Detect the indentation of code
Pass in a string of any kind of text and get the indentation.
npm install detect-indent
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"
}
*/
Accepts a string and returns an object with stats about the indentation:
type {'tab' | 'space' | undefined} - The type of indentation. It is undefined if no indentation is detected.amount {number} - The amount of indentation. For example, 2.indent {string} - The actual indentation.The current algorithm looks for the most common difference between two consecutive non-empty lines. Single-space indentations and changes are ignored by default to prevent common false positives from comment alignment.
In the following example, even if 4-space indentation appears 3 times while 2-space appears only 2 times, the 2-space indentation is detected because there are 4 indent changes of 2 spaces vs only 2 changes of 4 spaces:
html {
box-sizing: border-box;
}
body {
background: gray;
}
p {
line-height: 1.3em;
margin-top: 1em;
text-indent: 2em;
}
Furthermore, if there are multiple indent differences with the same usage count, 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;
}