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promptly

promptly

NPM version Downloads Build Status Coverage Status Dependency status Dev Dependency status Greenkeeper badge

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 = await 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 = await 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 = await promptly.password('Type a password: ');
     
    console.log('Password:', password);
  • Ask for a password but mask the input with *:

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

License

Released under the MIT License.