diffLines.js

'use strict';

Object.defineProperty(exports, '__esModule', {
  value: true
});
exports.diffLinesRaw = exports.diffLinesUnified2 = exports.diffLinesUnified = void 0;

var _diffSequences = _interopRequireDefault(require('diff-sequences'));

var _cleanupSemantic = require('./cleanupSemantic');

var _normalizeDiffOptions = require('./normalizeDiffOptions');

var _printDiffs = require('./printDiffs');

function _interopRequireDefault(obj) {
  return obj && obj.__esModule ? obj : {default: obj};
}

/**
 * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
const isEmptyString = lines => lines.length === 1 && lines[0].length === 0; // Compare two arrays of strings line-by-line. Format as comparison lines.

const diffLinesUnified = (aLines, bLines, options) =>
  (0, _printDiffs.printDiffLines)(
    diffLinesRaw(
      isEmptyString(aLines) ? [] : aLines,
      isEmptyString(bLines) ? [] : bLines
    ),
    (0, _normalizeDiffOptions.normalizeDiffOptions)(options)
  ); // Given two pairs of arrays of strings:
// Compare the pair of comparison arrays line-by-line.
// Format the corresponding lines in the pair of displayable arrays.

exports.diffLinesUnified = diffLinesUnified;

const diffLinesUnified2 = (
  aLinesDisplay,
  bLinesDisplay,
  aLinesCompare,
  bLinesCompare,
  options
) => {
  if (isEmptyString(aLinesDisplay) && isEmptyString(aLinesCompare)) {
    aLinesDisplay = [];
    aLinesCompare = [];
  }

  if (isEmptyString(bLinesDisplay) && isEmptyString(bLinesCompare)) {
    bLinesDisplay = [];
    bLinesCompare = [];
  }

  if (
    aLinesDisplay.length !== aLinesCompare.length ||
    bLinesDisplay.length !== bLinesCompare.length
  ) {
    // Fall back to diff of display lines.
    return diffLinesUnified(aLinesDisplay, bLinesDisplay, options);
  }

  const diffs = diffLinesRaw(aLinesCompare, bLinesCompare); // Replace comparison lines with displayable lines.

  let aIndex = 0;
  let bIndex = 0;
  diffs.forEach(diff => {
    switch (diff[0]) {
      case _cleanupSemantic.DIFF_DELETE:
        diff[1] = aLinesDisplay[aIndex];
        aIndex += 1;
        break;

      case _cleanupSemantic.DIFF_INSERT:
        diff[1] = bLinesDisplay[bIndex];
        bIndex += 1;
        break;

      default:
        diff[1] = bLinesDisplay[bIndex];
        aIndex += 1;
        bIndex += 1;
    }
  });
  return (0, _printDiffs.printDiffLines)(
    diffs,
    (0, _normalizeDiffOptions.normalizeDiffOptions)(options)
  );
}; // Compare two arrays of strings line-by-line.

exports.diffLinesUnified2 = diffLinesUnified2;

const diffLinesRaw = (aLines, bLines) => {
  const aLength = aLines.length;
  const bLength = bLines.length;

  const isCommon = (aIndex, bIndex) => aLines[aIndex] === bLines[bIndex];

  const diffs = [];
  let aIndex = 0;
  let bIndex = 0;

  const foundSubsequence = (nCommon, aCommon, bCommon) => {
    for (; aIndex !== aCommon; aIndex += 1) {
      diffs.push(
        new _cleanupSemantic.Diff(_cleanupSemantic.DIFF_DELETE, aLines[aIndex])
      );
    }

    for (; bIndex !== bCommon; bIndex += 1) {
      diffs.push(
        new _cleanupSemantic.Diff(_cleanupSemantic.DIFF_INSERT, bLines[bIndex])
      );
    }

    for (; nCommon !== 0; nCommon -= 1, aIndex += 1, bIndex += 1) {
      diffs.push(
        new _cleanupSemantic.Diff(_cleanupSemantic.DIFF_EQUAL, bLines[bIndex])
      );
    }
  };

  (0, _diffSequences.default)(aLength, bLength, isCommon, foundSubsequence); // After the last common subsequence, push remaining change items.

  for (; aIndex !== aLength; aIndex += 1) {
    diffs.push(
      new _cleanupSemantic.Diff(_cleanupSemantic.DIFF_DELETE, aLines[aIndex])
    );
  }

  for (; bIndex !== bLength; bIndex += 1) {
    diffs.push(
      new _cleanupSemantic.Diff(_cleanupSemantic.DIFF_INSERT, bLines[bIndex])
    );
  }

  return diffs;
};

exports.diffLinesRaw = diffLinesRaw;