sindresorhus / detect-newline

Detect the dominant newline character of a string

detect-newline

Detect the dominant newline character of a string

Install

npm install detect-newline

Usage

import {detectNewline} from 'detect-newline';

detectNewline('foo\nbar\nbaz\r\n');
//=> '\n'

API

detectNewline(string)

Returns the detected newline or undefined when no newline character is found or \n when no dominant newline is present.

detectNewlineGraceful(unknown)

Returns the detected newline or \n when no newline character is found, no dominant newline is present, or the input is not a string.

Related

• detect-newline-cli - CLI for this module
• detect-indent - Detect the indentation of code

detect-newline's Issues

`.graceful()` method should return `\n` when given `null`

Current Behavior

// This is good/expected
detectNewline(null) // Throws TypeError.

// This is bad/unexpected/not graceful
detectNewline.graceful(null) // Throws TypeError

Expected Behavior

detectNewline.graceful(null) // Return '\n'

Expect graceful to be gracefully handle null input and return \n. Package should not throw/crash the app.

Return `undefined` when no new lines

I found a PR that actually did this too, but it was closed as out of scope. (#3)

I think this is actually a common use-case. If there's no newlines, there shouldn't be an newlines returned and the user can use the default. It's on the same bar as https://github.com/sindresorhus/detect-indent, which returns undefined as the indent when no indent is detected. This would allow someone to fall back to the OS EOL instead of \n when editing an existing file without any new lines.

Return `undefined` on equal counts?

I noticed the module has a bias towards LF, e.g. when a string contains a equal amount of LF and CRLF, it will return LF. The module's description says it returns the "dominant" variant, but when they are equal, none dominate and I think it would be more correct to return undefined.