argparse-ts
Version:
Modern CLI arguments parser for node.js
167 lines • 5.41 kB
JavaScript
/**
* Parses an array of command-line arguments into positional and optional arguments.
*
* @param argv - The array of command-line arguments.
* @returns A tuple containing an array of positional arguments and a record of optional arguments.
*
* @category Utils
*
* @example
* ```
* const argv = ['make', '--flag', '-v', 'a', 'b', 'c'];
* const [positional, optional] = parseArgsArray(argv);
* console.log(positional); // ['make']
* console.log(optional); // { '--flag': [], '-v': ['a', 'b', 'c'] }
* ```
*/
export function parseArgsArray(argv) {
// Find the index of the first argument that starts with a dash.
const foundIndex = argv.findIndex((x) => isOptionalArgGiven(x));
// If no such argument is found, set the index to the length of the array.
const optionalBegin = foundIndex !== -1 ? foundIndex : argv.length;
// The positional arguments are the arguments that come before the first option.
const positional = [...argv.slice(0, optionalBegin)];
// Build the buffer of optional arguments.
const optionalBuffer = [...argv.slice(optionalBegin)].reverse();
// Store the parsed optional arguments in this record.
const optional = {};
// The current argument name and values.
let argName = undefined;
let argValues = [];
// Iterate over the buffer of optional arguments.
while (optionalBuffer.length > 0) {
const item = optionalBuffer.pop();
// If the item includes glued together aliases, expand it.
if (item.match(/^-[a-zA-Z]{2,}$/)) {
// Split the alias into individual characters and reverse the order.
const items = item.slice(1).split('').reverse();
// Add the expanded alias arguments to the buffer.
optionalBuffer.push(...items.map((x) => `-${x}`));
continue;
}
// If the item is a new argument, store the previous argument if it exists.
if (isOptionalArgGiven(item)) {
if (argName !== undefined) {
// Store the previous argument.
optional[argName] = argValues;
}
// The current argument name is the item.
argName = item;
// Reset the current argument values.
argValues = [];
}
else {
// If the item is a value of the current argument, add it to the values.
argValues.push(item);
}
}
// Store the last argument.
if (argName !== undefined) {
optional[argName] = argValues;
}
return [positional, optional];
}
/**
* Formats the argument name with alias.
*
* @param argConfig - The argument configuration.
*
* @returns The formatted argument name.
*
* @category Utils
*/
export function formatArgNameWithAlias(argConfig) {
return `${argConfig.name}${argConfig.alias ? ` (${argConfig.alias})` : ''}`;
}
/**
* Builds the extra configuration for an argument.
*
* @param config - The argument configuration.
*
* @returns The extra configuration.
*
* @category Utils
*/
export function buildArgExtraConfig(config) {
const positional = isArgPositional(config);
const multiple = isArgMultiple(config);
const required = isArgRequired(config);
const allowEmpty = isArgAllowEmpty(config);
const valuesCount = typeof config.nargs === 'number' ? config.nargs : undefined;
const minValuesCount = valuesCount !== null && valuesCount !== void 0 ? valuesCount : (allowEmpty ? 0 : 1);
return { positional, multiple, required, allowEmpty, valuesCount, minValuesCount };
}
/**
* Determines if the argument is positional.
*
* @param config - The argument configuration.
*
* @returns True if the argument is positional, otherwise false.
*
* @category Utils
*/
function isArgPositional(config) {
return !config.name.startsWith('--');
}
/**
* Determines if the argument can accept multiple values.
*
* @param config - The argument configuration.
*
* @returns True if the argument can accept multiple values, otherwise false.
*
* @category Utils
*/
function isArgMultiple(config) {
return config.nargs === '*'
|| config.nargs === '+'
|| typeof config.nargs === 'number';
}
/**
* Determines if the argument is required.
*
* @param config - The argument configuration.
*
* @returns True if the argument is required, otherwise false.
*
* @category Utils
*/
function isArgRequired(config) {
if (config.required) {
return true;
}
if (!isArgPositional(config) && config.nargs === undefined) {
return false;
}
return config.nargs !== '*'
&& config.nargs !== '?'
&& config.default === undefined;
}
/**
* Determines if the argument allows an empty value.
*
* @param config - The argument configuration.
*
* @returns True if the argument allows an empty value, otherwise false.
*
* @category Utils
*/
function isArgAllowEmpty(config) {
return config.nargs === '*'
|| config.nargs === '?'
|| config.const !== undefined
|| (isArgPositional(config) && !isArgRequired(config));
}
/**
* Determines if the argument is optional.
*
* @param argName - The argument name.
*
* @returns True if the argument is optional, otherwise false.
*
* @category Utils
*/
function isOptionalArgGiven(argName) {
return argName.startsWith('-') && isNaN(Number(argName));
}
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