line.js

import Diff from './base';

export const lineDiff = new Diff();
export const trimmedLineDiff = new Diff();
trimmedLineDiff.ignoreTrim = true;

lineDiff.tokenize = trimmedLineDiff.tokenize = function(value) {
  let retLines = [],
      lines = value.split(/^/m);
  for (let i = 0; i < lines.length; i++) {
    let line = lines[i],
        lastLine = lines[i - 1],
        lastLineLastChar = lastLine && lastLine[lastLine.length - 1];

    // Merge lines that may contain windows new lines
    if (line === '\n' && lastLineLastChar === '\r') {
        retLines[retLines.length - 1] = retLines[retLines.length - 1].slice(0, -1) + '\r\n';
    } else {
      if (this.ignoreTrim) {
        line = line.trim();
        // add a newline unless this is the last line.
        if (i < lines.length - 1) {
          line += '\n';
        }
      }
      retLines.push(line);
    }
  }

  return retLines;
};

export function diffLines(oldStr, newStr, callback) { return lineDiff.diff(oldStr, newStr, callback); }
export function diffTrimmedLines(oldStr, newStr, callback) { return trimmedLineDiff.diff(oldStr, newStr, callback); }