@jil/args/src/Scope.ts

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

import {LongOptionName, OptionConfig, ValueType} from './types';
import {castValue} from './utils/castValue';
import {formatValue} from './utils/formatValue';

export class Scope {
  config: OptionConfig;

  name: LongOptionName;

  negated = false;

  unknown = false;

  value?: string[] | string;

  constructor(name: LongOptionName, config?: OptionConfig) {
    this.name = name;

    if (config) {
      this.config = config;
    } else {
      this.config = {description: '', type: 'string'};
      this.unknown = true;
    }
  }

  get flag(): boolean {
    return this.config.type === 'boolean';
  }

  get finalValue(): ValueType {
    return formatValue(castValue(this.value, this.config.type), this.config.format);
  }

  captureValue(value: string, commit: () => void) {
    const {config} = this;

    // Update the scope with this new value
    if (config.multiple) {
      (this.value as string[]).push(value);
    } else {
      this.value = value;
    }

    // Commit scope when a single value is set,
    // or when a multiple arity is met.
    if (!config.multiple || (config.arity && Array.isArray(this.value) && this.value.length >= config.arity)) {
      commit();
    }
  }
}