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 --save detect-indent
Usage
// modify a JSON file while persisting the indentation in Node
var fs = require('fs');
var detectIndent = require('detect-indent');
/*
{
"ilove": "pizza"
}
*/
var file = fs.readFileSync('foo.json', 'utf8');
// tries to detect the indentation and falls back to a default if it can't
var indent = detectIndent(file).indent || ' ';
var json = JSON.parse(file);
json.ilove = 'unicorns';
fs.writeFileSync('foo.json', JSON.stringify(json, null, indent));
/*
{
"ilove": "unicorns"
}
*/
API
Accepts a string and returns an object with stats about the indentation:
amount: {Number} the amount of indentation, e.g.2type: {String|Null} the type of indentation. Possible values aretab,spaceornullif no indentation is detectedindent: {String} the actual indentation
CLI
$ npm install --global detect-indent
$ detect-indent --help
Usage
detect-indent <file>
echo <string> | detect-indent
Example
echo ' foo\n bar' | detect-indent | wc --chars
2
Algorithm
Look for the most common difference between two consecutive non-empty lines.
License
MIT © Sindre Sorhus