@fluent/dedent

A template literal tag for dedenting Fluent code

Usage no npm install needed!

<script type="module">
  import fluentDedent from 'https://cdn.skypack.dev/@fluent/dedent';
</script>

README

@fluent/dedent

@fluent/dedent provides a template literal tag to dedent Fluent code. It's part of Project Fluent.

Fluent Syntax is indentation-sensitive, and @fluent/dedent offers a convenient way to include Fluent snippets in source code keeping the current level of indentation and without compromising the readability.

Installation

@fluent/dedent can be used both on the client-side and the server-side. You can install it from the npm registry or use it as a standalone script (as the FluentDedent global).

npm install @fluent/dedent

How to use

@fluent/dedent's default export is meant to be used as a template literal tag. By convention, the tag is often called ftl.

import ftl from "@fluent/dedent";

let messages = ftl`
    hello = Hello, world!
    welcome = Welcome, {$userName}!
    `;

The position of the closing backtick defines how much indent will be removed from each line of the content. If the indentation is not sufficient in any of the non-blank lines of the content, a RangeError is thrown.

import ftl from "@fluent/dedent";

let messages = ftl`
    hello = Hello, world!
  welcome = Welcome, {$userName}!
    `;

// → RangeError("Insufficient indentation in line 2.")

Content must start on a new line and must end on a line of its own. The closing delimiter must appear on a new line. The first and the last line of the input will be removed from the output. If any of them contains non-whitespace characters, a RangeError is thrown.

import ftl from "@fluent/dedent";

let message1 = "hello = Hello, world!";
let message2 = ftl`
    hello = Hello, world!
    `;

assert(message1 === message2);

If you wish to include the leading or trailing line breaks in the output, put extra blank lines in the input.

import ftl from "@fluent/dedent";

let message = ftl`

    hello = Hello, world!

    `;

assert(message === "\nhello = Hello, world!\n");