Class Option

constructor

• new Option(flags: string, description?: string): Option

  Parameters

  • flags: string
  • Optionaldescription: string

  Returns Option

OptionalargChoices

OptionaldefaultValue

OptionaldefaultValueDescription

description

OptionalenvVar

flags

OptionalhelpGroupHeading

hidden

Optionallong

mandatory

negate

optional

OptionalparseArg

OptionalpresetArg

required

Optionalshort

variadic

argParser

• argParser<T>(fn: (value: string, previous: T) => T): this

  Set the custom handler for processing CLI option arguments into option values.

  Type Parameters

  • T

  Parameters

  • fn: (value: string, previous: T) => T

  Returns this

attributeName

• attributeName(): string

  Return option name, in a camelcase format that can be used as an object attribute key.

  Returns string

choices

• choices(values: readonly string[]): this

  Only allow option value to be one of choices.

  Parameters

  • values: readonly string[]

  Returns this

conflicts

• conflicts(names: string | string[]): this

  Add option name(s) that conflict with this option. An error will be displayed if conflicting options are found during parsing.

  Parameters

  • names: string | string[]

  Returns this

  Example

  new Option('--rgb').conflicts('cmyk');
  new Option('--js').conflicts(['ts', 'jsx']);
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default

• default(value: unknown, description?: string): this

  Set the default value, and optionally supply the description to be displayed in the help.

  Parameters

  • value: unknown
  • Optionaldescription: string

  Returns this

env

• env(name: string): this

  Set environment variable to check for option value.

  An environment variables is only used if when processed the current option value is undefined, or the source of the current value is 'default' or 'config' or 'env'.

  Parameters

  • name: string

  Returns this

helpGroup

• helpGroup(heading: string): this

  Set the help group heading.

  Parameters

  • heading: string

  Returns this

hideHelp

• hideHelp(hide?: boolean): this

  Hide option in help.

  Parameters

  • Optionalhide: boolean

  Returns this

implies

• implies(optionValues: OptionValues): this

  Specify implied option values for when this option is set and the implied options are not.

  The custom processing (parseArg) is not called on the implied values.

  Parameters

  • optionValues: OptionValues

  Returns this

  Example

  program
    .addOption(new Option('--log', 'write logging information to file'))
    .addOption(new Option('--trace', 'log extra details').implies({ log: 'trace.txt' }));
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isBoolean

• isBoolean(): boolean

  Return whether a boolean option.

  Options are one of boolean, negated, required argument, or optional argument.

  Returns boolean

makeOptionMandatory

• makeOptionMandatory(mandatory?: boolean): this

  Whether the option is mandatory and must have a value after parsing.

  Parameters

  • Optionalmandatory: boolean

  Returns this

name

• name(): string

  Return option name.

  Returns string

preset

• preset(arg: unknown): this

  Preset to use when option used without option-argument, especially optional but also boolean and negated. The custom processing (parseArg) is called.

  Parameters

  • arg: unknown

  Returns this

  Example

  new Option('--color').default('GREYSCALE').preset('RGB');
  new Option('--donate [amount]').preset('20').argParser(parseFloat);
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