To help you get started, we've collected the most common ways that detect-indent is being used within popular public projects.

expo / expo-cli / packages / package-manager / src / PackageManager.ts View on Github

private async _patchAsync(
    specs: npmPackageArg.Result[],
    packageType: 'dependencies' | 'devDependencies'
  ) {
    const pkgPath = path.join(this.options.cwd || '.', 'package.json');
    const pkgRaw = await fs.readFile(pkgPath, { encoding: 'utf8', flag: 'r' });
    const pkg = JSON.parse(pkgRaw);
    specs.forEach(spec => {
      pkg[packageType] = pkg[packageType] || {};
      pkg[packageType][spec.name!] = spec.rawSpec;
    });
    await fs.writeJson(pkgPath, pkg, {
      spaces: detectIndent(pkgRaw).indent,
      EOL: detectNewline(pkgRaw),
    });
  }
}

View more ways to use detect-indent

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;
}

Related

• detect-indent-cli - CLI for this module
• detect-newline - Detect the dominant newline character of a string
• detect-indent-rs - Rust port