@jil/args/src/errors.ts

A convention based argument parsing and formatting library, with strict validation checks

import {createScopedError} from '@jil/common/errors/scoped';

const errors = {
  COMMAND_INVALID_FORMAT: 'Invalid "{0}" command format. Must be letters, numbers, and dashes.',
  COMMAND_NOT_FIRST: 'Command must be passed as the first non-option, non-param argument.',
  COMMAND_PROVIDED: 'Command has already been provided as "{0}", received another "{1}".',
  CONTEXT_REQUIRED: 'Contextual parser options were not provided.',
  GROUP_REQUIRED_COUNT: 'Numeric options must have `count` enabled when passed in a short option group.',
  GROUP_UNSUPPORTED_TYPE: 'Only boolean and countable number options may be used in a short option group.',
  OPTION_INVALID_COUNT_TYPE: 'Only numeric options may use the `count` setting.',
  OPTION_UNKNOWN: 'Unknown option "{0}" found.',
  OPTION_UNKNOWN_FORMAT: 'Unknown option format.',
  OPTION_UNKNOWN_MORE: 'Unknown option "{0}" found. Did you mean "{1}"?',
  PARAM_INVALID_ORDER: 'Optional param(s) {0} found before required param "{1}". Required must be first.',
  PARAM_REQUIRED: 'Param "{0}" is required but value is undefined.',
  PARAM_REQUIRED_NO_DEFAULT: 'Required param "{0}" has a default value, which is not allowed.',
  PARAM_UNKNOWN: 'Unknown param "{0}" found. Variadic params are not supported.',
  SHORT_DEFINED: 'Short option "{0}" has already been defined for "{1}".',
  SHORT_INVALID_CHAR: 'Short option "{0}" may only be a single letter.',
  SHORT_UNKNOWN: 'Unknown short option "{0}". No associated long option found.',
  VALUE_INVALID_ARITY: 'Not enough arity arguments. Require {0}, found {1}.',
  VALUE_INVALID_CHOICE: 'Invalid value, must be one of {0}, found {1}.',
  VALUE_INVALID_FORMAT: 'Value was formatted to an invalid type. Expected {0}, found {1}.',
  VALUE_NO_INLINE: 'Flags and short option groups may not use inline values.',
  VALUE_NON_ARRAY: 'Option "{0}" is enabled for multiple values, but non-array default value found.',
  VALUE_NON_BOOL: 'Option "{0}" is set to boolean, but non-boolean default value found.',
  VALUE_NON_NUMBER: 'Option "{0}" is set to number, but non-number default value found.',
  VALUE_NON_STRING: 'Option "{0}" is set to string, but non-string default value found.',
};

export type ArgsErrorCode = keyof typeof errors;

export const ArgsError = createScopedError<ArgsErrorCode>('ARG', 'ArgsError', errors);

export class ParseError extends Error {
  arg: string;

  index: number;

  constructor(message: string, arg: string, index: number) {
    super(message);

    this.name = 'ParseError';
    this.arg = arg;
    this.index = index;
  }
}