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const flagSymbol = Symbol('arg flag'); |
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|
|
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|
function arg(opts, {argv = process.argv.slice(2), permissive = false, stopAtPositional = false} = {}) { |
|
|
if (!opts) { |
|
|
throw new Error('Argument specification object is required'); |
|
|
} |
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|
|
|
|
const result = {_: []}; |
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|
|
|
|
const aliases = {}; |
|
|
const handlers = {}; |
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|
|
|
|
for (const key of Object.keys(opts)) { |
|
|
if (!key) { |
|
|
throw new TypeError('Argument key cannot be an empty string'); |
|
|
} |
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|
|
|
|
if (key[0] !== '-') { |
|
|
throw new TypeError(`Argument key must start with '-' but found: '${key}'`); |
|
|
} |
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|
|
|
|
if (key.length === 1) { |
|
|
throw new TypeError(`Argument key must have a name; singular '-' keys are not allowed: ${key}`); |
|
|
} |
|
|
|
|
|
if (typeof opts[key] === 'string') { |
|
|
aliases[key] = opts[key]; |
|
|
continue; |
|
|
} |
|
|
|
|
|
let type = opts[key]; |
|
|
let isFlag = false; |
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|
|
|
|
if (Array.isArray(type) && type.length === 1 && typeof type[0] === 'function') { |
|
|
const [fn] = type; |
|
|
type = (value, name, prev = []) => { |
|
|
prev.push(fn(value, name, prev[prev.length - 1])); |
|
|
return prev; |
|
|
}; |
|
|
isFlag = fn === Boolean || fn[flagSymbol] === true; |
|
|
} else if (typeof type === 'function') { |
|
|
isFlag = type === Boolean || type[flagSymbol] === true; |
|
|
} else { |
|
|
throw new TypeError(`Type missing or not a function or valid array type: ${key}`); |
|
|
} |
|
|
|
|
|
if (key[1] !== '-' && key.length > 2) { |
|
|
throw new TypeError(`Short argument keys (with a single hyphen) must have only one character: ${key}`); |
|
|
} |
|
|
|
|
|
handlers[key] = [type, isFlag]; |
|
|
} |
|
|
|
|
|
for (let i = 0, len = argv.length; i < len; i++) { |
|
|
const wholeArg = argv[i]; |
|
|
|
|
|
if (stopAtPositional && result._.length > 0) { |
|
|
result._ = result._.concat(argv.slice(i)); |
|
|
break; |
|
|
} |
|
|
|
|
|
if (wholeArg === '--') { |
|
|
result._ = result._.concat(argv.slice(i + 1)); |
|
|
break; |
|
|
} |
|
|
|
|
|
if (wholeArg.length > 1 && wholeArg[0] === '-') { |
|
|
|
|
|
const separatedArguments = (wholeArg[1] === '-' || wholeArg.length === 2) |
|
|
? [wholeArg] |
|
|
: wholeArg.slice(1).split('').map(a => `-${a}`); |
|
|
|
|
|
|
|
|
for (let j = 0; j < separatedArguments.length; j++) { |
|
|
const arg = separatedArguments[j]; |
|
|
const [originalArgName, argStr] = arg[1] === '-' ? arg.split(/=(.*)/, 2) : [arg, undefined]; |
|
|
|
|
|
let argName = originalArgName; |
|
|
while (argName in aliases) { |
|
|
argName = aliases[argName]; |
|
|
} |
|
|
|
|
|
if (!(argName in handlers)) { |
|
|
if (permissive) { |
|
|
result._.push(arg); |
|
|
continue; |
|
|
} else { |
|
|
const err = new Error(`Unknown or unexpected option: ${originalArgName}`); |
|
|
err.code = 'ARG_UNKNOWN_OPTION'; |
|
|
throw err; |
|
|
} |
|
|
} |
|
|
|
|
|
const [type, isFlag] = handlers[argName]; |
|
|
|
|
|
if (!isFlag && ((j + 1) < separatedArguments.length)) { |
|
|
throw new TypeError(`Option requires argument (but was followed by another short argument): ${originalArgName}`); |
|
|
} |
|
|
|
|
|
if (isFlag) { |
|
|
result[argName] = type(true, argName, result[argName]); |
|
|
} else if (argStr === undefined) { |
|
|
if ( |
|
|
argv.length < i + 2 || |
|
|
( |
|
|
argv[i + 1].length > 1 && |
|
|
(argv[i + 1][0] === '-') && |
|
|
!( |
|
|
argv[i + 1].match(/^-?\d*(\.(?=\d))?\d*$/) && |
|
|
( |
|
|
type === Number || |
|
|
|
|
|
(typeof BigInt !== 'undefined' && type === BigInt) |
|
|
) |
|
|
) |
|
|
) |
|
|
) { |
|
|
const extended = originalArgName === argName ? '' : ` (alias for ${argName})`; |
|
|
throw new Error(`Option requires argument: ${originalArgName}${extended}`); |
|
|
} |
|
|
|
|
|
result[argName] = type(argv[i + 1], argName, result[argName]); |
|
|
++i; |
|
|
} else { |
|
|
result[argName] = type(argStr, argName, result[argName]); |
|
|
} |
|
|
} |
|
|
} else { |
|
|
result._.push(wholeArg); |
|
|
} |
|
|
} |
|
|
|
|
|
return result; |
|
|
} |
|
|
|
|
|
arg.flag = fn => { |
|
|
fn[flagSymbol] = true; |
|
|
return fn; |
|
|
}; |
|
|
|
|
|
|
|
|
arg.COUNT = arg.flag((v, name, existingCount) => (existingCount || 0) + 1); |
|
|
|
|
|
module.exports = arg; |
|
|
|