Method handleOptionValue

lib/command.js:683–709

(val, invalidValueMessage, valueSource)

    // handler for cli and env supplied values
    const handleOptionValue = (val, invalidValueMessage, valueSource) => {
      // val is null for optional option used without an optional-argument.
      // val is undefined for boolean and negated option.
      if (val == null && option.presetArg !== undefined) {
        val = option.presetArg;
      }

      // custom processing
      const oldValue = this.getOptionValue(name);
      if (val !== null && option.parseArg) {
        val = this._callParseArg(option, val, oldValue, invalidValueMessage);
      } else if (val !== null && option.variadic) {
        val = option._collectValue(val, oldValue);
      }

      // Fill-in appropriate missing values. Long winded but easy to follow.
      if (val == null) {
        if (option.negate) {
          val = false;
        } else if (option.isBoolean() || option.optional) {
          val = true;
        } else {
          val = ''; // not normal, parseArg might have failed or be a mock function for testing
        }
      }
      this.setOptionValueWithSource(name, val, valueSource);
    };

    this.on('option:' + oname, (val) => {
      const invalidValueMessage = `error: option '${option.flags}' argument '${val}' is invalid.`;