detect-indent
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7.0.1 • Public • Published

detect-indent

Detect the indentation of code

Pass in a string of any kind of text and get the indentation.

Use cases

  • Persisting the indentation when modifying a file.
  • Have new content match the existing indentation.
  • Setting the right indentation in your editor.

Install

$ npm install detect-indent

Usage

Here we modify a JSON file while persisting the indentation:

import fs from 'node:fs';
import detectIndent from 'detect-indent';

/*
{
    "ilove": "pizza"
}
*/
const file = fs.readFileSync('foo.json', 'utf8');

// Tries to detect the indentation and falls back to a default if it can't
const indent = detectIndent(file).indent || '    ';

const json = JSON.parse(file);

json.ilove = 'unicorns';

fs.writeFileSync('foo.json', JSON.stringify(json, undefined, indent));
/*
{
    "ilove": "unicorns"
}
*/

API

Accepts a string and returns an object with stats about the indentation:

  • amount {number} - Amount of indentation, for example 2
  • type {'tab' | 'space' | undefined} - Type of indentation. Possible values are 'tab', 'space' or undefined if no indentation is detected
  • indent {string} - Actual indentation

Algorithm

The current algorithm looks for the most common difference between two consecutive non-empty lines.

In the following example, even if the 4-space indentation is used 3 times whereas the 2-space one is used 2 times, it is detected as less used because there were only 2 differences with this value instead of 4 for the 2-space indentation:

html {
  box-sizing: border-box;
}

body {
  background: gray;
}

p {
    line-height: 1.3em;
    margin-top: 1em;
    text-indent: 2em;
}

Source.

Furthermore, if there are more than one most used difference, the indentation with the most lines is selected.

In the following example, the indentation is detected as 4-spaces:

body {
  background: gray;
}

p {
    line-height: 1.3em;
    margin-top: 1em;
    text-indent: 2em;
}

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Install

npm i detect-indent

Weekly Downloads

10,520,985

Version

7.0.1

License

MIT

Unpacked Size

9.75 kB

Total Files

5

Last publish

Collaborators

  • sindresorhus