promptly

Simple command line prompting utility.

Installation

$ npm install promptly

API

.prompt(message, [options])

Prompts for a value, printing the message and waiting for the input.
Returns a promise that resolves with the input.

Available options:

Name	Description	Type	Default
default	The default value to use if the user provided an empty input	string	undefined
trim	Trims the user input	boolean	true
validator	A validator or an array of validators	Function/Array	undefined
retry	Retry if any of the validators fail	boolean	true
silent	Do not print what the user types	boolean	false
replace	Replace each character with the specified string when silent is true	string	''
input	Input stream to read from	Stream	process.stdin
output	Output stream to write to	Stream	process.stdout

The same options are available to all functions but with different default values.

Examples

• Ask for a name:

  const name = await promptly.prompt('Name: ');
  
  console.log(name);

• Ask for a name with a constraint (non-empty value and length > 2):

  const validator = function (value) {
      if (value.length < 2) {
          throw new Error('Min length of 2');
      }
  
      return value;
  };
  
  const name = await promptly.prompt('Name: ', { validator });
  
  // Since retry is true by default, promptly will keep asking for a name until it is valid
  // Between each prompt, the error message from the validator will be printed
  console.log('Name is:', value);

• Same as above but do not retry automatically:

  var validator = function (value) {
      if (value.length < 2) {
          throw new Error('Min length of 2');
      }
  
      return value;
  };
  
  try {
      const name = promptly.prompt('Name: ', { validator, retry: false });
  
      console.log('Name is:', value);
  } catch (err) {
      console.error('Invalid name:')
      console.error(`- ${err.message}`);
  }

Validators

The validators have two purposes: to validate and to transform input.

(value) => {
    // Validation example, throwing an error when invalid
    if (value.length !== 2) {
        throw new Error('Length must be 2');
    }

    // Parse the value, modifying it
    return value.replace('aa', 'bb');
}

.confirm(message, [options])

Ask the user for confirmation, printing the message and waiting for the input. Returns a promise that resolves with the answer.

Truthy values are: y, yes and 1. Falsy values are n, no, and 0.
Comparison is made in a case insensitive way.

The same options from prompt are available.

Examples

• Ask to confirm something important:

  const answer = await promptly.confirm('Are you really sure? ');
  
  console.log('Answer:', answer);

.choose(message, choices, [options])

Ask the user to choose between multiple choices (array of choices), printing the message and waiting for the input.
Returns a promise that resolves with the choice.

The same options from prompt are available.

Examples

• Ask to choose between:

  const choice = promptly.choose('Do you want an apple or an orange? ', ['apple', 'orange']);
  
  console.log('Choice:', choice);

.password(message, [options])

Prompts for a password, printing the message and waiting for the input.
Returns a promise that resolves with the password.

The same options from prompt are available, except that trim and silent default to false and default is an empty string to allow empty passwords.

Examples

• Ask for a password:

  const password = promptly.password('Type a password: ');
  
  console.log('Password:', password);

• Ask for a password but mask the input with *:

  const password = promptly.password('Type a password: ', { replace: '*' });
  
  console.log('Password:', password);

License

Released under the MIT License.