Inquirer.js is a collection of common interactive command-line user interfaces. This includes typing answers to questions or selecting a choice from a list.
The inquirer
package provides several default prompts and is highly configurable. It is also extensible by way of a plug-in interface. It even supports promises and async/await
syntax.
In this article, you will install and explore some of the features of Inquirer.js.
If you would like to follow along with this article, you will need:
This tutorial was verified with Node v15.14.0, npm
v7.10.0, and inquirer
v8.0.0.
First, open your terminal window and create a new project directory:
mkdir inquirer-example
Then, navigate to this directory:
cd inquirer-example
To start adding prompts to your Node.js scripts, you will need to install the inquirer
package:
- npm install inquirer
At this point, you have a new project ready to use Inquirer.js.
Now, create a new index.js
file in your project directory and open it with your code editor.
Within your script, be sure to require inquirer
:
const inquirer = require('inquirer');
Add a prompt asking the user for their favorite reptile:
const inquirer = require('inquirer');
inquirer
.prompt([
{
name: 'faveReptile',
message: 'What is your favorite reptile?'
},
])
.then(answers => {
console.info('Answer:', answers.faveReptile);
});
Revisit your terminal window and run the script:
- node index.js
You will be presented with a prompt:
Output? What is your favorite reptile?
Providing an answer will display the response:
Output? What is your favorite reptile? Crocodiles
Answer: Crocodiles
You can provide a default
value that allows the user to press ENTER
without submitting any answer:
const inquirer = require('inquirer');
inquirer
.prompt([
{
name: 'faveReptile',
message: 'What is your favorite reptile?',
default: 'Alligators'
},
])
.then(answers => {
console.info('Answer:', answers.faveReptile);
});
Run the script again, and you will be presented with a prompt:
Output? What is your favorite reptile? (Alligators)
Pressing ENTER
without an answer will submit the default answer:
Output? What is your favorite reptile? Alligators
Answer: Alligators
Now, you can create prompts and set default values.
You may have noticed the .prompt()
method accepts an array or objects. That’s because you can string a series of prompt questions together and all of the answers will be available by name as part of the answers
variable once all of the prompts have been resolved.
Revisit index.js
in your code editor and add a prompt asking the user for their favorite color:
const inquirer = require('inquirer');
inquirer
.prompt([
{
name: 'faveReptile',
message: 'What is your favorite reptile?',
default: 'Alligators'
},
{
name: 'faveColor',
message: 'What is your favorite color?',
default: '#008f68'
},
])
.then(answers => {
console.info('Answers:', answers);
});
Run the script again, and you will be presented with two prompts:
Output? What is your favorite reptile? Alligators
? What is your favorite color? #008f68
Answers: { faveReptile: 'Alligators', faveColor: '#008f68' }
Now, you can create multiple prompts.
inquirer
does support more than prompting a user for text input. For the sake of example, the following types will be showcased by themselves but you very well could chain them together by passing them in the same array.
The list
type allows you to present the user with a fixed set of options to pick from, instead of a free form input as the input
type provides:
const inquirer = require('inquirer');
inquirer
.prompt([
{
type: 'list',
name: 'reptile',
message: 'Which is better?',
choices: ['alligator', 'crocodile'],
},
])
.then(answers => {
console.info('Answer:', answers.reptile);
});
Revisit your terminal window and run the script:
- node list.js
You will be presented with a list
prompt:
Output? Which is better? (Use arrow keys)
❯ alligator
crocodile
The user can ARROW UP
and ARROW DOWN
keys to navigate the list of choices. j
and k
keyboard navigation is also available.
The rawlist
type is similar to list
. It displays a list of choices and allows the user to enter the index of their choice (starting at 1
):
const inquirer = require('inquirer');
inquirer
.prompt([
{
type: 'rawlist',
name: 'reptile',
message: 'Which is better?',
choices: ['alligator', 'crocodile'],
},
])
.then(answers => {
console.info('Answer:', answers.reptile);
});
Revisit your terminal window and run the script:
- node list.js
You will be presented with a rawlist
prompt:
Output? Which is better?
1) alligator
2) crocodile
Answer:
Submitting an invalid value will result in a "Please enter a valid index"
error.
The expand
type is reminiscent of some command-line applications that present you with a list of characters that map to functionality that can be entered. expand
prompts will initially present the user with a list of the available character values and give context to them when the key is pressed:
const inquirer = require('inquirer');
inquirer
.prompt([
{
type: 'expand',
name: 'reptile',
message: 'Which is better?',
choices: [
{
key: 'a',
value: 'alligator',
},
{
key: 'c',
value: 'crocodile',
},
],
},
])
.then(answers => {
console.info('Answer:', answers.reptile);
});
Revisit your terminal window and run the script:
- node expand.js
You will be presented with a expand
prompt:
Output? Which is better? (acH)
By default, the H
option is included which stands for "Help"
and upon entering H
and hitting ENTER
will switch to a list of the options, indexed by their characters that can then be entered to make a selection.
Output? Which is better? (acH)
a) alligator
c) crocodile
h) Help, list all options
Answer:
Submitting an invalid value will result in a "Please enter a valid command"
error.
The checkbox
type is also similar to list
. Instead of a single selection, it allows you to select multiple choices.
const inquirer = require('inquirer');
inquirer
.prompt([
{
type: 'checkbox',
name: 'reptiles',
message: 'Which reptiles do you love?',
choices: [
'Alligators', 'Snakes', 'Turtles', 'Lizards',
],
},
])
.then(answers => {
console.info('Answer:', answers.reptiles);
});
Revisit your terminal window and run the script:
- node checkbox.js
You will be presented with a checkbox
prompt:
Output? Which reptiles do you love? (Press <space> to select, <a> to toggle all, <i> to invert selection)
❯◯ Alligators
◯ Snakes
◯ Turtles
◯ Lizards
Similar to the other list
types, you can use the arrow keys to navigate. To make a selection, you hit SPACE
and can also select all with a
or invert your selection with i
.
OutputAnswer: [ 'Alligators', 'Snakes', 'Turtles', 'Lizards' ]
Unlike the other prompt types, the answer for this prompt type will return an array instead of a string. It will always return an array, even if the user opted to not select any items.
The password
type will hide input from the user. This allows users to provide sensitive information that should not be seen:
const inquirer = require('inquirer');
inquirer
.prompt([
{
type: 'password',
name: 'secret',
message: 'Tell me a secret',
},
])
.then(answers => {
// Displaying the password for debug purposes only.
console.info('Answer:', answers.secret);
});
Revisit your terminal window and run the script:
- node password.js
You will be presented with a password
prompt:
Output? Tell me a secret [hidden]
The input is hidden from the user.
The editor
type allows users to use their default text editor for larger text inputs.
const inquirer = require('inquirer');
inquirer
.prompt([
{
type: 'editor',
name: 'story',
message: 'Tell me a story, a really long one!',
},
])
.then(answers => {
console.info('Answer:', answers.story);
});
Revisit your terminal window and run the script:
- node editor.js
You will be presented with an editor
prompt:
Output? Tell me a story, a really long one! Press <enter> to launch your preferred editor.
inquirer
will attempt to open a text editor on the user’s system based on the value of the $EDITOR
and $VISUAL
environment variables. If neither are present, vim
(Linux) and notepad.exe
(Windows) will be used instead.
In this article, you installed and explored some of the features of Inquirer.js. This tool can be useful for retrieving information from users.
Continue your learning with some of the plugins. Like inquirer-autocomplete-prompt
, inquirer-search-list
, and inquirer-table-prompt
.
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Thanks for the awesome post. Thank you