dedent

What is dedent?

The dedent npm package is a utility for stripping indentation from multi-line strings. It is commonly used to make template literals more readable by removing the leading whitespace that is introduced by indenting the code for readability purposes.

What are dedent's main functionalities?

Remove indentation from multi-line strings

This feature allows you to write multi-line strings in your code with indentation for readability, and then process them with dedent to remove the extra leading whitespace.

const dedent = require('dedent');

const text = dedent`
    Line one
    Line two
    Line three
`;
console.log(text); // 'Line one\nLine two\nLine three'

Other packages similar to dedent

strip-indent

The strip-indent package is similar to dedent in that it removes the leading indentation from every line in a string. The main difference is in the API and the way you use the package. While dedent is used as a tagged template literal, strip-indent is a function that takes a string as an argument.

outdent

Outdent is another package that offers similar functionality to dedent. It can be used both as a tagged template literal and as a function. It also provides additional features like the ability to maintain the relative indentation of lines within the block.

heredoc

Heredoc is a package that allows you to create multi-line strings without the first and last lines of padding. It's similar to dedent but focuses on the heredoc syntax known from other programming languages and does not specifically target the removal of indentation.

README

dedent

A string tag that strips indentation from multi-line strings. ⬅️

Usage

npm i dedent

import dedent from "dedent";

function usageExample() {
	const first = dedent`A string that gets so long you need to break it over
                       multiple lines. Luckily dedent is here to keep it
                       readable without lots of spaces ending up in the string
                       itself.`;

	const second = dedent`
    Leading and trailing lines will be trimmed, so you can write something like
    this and have it work as you expect:

      * how convenient it is
      * that I can use an indented list
         - and still have it do the right thing

    That's all.
  `;

	const third = dedent(`
    Wait! I lied. Dedent can also be used as a function.
  `);

	return first + "\n\n" + second + "\n\n" + third;
}

console.log(usageExample());

A string that gets so long you need to break it over
multiple lines. Luckily dedent is here to keep it
readable without lots of spaces ending up in the string
itself.

Leading and trailing lines will be trimmed, so you can write something like
this and have it work as you expect:

  * how convenient it is
  * that I can use an indented list
    - and still have it do the right thing

That's all.

Wait! I lied. Dedent can also be used as a function.

Options

You can customize the options dedent runs with by calling its withOptions method with an object:

import dedent from 'dedent';

dedent.withOptions({ /* ... */ })`input`;
dedent.withOptions({ /* ... */ })(`input`);

options returns a new dedent function, so if you'd like to reuse the same options, you can create a dedicated dedent function:

import dedent from 'dedent';

const dedenter = dedent.withOptions({ /* ... */ });

dedenter`input`;
dedenter(`input`);

escapeSpecialCharacters

JavaScript string tags by default add an extra \ escape in front of some special characters such as $ dollar signs. dedent will escape those special characters when called as a string tag.

If you'd like to change the behavior, an escapeSpecialCharacters option is available. It defaults to:

• false: when dedent is called as a function
• true: when dedent is called as a string tag

import dedent from "dedent";

// "$hello!"
dedent`
  $hello!
`;

// "\$hello!"
dedent.withOptions({ escapeSpecialCharacters: false })`
  $hello!
`;

// "$hello!"
dedent.withOptions({ escapeSpecialCharacters: true })`
  $hello!
`;

For more context, see 🚀 Feature: Add an option to disable special character escaping.

trimWhitespace

By default, dedent will trim leading and trailing whitespace from the overall string.

This can be disabled by setting trimWhitespace: false.

import dedent from "dedent";

// "hello!"
dedent`
  hello! 
`;

// "\nhello! \n"
dedent.withOptions({ trimWhitespace: false })`
  hello! 
`;

// "hello!"
dedent.withOptions({ trimWhitespace: true })`
  hello! 
`;

License

MIT

Contributors

Adrian Jost 💻	Andri Möll 🐛	Benny Powers - עם ישראל חי! 🔧	Craig Spence 💻	Desmond Brand 🐛 💻 📖 🤔 🚇 🚧 📆 🔧	Gareth Jones 💻 🐛	Gray Zhang 🐛
Haroen Viaene 💻 🚧	Hyeseong Kim 🔧 🚇	John L. Armstrong IV 🐛	Josh Goldberg ✨ 🐛 💻 📖 🤔 🚇 🚧 📆 🔧	Pratap Vardhan 💻	Simon Lydell 🐛	Yusuke Iinuma 💻
Yves M. 🔧	d07riv 🐛	mizdra 💻	sirian 🐛

💙 This package was templated with create-typescript-app.