detect-eol/dist/index.js

Quickly detect the EOL used in a string.

/* IMPORT */
import { CHAR_CR, CHAR_LF } from './constants.js';
import { NEWLINE_CR, NEWLINE_CRLF, NEWLINE_LF, NEWLINE_RE } from './constants.js';
/* MAIN */
const detectEOL = (string, { fallback = '\n', window = 1024 } = {}) => {
    let CR = 0;
    let CRLF = 0;
    let LF = 0;
    for (let i = 0, l = Math.min(string.length, window); i < l; i++) {
        const char = string.charCodeAt(i);
        if (char === CHAR_CR) {
            const next = string.charCodeAt(i + 1);
            if (next === CHAR_LF) {
                CRLF += 1;
                i += 1;
            }
            else {
                CR += 1;
            }
        }
        else if (char === CHAR_LF) {
            LF += 1;
        }
    }
    const max = Math.max(LF, CRLF, CR);
    if (max) { // Found something, returning the most common one, ordered from "good newline" to "bad newline"
        if (max === LF)
            return NEWLINE_LF;
        if (max === CRLF)
            return NEWLINE_CRLF;
        if (max === CR)
            return NEWLINE_CR;
    }
    else { // Nothing found, trying to find a newline after the window
        NEWLINE_RE.lastIndex = window;
        const match = NEWLINE_RE.exec(string);
        if (match)
            return match[0];
    }
    return fallback;
};
/* EXPORT */
export default detectEOL;