoHelp) {

	const flags = camelcaseKeys(argv, {exclude: ['--', /^\w$/]});

	for (const flagValue of Object.values(options.flags)) {

		if (Array.isArray(flagValue.aliases)) {

			for (const alias of flagValue.aliases) {

	checkMissingRequiredFlags(options.flags, flags, input);

const meow = (helpText, options = {}) => {

	const parsedOptions = buildOptions(helpText, options);

	const parserOptions = buildParserOptions(parsedOptions);

	const result = buildResult(parsedOptions, parserOptions);

	process.title = result.pkg.bin ? Object.keys(result.pkg.bin).at(0) : result.pkg.name;

import { fileURLToPath } from 'node:url';

import { a as readPackageUpSync } from './dependencies.js';

import { joinFlagKeys, decamelizeFlagKey } from './utils.js';

				filter: ([flagKey]) => flagKey.includes('-') && flagKey !== '--',

				message: flagKeys => `Flag keys may not contain '-'. Invalid flags: ${joinFlagKeys(flagKeys, '')}`,

				filter: ([, flag]) => Object.hasOwn(flag, 'alias'),

				message: flagKeys => `The option \`alias\` has been renamed to \`shortFlag\`. The following flags need to be updated: ${joinFlagKeys(flagKeys)}`,

				filter: ([, flag]) => Object.hasOwn(flag, 'choices') && !Array.isArray(flag.choices),

				message: flagKeys => `The option \`choices\` must be an array. Invalid flags: ${joinFlagKeys(flagKeys)}`,

				filter: ([, flag]) => flag.type && Array.isArray(flag.choices) && flag.choices.some(choice => typeof choice !== flag.type),

					const flagKeysAndTypes = flagKeys.map(flagKey => `(\`${decamelizeFlagKey(flagKey)}\`, type: '${options.flags[flagKey].type}')`);

					return `Each value of the option \`choices\` must be of the same type as its flag. Invalid flags: ${flagKeysAndTypes.join(', ')}`;

				filter: ([, flag]) => flag.default && Array.isArray(flag.choices) && ![flag.default].flat().every(value => flag.choices.includes(value)),

				message: flagKeys => `Each value of the option \`default\` must exist within the option \`choices\`. Invalid flags: ${joinFlagKeys(flagKeys)}`,

	for (const [optionKey, filters] of Object.entries(invalidOptionFilters)) {

		const optionEntries = Object.entries(options[optionKey]);

		for (const {filter, message} of Object.values(filters)) {

			const invalidOptions = optionEntries.filter(option => filter(option));

			const invalidOptionKeys = invalidOptions.map(([key]) => key);

				errorMessages.push(message(invalidOptionKeys));

		throw new Error(errorMessages.join('\n'));

const buildOptions = (helpText, options) => {

		throw new TypeError('The `importMeta` option is required. Its value must be `import.meta`.');

	const foundPackage = readPackageUpSync({

		cwd: dirname(fileURLToPath(options.importMeta.url)),

		pkg: foundPackage ? foundPackage.packageJson : {},

	"funding": "https://github.com/sponsors/sindresorhus",

		"test": "xo && npm run build && ava && tsd --typings build/index.d.ts"

		"@rollup/plugin-node-resolve": "^15.2.3",

*I would recommend reading this [guide](https://clig.dev) on how to make user-friendly command-line tools.*

- Converts flags to [camelCase](https://github.com/sindresorhus/camelcase)

- Negates flags when using the `--no-` prefix

- Outputs description and supplied help text when `--help`

- Makes unhandled rejected promises [fail hard](https://github.com/sindresorhus/hard-rejection) instead of the default silent fail

- Sets the process title to the binary name defined in package.json

- `flags` *(Object)* - Flags converted to camelCase excluding aliases

- `unnormalizedFlags` *(Object)* - Flags converted to camelCase including aliases

- `pkg` *(Object)* - The `package.json` object

- `help` *(string)* - The help text used with `--help`

- `showHelp([exitCode=2])` *(Function)* - Show the help text and exit with `exitCode`

- `showVersion()` *(Function)* - Show the version text and exit

Pass in [`import.meta`](https://nodejs.org/dist/latest/docs/api/esm.html#esm_import_meta). This is used to find the correct package.json file.

The number of spaces to use for indenting the help text.

Meow will make unhandled rejected promises [fail hard](https://github.com/sindresorhus/hard-rejection) instead of the default silent fail. Meaning you don't have to manually `.catch()` promises used in your CLI.

See [`chalk`](https://github.com/chalk/chalk) if you want to colorize the terminal output.

See [`get-stdin`](https://github.com/sindresorhus/get-stdin) if you want to accept input from stdin.

See [`conf`](https://github.com/sindresorhus/conf) if you need to persist some data.

[More useful CLI utilities…](https://github.com/sindresorhus/awesome-nodejs#command-line-utilities)

		@@ -1315,2 +1315,9 @@ /**
		readonly allowUnknownFlags?: boolean;

		/**
		The number of spaces to use for indenting the help text.

		@default 2
		*/
		readonly helpIndent?: number;
		};
		@@ -1317,0 +1324,0 @@

		@@ -16,3 +16,3 @@ import process from 'node:process';
		if (help.includes('\n')) {
		help = redent(help, 2);
		help = redent(help, options.helpIndent);
		}
		@@ -30,3 +30,3 @@

		description &&= help ? `\n ${description}\n` : `\n${description}`;
		description &&= help ? redent(`\n${description}\n`, options.helpIndent) : `\n${description}`;
		help = `${description \|\| ''}${help}\n`;
		@@ -33,0 +33,0 @@

		@@ -83,2 +83,3 @@ import process from 'node:process';
		allowParentFlags: true,
		helpIndent: 2,
		...options,
		@@ -85,0 +86,0 @@ };

		{
		"name": "meow",
		"version": "13.1.0",
		"version": "13.2.0",
		"description": "CLI app helper",
		@@ -5,0 +5,0 @@ "license": "MIT",

		@@ -295,2 +295,9 @@ # meow

		##### helpIndent

		Type `number`\
		Default: `2`

		The number of spaces to use for indenting the help text.

		## Promises
		@@ -297,0 +304,0 @@

Improved metrics