diff/lib/index.es6.js

function Diff() {}
Diff.prototype = {
  diff: function diff(oldString, newString) {
    var _options$timeout;
    var options = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {};
    var callback = options.callback;
    if (typeof options === 'function') {
      callback = options;
      options = {};
    }
    var self = this;
    function done(value) {
      value = self.postProcess(value, options);
      if (callback) {
        setTimeout(function () {
          callback(value);
        }, 0);
        return true;
      } else {
        return value;
      }
    }

    // Allow subclasses to massage the input prior to running
    oldString = this.castInput(oldString, options);
    newString = this.castInput(newString, options);
    oldString = this.removeEmpty(this.tokenize(oldString, options));
    newString = this.removeEmpty(this.tokenize(newString, options));
    var newLen = newString.length,
      oldLen = oldString.length;
    var editLength = 1;
    var maxEditLength = newLen + oldLen;
    if (options.maxEditLength != null) {
      maxEditLength = Math.min(maxEditLength, options.maxEditLength);
    }
    var maxExecutionTime = (_options$timeout = options.timeout) !== null && _options$timeout !== void 0 ? _options$timeout : Infinity;
    var abortAfterTimestamp = Date.now() + maxExecutionTime;
    var bestPath = [{
      oldPos: -1,
      lastComponent: undefined
    }];

    // Seed editLength = 0, i.e. the content starts with the same values
    var newPos = this.extractCommon(bestPath[0], newString, oldString, 0, options);
    if (bestPath[0].oldPos + 1 >= oldLen && newPos + 1 >= newLen) {
      // Identity per the equality and tokenizer
      return done(buildValues(self, bestPath[0].lastComponent, newString, oldString, self.useLongestToken));
    }

    // Once we hit the right edge of the edit graph on some diagonal k, we can
    // definitely reach the end of the edit graph in no more than k edits, so
    // there's no point in considering any moves to diagonal k+1 any more (from
    // which we're guaranteed to need at least k+1 more edits).
    // Similarly, once we've reached the bottom of the edit graph, there's no
    // point considering moves to lower diagonals.
    // We record this fact by setting minDiagonalToConsider and
    // maxDiagonalToConsider to some finite value once we've hit the edge of
    // the edit graph.
    // This optimization is not faithful to the original algorithm presented in
    // Myers's paper, which instead pointlessly extends D-paths off the end of
    // the edit graph - see page 7 of Myers's paper which notes this point
    // explicitly and illustrates it with a diagram. This has major performance
    // implications for some common scenarios. For instance, to compute a diff
    // where the new text simply appends d characters on the end of the
    // original text of length n, the true Myers algorithm will take O(n+d^2)
    // time while this optimization needs only O(n+d) time.
    var minDiagonalToConsider = -Infinity,
      maxDiagonalToConsider = Infinity;

    // Main worker method. checks all permutations of a given edit length for acceptance.
    function execEditLength() {
      for (var diagonalPath = Math.max(minDiagonalToConsider, -editLength); diagonalPath <= Math.min(maxDiagonalToConsider, editLength); diagonalPath += 2) {
        var basePath = void 0;
        var removePath = bestPath[diagonalPath - 1],
          addPath = bestPath[diagonalPath + 1];
        if (removePath) {
          // No one else is going to attempt to use this value, clear it
          bestPath[diagonalPath - 1] = undefined;
        }
        var canAdd = false;
        if (addPath) {
          // what newPos will be after we do an insertion:
          var addPathNewPos = addPath.oldPos - diagonalPath;
          canAdd = addPath && 0 <= addPathNewPos && addPathNewPos < newLen;
        }
        var canRemove = removePath && removePath.oldPos + 1 < oldLen;
        if (!canAdd && !canRemove) {
          // If this path is a terminal then prune
          bestPath[diagonalPath] = undefined;
          continue;
        }

        // Select the diagonal that we want to branch from. We select the prior
        // path whose position in the old string is the farthest from the origin
        // and does not pass the bounds of the diff graph
        if (!canRemove || canAdd && removePath.oldPos < addPath.oldPos) {
          basePath = self.addToPath(addPath, true, false, 0, options);
        } else {
          basePath = self.addToPath(removePath, false, true, 1, options);
        }
        newPos = self.extractCommon(basePath, newString, oldString, diagonalPath, options);
        if (basePath.oldPos + 1 >= oldLen && newPos + 1 >= newLen) {
          // If we have hit the end of both strings, then we are done
          return done(buildValues(self, basePath.lastComponent, newString, oldString, self.useLongestToken));
        } else {
          bestPath[diagonalPath] = basePath;
          if (basePath.oldPos + 1 >= oldLen) {
            maxDiagonalToConsider = Math.min(maxDiagonalToConsider, diagonalPath - 1);
          }
          if (newPos + 1 >= newLen) {
            minDiagonalToConsider = Math.max(minDiagonalToConsider, diagonalPath + 1);
          }
        }
      }
      editLength++;
    }

    // Performs the length of edit iteration. Is a bit fugly as this has to support the
    // sync and async mode which is never fun. Loops over execEditLength until a value
    // is produced, or until the edit length exceeds options.maxEditLength (if given),
    // in which case it will return undefined.
    if (callback) {
      (function exec() {
        setTimeout(function () {
          if (editLength > maxEditLength || Date.now() > abortAfterTimestamp) {
            return callback();
          }
          if (!execEditLength()) {
            exec();
          }
        }, 0);
      })();
    } else {
      while (editLength <= maxEditLength && Date.now() <= abortAfterTimestamp) {
        var ret = execEditLength();
        if (ret) {
          return ret;
        }
      }
    }
  },
  addToPath: function addToPath(path, added, removed, oldPosInc, options) {
    var last = path.lastComponent;
    if (last && !options.oneChangePerToken && last.added === added && last.removed === removed) {
      return {
        oldPos: path.oldPos + oldPosInc,
        lastComponent: {
          count: last.count + 1,
          added: added,
          removed: removed,
          previousComponent: last.previousComponent
        }
      };
    } else {
      return {
        oldPos: path.oldPos + oldPosInc,
        lastComponent: {
          count: 1,
          added: added,
          removed: removed,
          previousComponent: last
        }
      };
    }
  },
  extractCommon: function extractCommon(basePath, newString, oldString, diagonalPath, options) {
    var newLen = newString.length,
      oldLen = oldString.length,
      oldPos = basePath.oldPos,
      newPos = oldPos - diagonalPath,
      commonCount = 0;
    while (newPos + 1 < newLen && oldPos + 1 < oldLen && this.equals(oldString[oldPos + 1], newString[newPos + 1], options)) {
      newPos++;
      oldPos++;
      commonCount++;
      if (options.oneChangePerToken) {
        basePath.lastComponent = {
          count: 1,
          previousComponent: basePath.lastComponent,
          added: false,
          removed: false
        };
      }
    }
    if (commonCount && !options.oneChangePerToken) {
      basePath.lastComponent = {
        count: commonCount,
        previousComponent: basePath.lastComponent,
        added: false,
        removed: false
      };
    }
    basePath.oldPos = oldPos;
    return newPos;
  },
  equals: function equals(left, right, options) {
    if (options.comparator) {
      return options.comparator(left, right);
    } else {
      return left === right || options.ignoreCase && left.toLowerCase() === right.toLowerCase();
    }
  },
  removeEmpty: function removeEmpty(array) {
    var ret = [];
    for (var i = 0; i < array.length; i++) {
      if (array[i]) {
        ret.push(array[i]);
      }
    }
    return ret;
  },
  castInput: function castInput(value) {
    return value;
  },
  tokenize: function tokenize(value) {
    return Array.from(value);
  },
  join: function join(chars) {
    return chars.join('');
  },
  postProcess: function postProcess(changeObjects) {
    return changeObjects;
  }
};
function buildValues(diff, lastComponent, newString, oldString, useLongestToken) {
  // First we convert our linked list of components in reverse order to an
  // array in the right order:
  var components = [];
  var nextComponent;
  while (lastComponent) {
    components.push(lastComponent);
    nextComponent = lastComponent.previousComponent;
    delete lastComponent.previousComponent;
    lastComponent = nextComponent;
  }
  components.reverse();
  var componentPos = 0,
    componentLen = components.length,
    newPos = 0,
    oldPos = 0;
  for (; componentPos < componentLen; componentPos++) {
    var component = components[componentPos];
    if (!component.removed) {
      if (!component.added && useLongestToken) {
        var value = newString.slice(newPos, newPos + component.count);
        value = value.map(function (value, i) {
          var oldValue = oldString[oldPos + i];
          return oldValue.length > value.length ? oldValue : value;
        });
        component.value = diff.join(value);
      } else {
        component.value = diff.join(newString.slice(newPos, newPos + component.count));
      }
      newPos += component.count;

      // Common case
      if (!component.added) {
        oldPos += component.count;
      }
    } else {
      component.value = diff.join(oldString.slice(oldPos, oldPos + component.count));
      oldPos += component.count;
    }
  }
  return components;
}

var characterDiff = new Diff();
function diffChars(oldStr, newStr, options) {
  return characterDiff.diff(oldStr, newStr, options);
}

function longestCommonPrefix(str1, str2) {
  var i;
  for (i = 0; i < str1.length && i < str2.length; i++) {
    if (str1[i] != str2[i]) {
      return str1.slice(0, i);
    }
  }
  return str1.slice(0, i);
}
function longestCommonSuffix(str1, str2) {
  var i;

  // Unlike longestCommonPrefix, we need a special case to handle all scenarios
  // where we return the empty string since str1.slice(-0) will return the
  // entire string.
  if (!str1 || !str2 || str1[str1.length - 1] != str2[str2.length - 1]) {
    return '';
  }
  for (i = 0; i < str1.length && i < str2.length; i++) {
    if (str1[str1.length - (i + 1)] != str2[str2.length - (i + 1)]) {
      return str1.slice(-i);
    }
  }
  return str1.slice(-i);
}
function replacePrefix(string, oldPrefix, newPrefix) {
  if (string.slice(0, oldPrefix.length) != oldPrefix) {
    throw Error("string ".concat(JSON.stringify(string), " doesn't start with prefix ").concat(JSON.stringify(oldPrefix), "; this is a bug"));
  }
  return newPrefix + string.slice(oldPrefix.length);
}
function replaceSuffix(string, oldSuffix, newSuffix) {
  if (!oldSuffix) {
    return string + newSuffix;
  }
  if (string.slice(-oldSuffix.length) != oldSuffix) {
    throw Error("string ".concat(JSON.stringify(string), " doesn't end with suffix ").concat(JSON.stringify(oldSuffix), "; this is a bug"));
  }
  return string.slice(0, -oldSuffix.length) + newSuffix;
}
function removePrefix(string, oldPrefix) {
  return replacePrefix(string, oldPrefix, '');
}
function removeSuffix(string, oldSuffix) {
  return replaceSuffix(string, oldSuffix, '');
}
function maximumOverlap(string1, string2) {
  return string2.slice(0, overlapCount(string1, string2));
}

// Nicked from https://stackoverflow.com/a/60422853/1709587
function overlapCount(a, b) {
  // Deal with cases where the strings differ in length
  var startA = 0;
  if (a.length > b.length) {
    startA = a.length - b.length;
  }
  var endB = b.length;
  if (a.length < b.length) {
    endB = a.length;
  }
  // Create a back-reference for each index
  //   that should be followed in case of a mismatch.
  //   We only need B to make these references:
  var map = Array(endB);
  var k = 0; // Index that lags behind j
  map[0] = 0;
  for (var j = 1; j < endB; j++) {
    if (b[j] == b[k]) {
      map[j] = map[k]; // skip over the same character (optional optimisation)
    } else {
      map[j] = k;
    }
    while (k > 0 && b[j] != b[k]) {
      k = map[k];
    }
    if (b[j] == b[k]) {
      k++;
    }
  }
  // Phase 2: use these references while iterating over A
  k = 0;
  for (var i = startA; i < a.length; i++) {
    while (k > 0 && a[i] != b[k]) {
      k = map[k];
    }
    if (a[i] == b[k]) {
      k++;
    }
  }
  return k;
}

/**
 * Returns true if the string consistently uses Windows line endings.
 */
function hasOnlyWinLineEndings(string) {
  return string.includes('\r\n') && !string.startsWith('\n') && !string.match(/[^\r]\n/);
}

/**
 * Returns true if the string consistently uses Unix line endings.
 */
function hasOnlyUnixLineEndings(string) {
  return !string.includes('\r\n') && string.includes('\n');
}

// Based on https://en.wikipedia.org/wiki/Latin_script_in_Unicode
//
// Ranges and exceptions:
// Latin-1 Supplement, 0080–00FF
//  - U+00D7  × Multiplication sign
//  - U+00F7  ÷ Division sign
// Latin Extended-A, 0100–017F
// Latin Extended-B, 0180–024F
// IPA Extensions, 0250–02AF
// Spacing Modifier Letters, 02B0–02FF
//  - U+02C7  ˇ &#711;  Caron
//  - U+02D8  ˘ &#728;  Breve
//  - U+02D9  ˙ &#729;  Dot Above
//  - U+02DA  ˚ &#730;  Ring Above
//  - U+02DB  ˛ &#731;  Ogonek
//  - U+02DC  ˜ &#732;  Small Tilde
//  - U+02DD  ˝ &#733;  Double Acute Accent
// Latin Extended Additional, 1E00–1EFF
var extendedWordChars = "a-zA-Z0-9_\\u{C0}-\\u{FF}\\u{D8}-\\u{F6}\\u{F8}-\\u{2C6}\\u{2C8}-\\u{2D7}\\u{2DE}-\\u{2FF}\\u{1E00}-\\u{1EFF}";

// Each token is one of the following:
// - A punctuation mark plus the surrounding whitespace
// - A word plus the surrounding whitespace
// - Pure whitespace (but only in the special case where this the entire text
//   is just whitespace)
//
// We have to include surrounding whitespace in the tokens because the two
// alternative approaches produce horribly broken results:
// * If we just discard the whitespace, we can't fully reproduce the original
//   text from the sequence of tokens and any attempt to render the diff will
//   get the whitespace wrong.
// * If we have separate tokens for whitespace, then in a typical text every
//   second token will be a single space character. But this often results in
//   the optimal diff between two texts being a perverse one that preserves
//   the spaces between words but deletes and reinserts actual common words.
//   See https://github.com/kpdecker/jsdiff/issues/160#issuecomment-1866099640
//   for an example.
//
// Keeping the surrounding whitespace of course has implications for .equals
// and .join, not just .tokenize.

// This regex does NOT fully implement the tokenization rules described above.
// Instead, it gives runs of whitespace their own "token". The tokenize method
// then handles stitching whitespace tokens onto adjacent word or punctuation
// tokens.
var tokenizeIncludingWhitespace = new RegExp("[".concat(extendedWordChars, "]+|\\s+|[^").concat(extendedWordChars, "]"), 'ug');
var wordDiff = new Diff();
wordDiff.equals = function (left, right, options) {
  if (options.ignoreCase) {
    left = left.toLowerCase();
    right = right.toLowerCase();
  }
  return left.trim() === right.trim();
};
wordDiff.tokenize = function (value) {
  var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
  var parts;
  if (options.intlSegmenter) {
    if (options.intlSegmenter.resolvedOptions().granularity != 'word') {
      throw new Error('The segmenter passed must have a granularity of "word"');
    }
    parts = Array.from(options.intlSegmenter.segment(value), function (segment) {
      return segment.segment;
    });
  } else {
    parts = value.match(tokenizeIncludingWhitespace) || [];
  }
  var tokens = [];
  var prevPart = null;
  parts.forEach(function (part) {
    if (/\s/.test(part)) {
      if (prevPart == null) {
        tokens.push(part);
      } else {
        tokens.push(tokens.pop() + part);
      }
    } else if (/\s/.test(prevPart)) {
      if (tokens[tokens.length - 1] == prevPart) {
        tokens.push(tokens.pop() + part);
      } else {
        tokens.push(prevPart + part);
      }
    } else {
      tokens.push(part);
    }
    prevPart = part;
  });
  return tokens;
};
wordDiff.join = function (tokens) {
  // Tokens being joined here will always have appeared consecutively in the
  // same text, so we can simply strip off the leading whitespace from all the
  // tokens except the first (and except any whitespace-only tokens - but such
  // a token will always be the first and only token anyway) and then join them
  // and the whitespace around words and punctuation will end up correct.
  return tokens.map(function (token, i) {
    if (i == 0) {
      return token;
    } else {
      return token.replace(/^\s+/, '');
    }
  }).join('');
};
wordDiff.postProcess = function (changes, options) {
  if (!changes || options.oneChangePerToken) {
    return changes;
  }
  var lastKeep = null;
  // Change objects representing any insertion or deletion since the last
  // "keep" change object. There can be at most one of each.
  var insertion = null;
  var deletion = null;
  changes.forEach(function (change) {
    if (change.added) {
      insertion = change;
    } else if (change.removed) {
      deletion = change;
    } else {
      if (insertion || deletion) {
        // May be false at start of text
        dedupeWhitespaceInChangeObjects(lastKeep, deletion, insertion, change);
      }
      lastKeep = change;
      insertion = null;
      deletion = null;
    }
  });
  if (insertion || deletion) {
    dedupeWhitespaceInChangeObjects(lastKeep, deletion, insertion, null);
  }
  return changes;
};
function diffWords(oldStr, newStr, options) {
  // This option has never been documented and never will be (it's clearer to
  // just call `diffWordsWithSpace` directly if you need that behavior), but
  // has existed in jsdiff for a long time, so we retain support for it here
  // for the sake of backwards compatibility.
  if ((options === null || options === void 0 ? void 0 : options.ignoreWhitespace) != null && !options.ignoreWhitespace) {
    return diffWordsWithSpace(oldStr, newStr, options);
  }
  return wordDiff.diff(oldStr, newStr, options);
}
function dedupeWhitespaceInChangeObjects(startKeep, deletion, insertion, endKeep) {
  // Before returning, we tidy up the leading and trailing whitespace of the
  // change objects to eliminate cases where trailing whitespace in one object
  // is repeated as leading whitespace in the next.
  // Below are examples of the outcomes we want here to explain the code.
  // I=insert, K=keep, D=delete
  // 1. diffing 'foo bar baz' vs 'foo baz'
  //    Prior to cleanup, we have K:'foo ' D:' bar ' K:' baz'
  //    After cleanup, we want:   K:'foo ' D:'bar ' K:'baz'
  //
  // 2. Diffing 'foo bar baz' vs 'foo qux baz'
  //    Prior to cleanup, we have K:'foo ' D:' bar ' I:' qux ' K:' baz'
  //    After cleanup, we want K:'foo ' D:'bar' I:'qux' K:' baz'
  //
  // 3. Diffing 'foo\nbar baz' vs 'foo baz'
  //    Prior to cleanup, we have K:'foo ' D:'\nbar ' K:' baz'
  //    After cleanup, we want K'foo' D:'\nbar' K:' baz'
  //
  // 4. Diffing 'foo baz' vs 'foo\nbar baz'
  //    Prior to cleanup, we have K:'foo\n' I:'\nbar ' K:' baz'
  //    After cleanup, we ideally want K'foo' I:'\nbar' K:' baz'
  //    but don't actually manage this currently (the pre-cleanup change
  //    objects don't contain enough information to make it possible).
  //
  // 5. Diffing 'foo   bar baz' vs 'foo  baz'
  //    Prior to cleanup, we have K:'foo  ' D:'   bar ' K:'  baz'
  //    After cleanup, we want K:'foo  ' D:' bar ' K:'baz'
  //
  // Our handling is unavoidably imperfect in the case where there's a single
  // indel between keeps and the whitespace has changed. For instance, consider
  // diffing 'foo\tbar\nbaz' vs 'foo baz'. Unless we create an extra change
  // object to represent the insertion of the space character (which isn't even
  // a token), we have no way to avoid losing information about the texts'
  // original whitespace in the result we return. Still, we do our best to
  // output something that will look sensible if we e.g. print it with
  // insertions in green and deletions in red.

  // Between two "keep" change objects (or before the first or after the last
  // change object), we can have either:
  // * A "delete" followed by an "insert"
  // * Just an "insert"
  // * Just a "delete"
  // We handle the three cases separately.
  if (deletion && insertion) {
    var oldWsPrefix = deletion.value.match(/^\s*/)[0];
    var oldWsSuffix = deletion.value.match(/\s*$/)[0];
    var newWsPrefix = insertion.value.match(/^\s*/)[0];
    var newWsSuffix = insertion.value.match(/\s*$/)[0];
    if (startKeep) {
      var commonWsPrefix = longestCommonPrefix(oldWsPrefix, newWsPrefix);
      startKeep.value = replaceSuffix(startKeep.value, newWsPrefix, commonWsPrefix);
      deletion.value = removePrefix(deletion.value, commonWsPrefix);
      insertion.value = removePrefix(insertion.value, commonWsPrefix);
    }
    if (endKeep) {
      var commonWsSuffix = longestCommonSuffix(oldWsSuffix, newWsSuffix);
      endKeep.value = replacePrefix(endKeep.value, newWsSuffix, commonWsSuffix);
      deletion.value = removeSuffix(deletion.value, commonWsSuffix);
      insertion.value = removeSuffix(insertion.value, commonWsSuffix);
    }
  } else if (insertion) {
    // The whitespaces all reflect what was in the new text rather than
    // the old, so we essentially have no information about whitespace
    // insertion or deletion. We just want to dedupe the whitespace.
    // We do that by having each change object keep its trailing
    // whitespace and deleting duplicate leading whitespace where
    // present.
    if (startKeep) {
      insertion.value = insertion.value.replace(/^\s*/, '');
    }
    if (endKeep) {
      endKeep.value = endKeep.value.replace(/^\s*/, '');
    }
    // otherwise we've got a deletion and no insertion
  } else if (startKeep && endKeep) {
    var newWsFull = endKeep.value.match(/^\s*/)[0],
      delWsStart = deletion.value.match(/^\s*/)[0],
      delWsEnd = deletion.value.match(/\s*$/)[0];

    // Any whitespace that comes straight after startKeep in both the old and
    // new texts, assign to startKeep and remove from the deletion.
    var newWsStart = longestCommonPrefix(newWsFull, delWsStart);
    deletion.value = removePrefix(deletion.value, newWsStart);

    // Any whitespace that comes straight before endKeep in both the old and
    // new texts, and hasn't already been assigned to startKeep, assign to
    // endKeep and remove from the deletion.
    var newWsEnd = longestCommonSuffix(removePrefix(newWsFull, newWsStart), delWsEnd);
    deletion.value = removeSuffix(deletion.value, newWsEnd);
    endKeep.value = replacePrefix(endKeep.value, newWsFull, newWsEnd);

    // If there's any whitespace from the new text that HASN'T already been
    // assigned, assign it to the start:
    startKeep.value = replaceSuffix(startKeep.value, newWsFull, newWsFull.slice(0, newWsFull.length - newWsEnd.length));
  } else if (endKeep) {
    // We are at the start of the text. Preserve all the whitespace on
    // endKeep, and just remove whitespace from the end of deletion to the
    // extent that it overlaps with the start of endKeep.
    var endKeepWsPrefix = endKeep.value.match(/^\s*/)[0];
    var deletionWsSuffix = deletion.value.match(/\s*$/)[0];
    var overlap = maximumOverlap(deletionWsSuffix, endKeepWsPrefix);
    deletion.value = removeSuffix(deletion.value, overlap);
  } else if (startKeep) {
    // We are at the END of the text. Preserve all the whitespace on
    // startKeep, and just remove whitespace from the start of deletion to
    // the extent that it overlaps with the end of startKeep.
    var startKeepWsSuffix = startKeep.value.match(/\s*$/)[0];
    var deletionWsPrefix = deletion.value.match(/^\s*/)[0];
    var _overlap = maximumOverlap(startKeepWsSuffix, deletionWsPrefix);
    deletion.value = removePrefix(deletion.value, _overlap);
  }
}
var wordWithSpaceDiff = new Diff();
wordWithSpaceDiff.tokenize = function (value) {
  // Slightly different to the tokenizeIncludingWhitespace regex used above in
  // that this one treats each individual newline as a distinct tokens, rather
  // than merging them into other surrounding whitespace. This was requested
  // in https://github.com/kpdecker/jsdiff/issues/180 &
  //    https://github.com/kpdecker/jsdiff/issues/211
  var regex = new RegExp("(\\r?\\n)|[".concat(extendedWordChars, "]+|[^\\S\\n\\r]+|[^").concat(extendedWordChars, "]"), 'ug');
  return value.match(regex) || [];
};
function diffWordsWithSpace(oldStr, newStr, options) {
  return wordWithSpaceDiff.diff(oldStr, newStr, options);
}

function generateOptions(options, defaults) {
  if (typeof options === 'function') {
    defaults.callback = options;
  } else if (options) {
    for (var name in options) {
      /* istanbul ignore else */
      if (options.hasOwnProperty(name)) {
        defaults[name] = options[name];
      }
    }
  }
  return defaults;
}

var lineDiff = new Diff();
lineDiff.tokenize = function (value, options) {
  if (options.stripTrailingCr) {
    // remove one \r before \n to match GNU diff's --strip-trailing-cr behavior
    value = value.replace(/\r\n/g, '\n');
  }
  var retLines = [],
    linesAndNewlines = value.split(/(\n|\r\n)/);

  // Ignore the final empty token that occurs if the string ends with a new line
  if (!linesAndNewlines[linesAndNewlines.length - 1]) {
    linesAndNewlines.pop();
  }

  // Merge the content and line separators into single tokens
  for (var i = 0; i < linesAndNewlines.length; i++) {
    var line = linesAndNewlines[i];
    if (i % 2 && !options.newlineIsToken) {
      retLines[retLines.length - 1] += line;
    } else {
      retLines.push(line);
    }
  }
  return retLines;
};
lineDiff.equals = function (left, right, options) {
  // If we're ignoring whitespace, we need to normalise lines by stripping
  // whitespace before checking equality. (This has an annoying interaction
  // with newlineIsToken that requires special handling: if newlines get their
  // own token, then we DON'T want to trim the *newline* tokens down to empty
  // strings, since this would cause us to treat whitespace-only line content
  // as equal to a separator between lines, which would be weird and
  // inconsistent with the documented behavior of the options.)
  if (options.ignoreWhitespace) {
    if (!options.newlineIsToken || !left.includes('\n')) {
      left = left.trim();
    }
    if (!options.newlineIsToken || !right.includes('\n')) {
      right = right.trim();
    }
  } else if (options.ignoreNewlineAtEof && !options.newlineIsToken) {
    if (left.endsWith('\n')) {
      left = left.slice(0, -1);
    }
    if (right.endsWith('\n')) {
      right = right.slice(0, -1);
    }
  }
  return Diff.prototype.equals.call(this, left, right, options);
};
function diffLines(oldStr, newStr, callback) {
  return lineDiff.diff(oldStr, newStr, callback);
}

// Kept for backwards compatibility. This is a rather arbitrary wrapper method
// that just calls `diffLines` with `ignoreWhitespace: true`. It's confusing to
// have two ways to do exactly the same thing in the API, so we no longer
// document this one (library users should explicitly use `diffLines` with
// `ignoreWhitespace: true` instead) but we keep it around to maintain
// compatibility with code that used old versions.
function diffTrimmedLines(oldStr, newStr, callback) {
  var options = generateOptions(callback, {
    ignoreWhitespace: true
  });
  return lineDiff.diff(oldStr, newStr, options);
}

var sentenceDiff = new Diff();
sentenceDiff.tokenize = function (value) {
  return value.split(/(\S.+?[.!?])(?=\s+|$)/);
};
function diffSentences(oldStr, newStr, callback) {
  return sentenceDiff.diff(oldStr, newStr, callback);
}

var cssDiff = new Diff();
cssDiff.tokenize = function (value) {
  return value.split(/([{}:;,]|\s+)/);
};
function diffCss(oldStr, newStr, callback) {
  return cssDiff.diff(oldStr, newStr, callback);
}

function ownKeys(e, r) {
  var t = Object.keys(e);
  if (Object.getOwnPropertySymbols) {
    var o = Object.getOwnPropertySymbols(e);
    r && (o = o.filter(function (r) {
      return Object.getOwnPropertyDescriptor(e, r).enumerable;
    })), t.push.apply(t, o);
  }
  return t;
}
function _objectSpread2(e) {
  for (var r = 1; r < arguments.length; r++) {
    var t = null != arguments[r] ? arguments[r] : {};
    r % 2 ? ownKeys(Object(t), !0).forEach(function (r) {
      _defineProperty(e, r, t[r]);
    }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(e, Object.getOwnPropertyDescriptors(t)) : ownKeys(Object(t)).forEach(function (r) {
      Object.defineProperty(e, r, Object.getOwnPropertyDescriptor(t, r));
    });
  }
  return e;
}
function _toPrimitive(t, r) {
  if ("object" != typeof t || !t) return t;
  var e = t[Symbol.toPrimitive];
  if (void 0 !== e) {
    var i = e.call(t, r || "default");
    if ("object" != typeof i) return i;
    throw new TypeError("@@toPrimitive must return a primitive value.");
  }
  return ("string" === r ? String : Number)(t);
}
function _toPropertyKey(t) {
  var i = _toPrimitive(t, "string");
  return "symbol" == typeof i ? i : i + "";
}
function _typeof(o) {
  "@babel/helpers - typeof";

  return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) {
    return typeof o;
  } : function (o) {
    return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o;
  }, _typeof(o);
}
function _defineProperty(obj, key, value) {
  key = _toPropertyKey(key);
  if (key in obj) {
    Object.defineProperty(obj, key, {
      value: value,
      enumerable: true,
      configurable: true,
      writable: true
    });
  } else {
    obj[key] = value;
  }
  return obj;
}
function _toConsumableArray(arr) {
  return _arrayWithoutHoles(arr) || _iterableToArray(arr) || _unsupportedIterableToArray(arr) || _nonIterableSpread();
}
function _arrayWithoutHoles(arr) {
  if (Array.isArray(arr)) return _arrayLikeToArray(arr);
}
function _iterableToArray(iter) {
  if (typeof Symbol !== "undefined" && iter[Symbol.iterator] != null || iter["@@iterator"] != null) return Array.from(iter);
}
function _unsupportedIterableToArray(o, minLen) {
  if (!o) return;
  if (typeof o === "string") return _arrayLikeToArray(o, minLen);
  var n = Object.prototype.toString.call(o).slice(8, -1);
  if (n === "Object" && o.constructor) n = o.constructor.name;
  if (n === "Map" || n === "Set") return Array.from(o);
  if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen);
}
function _arrayLikeToArray(arr, len) {
  if (len == null || len > arr.length) len = arr.length;
  for (var i = 0, arr2 = new Array(len); i < len; i++) arr2[i] = arr[i];
  return arr2;
}
function _nonIterableSpread() {
  throw new TypeError("Invalid attempt to spread non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
}

var jsonDiff = new Diff();
// Discriminate between two lines of pretty-printed, serialized JSON where one of them has a
// dangling comma and the other doesn't. Turns out including the dangling comma yields the nicest output:
jsonDiff.useLongestToken = true;
jsonDiff.tokenize = lineDiff.tokenize;
jsonDiff.castInput = function (value, options) {
  var undefinedReplacement = options.undefinedReplacement,
    _options$stringifyRep = options.stringifyReplacer,
    stringifyReplacer = _options$stringifyRep === void 0 ? function (k, v) {
      return typeof v === 'undefined' ? undefinedReplacement : v;
    } : _options$stringifyRep;
  return typeof value === 'string' ? value : JSON.stringify(canonicalize(value, null, null, stringifyReplacer), stringifyReplacer, '  ');
};
jsonDiff.equals = function (left, right, options) {
  return Diff.prototype.equals.call(jsonDiff, left.replace(/,([\r\n])/g, '$1'), right.replace(/,([\r\n])/g, '$1'), options);
};
function diffJson(oldObj, newObj, options) {
  return jsonDiff.diff(oldObj, newObj, options);
}

// This function handles the presence of circular references by bailing out when encountering an
// object that is already on the "stack" of items being processed. Accepts an optional replacer
function canonicalize(obj, stack, replacementStack, replacer, key) {
  stack = stack || [];
  replacementStack = replacementStack || [];
  if (replacer) {
    obj = replacer(key, obj);
  }
  var i;
  for (i = 0; i < stack.length; i += 1) {
    if (stack[i] === obj) {
      return replacementStack[i];
    }
  }
  var canonicalizedObj;
  if ('[object Array]' === Object.prototype.toString.call(obj)) {
    stack.push(obj);
    canonicalizedObj = new Array(obj.length);
    replacementStack.push(canonicalizedObj);
    for (i = 0; i < obj.length; i += 1) {
      canonicalizedObj[i] = canonicalize(obj[i], stack, replacementStack, replacer, key);
    }
    stack.pop();
    replacementStack.pop();
    return canonicalizedObj;
  }
  if (obj && obj.toJSON) {
    obj = obj.toJSON();
  }
  if (_typeof(obj) === 'object' && obj !== null) {
    stack.push(obj);
    canonicalizedObj = {};
    replacementStack.push(canonicalizedObj);
    var sortedKeys = [],
      _key;
    for (_key in obj) {
      /* istanbul ignore else */
      if (Object.prototype.hasOwnProperty.call(obj, _key)) {
        sortedKeys.push(_key);
      }
    }
    sortedKeys.sort();
    for (i = 0; i < sortedKeys.length; i += 1) {
      _key = sortedKeys[i];
      canonicalizedObj[_key] = canonicalize(obj[_key], stack, replacementStack, replacer, _key);
    }
    stack.pop();
    replacementStack.pop();
  } else {
    canonicalizedObj = obj;
  }
  return canonicalizedObj;
}

var arrayDiff = new Diff();
arrayDiff.tokenize = function (value) {
  return value.slice();
};
arrayDiff.join = arrayDiff.removeEmpty = function (value) {
  return value;
};
function diffArrays(oldArr, newArr, callback) {
  return arrayDiff.diff(oldArr, newArr, callback);
}

function unixToWin(patch) {
  if (Array.isArray(patch)) {
    return patch.map(unixToWin);
  }
  return _objectSpread2(_objectSpread2({}, patch), {}, {
    hunks: patch.hunks.map(function (hunk) {
      return _objectSpread2(_objectSpread2({}, hunk), {}, {
        lines: hunk.lines.map(function (line, i) {
          var _hunk$lines;
          return line.startsWith('\\') || line.endsWith('\r') || (_hunk$lines = hunk.lines[i + 1]) !== null && _hunk$lines !== void 0 && _hunk$lines.startsWith('\\') ? line : line + '\r';
        })
      });
    })
  });
}
function winToUnix(patch) {
  if (Array.isArray(patch)) {
    return patch.map(winToUnix);
  }
  return _objectSpread2(_objectSpread2({}, patch), {}, {
    hunks: patch.hunks.map(function (hunk) {
      return _objectSpread2(_objectSpread2({}, hunk), {}, {
        lines: hunk.lines.map(function (line) {
          return line.endsWith('\r') ? line.substring(0, line.length - 1) : line;
        })
      });
    })
  });
}

/**
 * Returns true if the patch consistently uses Unix line endings (or only involves one line and has
 * no line endings).
 */
function isUnix(patch) {
  if (!Array.isArray(patch)) {
    patch = [patch];
  }
  return !patch.some(function (index) {
    return index.hunks.some(function (hunk) {
      return hunk.lines.some(function (line) {
        return !line.startsWith('\\') && line.endsWith('\r');
      });
    });
  });
}

/**
 * Returns true if the patch uses Windows line endings and only Windows line endings.
 */
function isWin(patch) {
  if (!Array.isArray(patch)) {
    patch = [patch];
  }
  return patch.some(function (index) {
    return index.hunks.some(function (hunk) {
      return hunk.lines.some(function (line) {
        return line.endsWith('\r');
      });
    });
  }) && patch.every(function (index) {
    return index.hunks.every(function (hunk) {
      return hunk.lines.every(function (line, i) {
        var _hunk$lines2;
        return line.startsWith('\\') || line.endsWith('\r') || ((_hunk$lines2 = hunk.lines[i + 1]) === null || _hunk$lines2 === void 0 ? void 0 : _hunk$lines2.startsWith('\\'));
      });
    });
  });
}

function parsePatch(uniDiff) {
  var diffstr = uniDiff.split(/\n/),
    list = [],
    i = 0;
  function parseIndex() {
    var index = {};
    list.push(index);

    // Parse diff metadata
    while (i < diffstr.length) {
      var line = diffstr[i];

      // File header found, end parsing diff metadata
      if (/^(\-\-\-|\+\+\+|@@)\s/.test(line)) {
        break;
      }

      // Diff index
      var header = /^(?:Index:|diff(?: -r \w+)+)\s+(.+?)\s*$/.exec(line);
      if (header) {
        index.index = header[1];
      }
      i++;
    }

    // Parse file headers if they are defined. Unified diff requires them, but
    // there's no technical issues to have an isolated hunk without file header
    parseFileHeader(index);
    parseFileHeader(index);

    // Parse hunks
    index.hunks = [];
    while (i < diffstr.length) {
      var _line = diffstr[i];
      if (/^(Index:\s|diff\s|\-\-\-\s|\+\+\+\s|===================================================================)/.test(_line)) {
        break;
      } else if (/^@@/.test(_line)) {
        index.hunks.push(parseHunk());
      } else if (_line) {
        throw new Error('Unknown line ' + (i + 1) + ' ' + JSON.stringify(_line));
      } else {
        i++;
      }
    }
  }

  // Parses the --- and +++ headers, if none are found, no lines
  // are consumed.
  function parseFileHeader(index) {
    var fileHeader = /^(---|\+\+\+)\s+(.*)\r?$/.exec(diffstr[i]);
    if (fileHeader) {
      var keyPrefix = fileHeader[1] === '---' ? 'old' : 'new';
      var data = fileHeader[2].split('\t', 2);
      var fileName = data[0].replace(/\\\\/g, '\\');
      if (/^".*"$/.test(fileName)) {
        fileName = fileName.substr(1, fileName.length - 2);
      }
      index[keyPrefix + 'FileName'] = fileName;
      index[keyPrefix + 'Header'] = (data[1] || '').trim();
      i++;
    }
  }

  // Parses a hunk
  // This assumes that we are at the start of a hunk.
  function parseHunk() {
    var chunkHeaderIndex = i,
      chunkHeaderLine = diffstr[i++],
      chunkHeader = chunkHeaderLine.split(/@@ -(\d+)(?:,(\d+))? \+(\d+)(?:,(\d+))? @@/);
    var hunk = {
      oldStart: +chunkHeader[1],
      oldLines: typeof chunkHeader[2] === 'undefined' ? 1 : +chunkHeader[2],
      newStart: +chunkHeader[3],
      newLines: typeof chunkHeader[4] === 'undefined' ? 1 : +chunkHeader[4],
      lines: []
    };

    // Unified Diff Format quirk: If the chunk size is 0,
    // the first number is one lower than one would expect.
    // https://www.artima.com/weblogs/viewpost.jsp?thread=164293
    if (hunk.oldLines === 0) {
      hunk.oldStart += 1;
    }
    if (hunk.newLines === 0) {
      hunk.newStart += 1;
    }
    var addCount = 0,
      removeCount = 0;
    for (; i < diffstr.length && (removeCount < hunk.oldLines || addCount < hunk.newLines || (_diffstr$i = diffstr[i]) !== null && _diffstr$i !== void 0 && _diffstr$i.startsWith('\\')); i++) {
      var _diffstr$i;
      var operation = diffstr[i].length == 0 && i != diffstr.length - 1 ? ' ' : diffstr[i][0];
      if (operation === '+' || operation === '-' || operation === ' ' || operation === '\\') {
        hunk.lines.push(diffstr[i]);
        if (operation === '+') {
          addCount++;
        } else if (operation === '-') {
          removeCount++;
        } else if (operation === ' ') {
          addCount++;
          removeCount++;
        }
      } else {
        throw new Error("Hunk at line ".concat(chunkHeaderIndex + 1, " contained invalid line ").concat(diffstr[i]));
      }
    }

    // Handle the empty block count case
    if (!addCount && hunk.newLines === 1) {
      hunk.newLines = 0;
    }
    if (!removeCount && hunk.oldLines === 1) {
      hunk.oldLines = 0;
    }

    // Perform sanity checking
    if (addCount !== hunk.newLines) {
      throw new Error('Added line count did not match for hunk at line ' + (chunkHeaderIndex + 1));
    }
    if (removeCount !== hunk.oldLines) {
      throw new Error('Removed line count did not match for hunk at line ' + (chunkHeaderIndex + 1));
    }
    return hunk;
  }
  while (i < diffstr.length) {
    parseIndex();
  }
  return list;
}

// Iterator that traverses in the range of [min, max], stepping
// by distance from a given start position. I.e. for [0, 4], with
// start of 2, this will iterate 2, 3, 1, 4, 0.
function distanceIterator (start, minLine, maxLine) {
  var wantForward = true,
    backwardExhausted = false,
    forwardExhausted = false,
    localOffset = 1;
  return function iterator() {
    if (wantForward && !forwardExhausted) {
      if (backwardExhausted) {
        localOffset++;
      } else {
        wantForward = false;
      }

      // Check if trying to fit beyond text length, and if not, check it fits
      // after offset location (or desired location on first iteration)
      if (start + localOffset <= maxLine) {
        return start + localOffset;
      }
      forwardExhausted = true;
    }
    if (!backwardExhausted) {
      if (!forwardExhausted) {
        wantForward = true;
      }

      // Check if trying to fit before text beginning, and if not, check it fits
      // before offset location
      if (minLine <= start - localOffset) {
        return start - localOffset++;
      }
      backwardExhausted = true;
      return iterator();
    }

    // We tried to fit hunk before text beginning and beyond text length, then
    // hunk can't fit on the text. Return undefined
  };
}

function applyPatch(source, uniDiff) {
  var options = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {};
  if (typeof uniDiff === 'string') {
    uniDiff = parsePatch(uniDiff);
  }
  if (Array.isArray(uniDiff)) {
    if (uniDiff.length > 1) {
      throw new Error('applyPatch only works with a single input.');
    }
    uniDiff = uniDiff[0];
  }
  if (options.autoConvertLineEndings || options.autoConvertLineEndings == null) {
    if (hasOnlyWinLineEndings(source) && isUnix(uniDiff)) {
      uniDiff = unixToWin(uniDiff);
    } else if (hasOnlyUnixLineEndings(source) && isWin(uniDiff)) {
      uniDiff = winToUnix(uniDiff);
    }
  }

  // Apply the diff to the input
  var lines = source.split('\n'),
    hunks = uniDiff.hunks,
    compareLine = options.compareLine || function (lineNumber, line, operation, patchContent) {
      return line === patchContent;
    },
    fuzzFactor = options.fuzzFactor || 0,
    minLine = 0;
  if (fuzzFactor < 0 || !Number.isInteger(fuzzFactor)) {
    throw new Error('fuzzFactor must be a non-negative integer');
  }

  // Special case for empty patch.
  if (!hunks.length) {
    return source;
  }

  // Before anything else, handle EOFNL insertion/removal. If the patch tells us to make a change
  // to the EOFNL that is redundant/impossible - i.e. to remove a newline that's not there, or add a
  // newline that already exists - then we either return false and fail to apply the patch (if
  // fuzzFactor is 0) or simply ignore the problem and do nothing (if fuzzFactor is >0).
  // If we do need to remove/add a newline at EOF, this will always be in the final hunk:
  var prevLine = '',
    removeEOFNL = false,
    addEOFNL = false;
  for (var i = 0; i < hunks[hunks.length - 1].lines.length; i++) {
    var line = hunks[hunks.length - 1].lines[i];
    if (line[0] == '\\') {
      if (prevLine[0] == '+') {
        removeEOFNL = true;
      } else if (prevLine[0] == '-') {
        addEOFNL = true;
      }
    }
    prevLine = line;
  }
  if (removeEOFNL) {
    if (addEOFNL) {
      // This means the final line gets changed but doesn't have a trailing newline in either the
      // original or patched version. In that case, we do nothing if fuzzFactor > 0, and if
      // fuzzFactor is 0, we simply validate that the source file has no trailing newline.
      if (!fuzzFactor && lines[lines.length - 1] == '') {
        return false;
      }
    } else if (lines[lines.length - 1] == '') {
      lines.pop();
    } else if (!fuzzFactor) {
      return false;
    }
  } else if (addEOFNL) {
    if (lines[lines.length - 1] != '') {
      lines.push('');
    } else if (!fuzzFactor) {
      return false;
    }
  }

  /**
   * Checks if the hunk can be made to fit at the provided location with at most `maxErrors`
   * insertions, substitutions, or deletions, while ensuring also that:
   * - lines deleted in the hunk match exactly, and
   * - wherever an insertion operation or block of insertion operations appears in the hunk, the
   *   immediately preceding and following lines of context match exactly
   *
   * `toPos` should be set such that lines[toPos] is meant to match hunkLines[0].
   *
   * If the hunk can be applied, returns an object with properties `oldLineLastI` and
   * `replacementLines`. Otherwise, returns null.
   */
  function applyHunk(hunkLines, toPos, maxErrors) {
    var hunkLinesI = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : 0;
    var lastContextLineMatched = arguments.length > 4 && arguments[4] !== undefined ? arguments[4] : true;
    var patchedLines = arguments.length > 5 && arguments[5] !== undefined ? arguments[5] : [];
    var patchedLinesLength = arguments.length > 6 && arguments[6] !== undefined ? arguments[6] : 0;
    var nConsecutiveOldContextLines = 0;
    var nextContextLineMustMatch = false;
    for (; hunkLinesI < hunkLines.length; hunkLinesI++) {
      var hunkLine = hunkLines[hunkLinesI],
        operation = hunkLine.length > 0 ? hunkLine[0] : ' ',
        content = hunkLine.length > 0 ? hunkLine.substr(1) : hunkLine;
      if (operation === '-') {
        if (compareLine(toPos + 1, lines[toPos], operation, content)) {
          toPos++;
          nConsecutiveOldContextLines = 0;
        } else {
          if (!maxErrors || lines[toPos] == null) {
            return null;
          }
          patchedLines[patchedLinesLength] = lines[toPos];
          return applyHunk(hunkLines, toPos + 1, maxErrors - 1, hunkLinesI, false, patchedLines, patchedLinesLength + 1);
        }
      }
      if (operation === '+') {
        if (!lastContextLineMatched) {
          return null;
        }
        patchedLines[patchedLinesLength] = content;
        patchedLinesLength++;
        nConsecutiveOldContextLines = 0;
        nextContextLineMustMatch = true;
      }
      if (operation === ' ') {
        nConsecutiveOldContextLines++;
        patchedLines[patchedLinesLength] = lines[toPos];
        if (compareLine(toPos + 1, lines[toPos], operation, content)) {
          patchedLinesLength++;
          lastContextLineMatched = true;
          nextContextLineMustMatch = false;
          toPos++;
        } else {
          if (nextContextLineMustMatch || !maxErrors) {
            return null;
          }

          // Consider 3 possibilities in sequence:
          // 1. lines contains a *substitution* not included in the patch context, or
          // 2. lines contains an *insertion* not included in the patch context, or
          // 3. lines contains a *deletion* not included in the patch context
          // The first two options are of course only possible if the line from lines is non-null -
          // i.e. only option 3 is possible if we've overrun the end of the old file.
          return lines[toPos] && (applyHunk(hunkLines, toPos + 1, maxErrors - 1, hunkLinesI + 1, false, patchedLines, patchedLinesLength + 1) || applyHunk(hunkLines, toPos + 1, maxErrors - 1, hunkLinesI, false, patchedLines, patchedLinesLength + 1)) || applyHunk(hunkLines, toPos, maxErrors - 1, hunkLinesI + 1, false, patchedLines, patchedLinesLength);
        }
      }
    }

    // Before returning, trim any unmodified context lines off the end of patchedLines and reduce
    // toPos (and thus oldLineLastI) accordingly. This allows later hunks to be applied to a region
    // that starts in this hunk's trailing context.
    patchedLinesLength -= nConsecutiveOldContextLines;
    toPos -= nConsecutiveOldContextLines;
    patchedLines.length = patchedLinesLength;
    return {
      patchedLines: patchedLines,
      oldLineLastI: toPos - 1
    };
  }
  var resultLines = [];

  // Search best fit offsets for each hunk based on the previous ones
  var prevHunkOffset = 0;
  for (var _i = 0; _i < hunks.length; _i++) {
    var hunk = hunks[_i];
    var hunkResult = void 0;
    var maxLine = lines.length - hunk.oldLines + fuzzFactor;
    var toPos = void 0;
    for (var maxErrors = 0; maxErrors <= fuzzFactor; maxErrors++) {
      toPos = hunk.oldStart + prevHunkOffset - 1;
      var iterator = distanceIterator(toPos, minLine, maxLine);
      for (; toPos !== undefined; toPos = iterator()) {
        hunkResult = applyHunk(hunk.lines, toPos, maxErrors);
        if (hunkResult) {
          break;
        }
      }
      if (hunkResult) {
        break;
      }
    }
    if (!hunkResult) {
      return false;
    }

    // Copy everything from the end of where we applied the last hunk to the start of this hunk
    for (var _i2 = minLine; _i2 < toPos; _i2++) {
      resultLines.push(lines[_i2]);
    }

    // Add the lines produced by applying the hunk:
    for (var _i3 = 0; _i3 < hunkResult.patchedLines.length; _i3++) {
      var _line = hunkResult.patchedLines[_i3];
      resultLines.push(_line);
    }

    // Set lower text limit to end of the current hunk, so next ones don't try
    // to fit over already patched text
    minLine = hunkResult.oldLineLastI + 1;

    // Note the offset between where the patch said the hunk should've applied and where we
    // applied it, so we can adjust future hunks accordingly:
    prevHunkOffset = toPos + 1 - hunk.oldStart;
  }

  // Copy over the rest of the lines from the old text
  for (var _i4 = minLine; _i4 < lines.length; _i4++) {
    resultLines.push(lines[_i4]);
  }
  return resultLines.join('\n');
}

// Wrapper that supports multiple file patches via callbacks.
function applyPatches(uniDiff, options) {
  if (typeof uniDiff === 'string') {
    uniDiff = parsePatch(uniDiff);
  }
  var currentIndex = 0;
  function processIndex() {
    var index = uniDiff[currentIndex++];
    if (!index) {
      return options.complete();
    }
    options.loadFile(index, function (err, data) {
      if (err) {
        return options.complete(err);
      }
      var updatedContent = applyPatch(data, index, options);
      options.patched(index, updatedContent, function (err) {
        if (err) {
          return options.complete(err);
        }
        processIndex();
      });
    });
  }
  processIndex();
}

function structuredPatch(oldFileName, newFileName, oldStr, newStr, oldHeader, newHeader, options) {
  if (!options) {
    options = {};
  }
  if (typeof options === 'function') {
    options = {
      callback: options
    };
  }
  if (typeof options.context === 'undefined') {
    options.context = 4;
  }
  if (options.newlineIsToken) {
    throw new Error('newlineIsToken may not be used with patch-generation functions, only with diffing functions');
  }
  if (!options.callback) {
    return diffLinesResultToPatch(diffLines(oldStr, newStr, options));
  } else {
    var _options = options,
      _callback = _options.callback;
    diffLines(oldStr, newStr, _objectSpread2(_objectSpread2({}, options), {}, {
      callback: function callback(diff) {
        var patch = diffLinesResultToPatch(diff);
        _callback(patch);
      }
    }));
  }
  function diffLinesResultToPatch(diff) {
    // STEP 1: Build up the patch with no "\ No newline at end of file" lines and with the arrays
    //         of lines containing trailing newline characters. We'll tidy up later...

    if (!diff) {
      return;
    }
    diff.push({
      value: '',
      lines: []
    }); // Append an empty value to make cleanup easier

    function contextLines(lines) {
      return lines.map(function (entry) {
        return ' ' + entry;
      });
    }
    var hunks = [];
    var oldRangeStart = 0,
      newRangeStart = 0,
      curRange = [],
      oldLine = 1,
      newLine = 1;
    var _loop = function _loop() {
      var current = diff[i],
        lines = current.lines || splitLines(current.value);
      current.lines = lines;
      if (current.added || current.removed) {
        var _curRange;
        // If we have previous context, start with that
        if (!oldRangeStart) {
          var prev = diff[i - 1];
          oldRangeStart = oldLine;
          newRangeStart = newLine;
          if (prev) {
            curRange = options.context > 0 ? contextLines(prev.lines.slice(-options.context)) : [];
            oldRangeStart -= curRange.length;
            newRangeStart -= curRange.length;
          }
        }

        // Output our changes
        (_curRange = curRange).push.apply(_curRange, _toConsumableArray(lines.map(function (entry) {
          return (current.added ? '+' : '-') + entry;
        })));

        // Track the updated file position
        if (current.added) {
          newLine += lines.length;
        } else {
          oldLine += lines.length;
        }
      } else {
        // Identical context lines. Track line changes
        if (oldRangeStart) {
          // Close out any changes that have been output (or join overlapping)
          if (lines.length <= options.context * 2 && i < diff.length - 2) {
            var _curRange2;
            // Overlapping
            (_curRange2 = curRange).push.apply(_curRange2, _toConsumableArray(contextLines(lines)));
          } else {
            var _curRange3;
            // end the range and output
            var contextSize = Math.min(lines.length, options.context);
            (_curRange3 = curRange).push.apply(_curRange3, _toConsumableArray(contextLines(lines.slice(0, contextSize))));
            var _hunk = {
              oldStart: oldRangeStart,
              oldLines: oldLine - oldRangeStart + contextSize,
              newStart: newRangeStart,
              newLines: newLine - newRangeStart + contextSize,
              lines: curRange
            };
            hunks.push(_hunk);
            oldRangeStart = 0;
            newRangeStart = 0;
            curRange = [];
          }
        }
        oldLine += lines.length;
        newLine += lines.length;
      }
    };
    for (var i = 0; i < diff.length; i++) {
      _loop();
    }

    // Step 2: eliminate the trailing `\n` from each line of each hunk, and, where needed, add
    //         "\ No newline at end of file".
    for (var _i = 0, _hunks = hunks; _i < _hunks.length; _i++) {
      var hunk = _hunks[_i];
      for (var _i2 = 0; _i2 < hunk.lines.length; _i2++) {
        if (hunk.lines[_i2].endsWith('\n')) {
          hunk.lines[_i2] = hunk.lines[_i2].slice(0, -1);
        } else {
          hunk.lines.splice(_i2 + 1, 0, '\\ No newline at end of file');
          _i2++; // Skip the line we just added, then continue iterating
        }
      }
    }
    return {
      oldFileName: oldFileName,
      newFileName: newFileName,
      oldHeader: oldHeader,
      newHeader: newHeader,
      hunks: hunks
    };
  }
}
function formatPatch(diff) {
  if (Array.isArray(diff)) {
    return diff.map(formatPatch).join('\n');
  }
  var ret = [];
  if (diff.oldFileName == diff.newFileName) {
    ret.push('Index: ' + diff.oldFileName);
  }
  ret.push('===================================================================');
  ret.push('--- ' + diff.oldFileName + (typeof diff.oldHeader === 'undefined' ? '' : '\t' + diff.oldHeader));
  ret.push('+++ ' + diff.newFileName + (typeof diff.newHeader === 'undefined' ? '' : '\t' + diff.newHeader));
  for (var i = 0; i < diff.hunks.length; i++) {
    var hunk = diff.hunks[i];
    // Unified Diff Format quirk: If the chunk size is 0,
    // the first number is one lower than one would expect.
    // https://www.artima.com/weblogs/viewpost.jsp?thread=164293
    if (hunk.oldLines === 0) {
      hunk.oldStart -= 1;
    }
    if (hunk.newLines === 0) {
      hunk.newStart -= 1;
    }
    ret.push('@@ -' + hunk.oldStart + ',' + hunk.oldLines + ' +' + hunk.newStart + ',' + hunk.newLines + ' @@');
    ret.push.apply(ret, hunk.lines);
  }
  return ret.join('\n') + '\n';
}
function createTwoFilesPatch(oldFileName, newFileName, oldStr, newStr, oldHeader, newHeader, options) {
  var _options2;
  if (typeof options === 'function') {
    options = {
      callback: options
    };
  }
  if (!((_options2 = options) !== null && _options2 !== void 0 && _options2.callback)) {
    var patchObj = structuredPatch(oldFileName, newFileName, oldStr, newStr, oldHeader, newHeader, options);
    if (!patchObj) {
      return;
    }
    return formatPatch(patchObj);
  } else {
    var _options3 = options,
      _callback2 = _options3.callback;
    structuredPatch(oldFileName, newFileName, oldStr, newStr, oldHeader, newHeader, _objectSpread2(_objectSpread2({}, options), {}, {
      callback: function callback(patchObj) {
        if (!patchObj) {
          _callback2();
        } else {
          _callback2(formatPatch(patchObj));
        }
      }
    }));
  }
}
function createPatch(fileName, oldStr, newStr, oldHeader, newHeader, options) {
  return createTwoFilesPatch(fileName, fileName, oldStr, newStr, oldHeader, newHeader, options);
}

/**
 * Split `text` into an array of lines, including the trailing newline character (where present)
 */
function splitLines(text) {
  var hasTrailingNl = text.endsWith('\n');
  var result = text.split('\n').map(function (line) {
    return line + '\n';
  });
  if (hasTrailingNl) {
    result.pop();
  } else {
    result.push(result.pop().slice(0, -1));
  }
  return result;
}

function arrayEqual(a, b) {
  if (a.length !== b.length) {
    return false;
  }
  return arrayStartsWith(a, b);
}
function arrayStartsWith(array, start) {
  if (start.length > array.length) {
    return false;
  }
  for (var i = 0; i < start.length; i++) {
    if (start[i] !== array[i]) {
      return false;
    }
  }
  return true;
}

function calcLineCount(hunk) {
  var _calcOldNewLineCount = calcOldNewLineCount(hunk.lines),
    oldLines = _calcOldNewLineCount.oldLines,
    newLines = _calcOldNewLineCount.newLines;
  if (oldLines !== undefined) {
    hunk.oldLines = oldLines;
  } else {
    delete hunk.oldLines;
  }
  if (newLines !== undefined) {
    hunk.newLines = newLines;
  } else {
    delete hunk.newLines;
  }
}
function merge(mine, theirs, base) {
  mine = loadPatch(mine, base);
  theirs = loadPatch(theirs, base);
  var ret = {};

  // For index we just let it pass through as it doesn't have any necessary meaning.
  // Leaving sanity checks on this to the API consumer that may know more about the
  // meaning in their own context.
  if (mine.index || theirs.index) {
    ret.index = mine.index || theirs.index;
  }
  if (mine.newFileName || theirs.newFileName) {
    if (!fileNameChanged(mine)) {
      // No header or no change in ours, use theirs (and ours if theirs does not exist)
      ret.oldFileName = theirs.oldFileName || mine.oldFileName;
      ret.newFileName = theirs.newFileName || mine.newFileName;
      ret.oldHeader = theirs.oldHeader || mine.oldHeader;
      ret.newHeader = theirs.newHeader || mine.newHeader;
    } else if (!fileNameChanged(theirs)) {
      // No header or no change in theirs, use ours
      ret.oldFileName = mine.oldFileName;
      ret.newFileName = mine.newFileName;
      ret.oldHeader = mine.oldHeader;
      ret.newHeader = mine.newHeader;
    } else {
      // Both changed... figure it out
      ret.oldFileName = selectField(ret, mine.oldFileName, theirs.oldFileName);
      ret.newFileName = selectField(ret, mine.newFileName, theirs.newFileName);
      ret.oldHeader = selectField(ret, mine.oldHeader, theirs.oldHeader);
      ret.newHeader = selectField(ret, mine.newHeader, theirs.newHeader);
    }
  }
  ret.hunks = [];
  var mineIndex = 0,
    theirsIndex = 0,
    mineOffset = 0,
    theirsOffset = 0;
  while (mineIndex < mine.hunks.length || theirsIndex < theirs.hunks.length) {
    var mineCurrent = mine.hunks[mineIndex] || {
        oldStart: Infinity
      },
      theirsCurrent = theirs.hunks[theirsIndex] || {
        oldStart: Infinity
      };
    if (hunkBefore(mineCurrent, theirsCurrent)) {
      // This patch does not overlap with any of the others, yay.
      ret.hunks.push(cloneHunk(mineCurrent, mineOffset));
      mineIndex++;
      theirsOffset += mineCurrent.newLines - mineCurrent.oldLines;
    } else if (hunkBefore(theirsCurrent, mineCurrent)) {
      // This patch does not overlap with any of the others, yay.
      ret.hunks.push(cloneHunk(theirsCurrent, theirsOffset));
      theirsIndex++;
      mineOffset += theirsCurrent.newLines - theirsCurrent.oldLines;
    } else {
      // Overlap, merge as best we can
      var mergedHunk = {
        oldStart: Math.min(mineCurrent.oldStart, theirsCurrent.oldStart),
        oldLines: 0,
        newStart: Math.min(mineCurrent.newStart + mineOffset, theirsCurrent.oldStart + theirsOffset),
        newLines: 0,
        lines: []
      };
      mergeLines(mergedHunk, mineCurrent.oldStart, mineCurrent.lines, theirsCurrent.oldStart, theirsCurrent.lines);
      theirsIndex++;
      mineIndex++;
      ret.hunks.push(mergedHunk);
    }
  }
  return ret;
}
function loadPatch(param, base) {
  if (typeof param === 'string') {
    if (/^@@/m.test(param) || /^Index:/m.test(param)) {
      return parsePatch(param)[0];
    }
    if (!base) {
      throw new Error('Must provide a base reference or pass in a patch');
    }
    return structuredPatch(undefined, undefined, base, param);
  }
  return param;
}
function fileNameChanged(patch) {
  return patch.newFileName && patch.newFileName !== patch.oldFileName;
}
function selectField(index, mine, theirs) {
  if (mine === theirs) {
    return mine;
  } else {
    index.conflict = true;
    return {
      mine: mine,
      theirs: theirs
    };
  }
}
function hunkBefore(test, check) {
  return test.oldStart < check.oldStart && test.oldStart + test.oldLines < check.oldStart;
}
function cloneHunk(hunk, offset) {
  return {
    oldStart: hunk.oldStart,
    oldLines: hunk.oldLines,
    newStart: hunk.newStart + offset,
    newLines: hunk.newLines,
    lines: hunk.lines
  };
}
function mergeLines(hunk, mineOffset, mineLines, theirOffset, theirLines) {
  // This will generally result in a conflicted hunk, but there are cases where the context
  // is the only overlap where we can successfully merge the content here.
  var mine = {
      offset: mineOffset,
      lines: mineLines,
      index: 0
    },
    their = {
      offset: theirOffset,
      lines: theirLines,
      index: 0
    };

  // Handle any leading content
  insertLeading(hunk, mine, their);
  insertLeading(hunk, their, mine);

  // Now in the overlap content. Scan through and select the best changes from each.
  while (mine.index < mine.lines.length && their.index < their.lines.length) {
    var mineCurrent = mine.lines[mine.index],
      theirCurrent = their.lines[their.index];
    if ((mineCurrent[0] === '-' || mineCurrent[0] === '+') && (theirCurrent[0] === '-' || theirCurrent[0] === '+')) {
      // Both modified ...
      mutualChange(hunk, mine, their);
    } else if (mineCurrent[0] === '+' && theirCurrent[0] === ' ') {
      var _hunk$lines;
      // Mine inserted
      (_hunk$lines = hunk.lines).push.apply(_hunk$lines, _toConsumableArray(collectChange(mine)));
    } else if (theirCurrent[0] === '+' && mineCurrent[0] === ' ') {
      var _hunk$lines2;
      // Theirs inserted
      (_hunk$lines2 = hunk.lines).push.apply(_hunk$lines2, _toConsumableArray(collectChange(their)));
    } else if (mineCurrent[0] === '-' && theirCurrent[0] === ' ') {
      // Mine removed or edited
      removal(hunk, mine, their);
    } else if (theirCurrent[0] === '-' && mineCurrent[0] === ' ') {
      // Their removed or edited
      removal(hunk, their, mine, true);
    } else if (mineCurrent === theirCurrent) {
      // Context identity
      hunk.lines.push(mineCurrent);
      mine.index++;
      their.index++;
    } else {
      // Context mismatch
      conflict(hunk, collectChange(mine), collectChange(their));
    }
  }

  // Now push anything that may be remaining
  insertTrailing(hunk, mine);
  insertTrailing(hunk, their);
  calcLineCount(hunk);
}
function mutualChange(hunk, mine, their) {
  var myChanges = collectChange(mine),
    theirChanges = collectChange(their);
  if (allRemoves(myChanges) && allRemoves(theirChanges)) {
    // Special case for remove changes that are supersets of one another
    if (arrayStartsWith(myChanges, theirChanges) && skipRemoveSuperset(their, myChanges, myChanges.length - theirChanges.length)) {
      var _hunk$lines3;
      (_hunk$lines3 = hunk.lines).push.apply(_hunk$lines3, _toConsumableArray(myChanges));
      return;
    } else if (arrayStartsWith(theirChanges, myChanges) && skipRemoveSuperset(mine, theirChanges, theirChanges.length - myChanges.length)) {
      var _hunk$lines4;
      (_hunk$lines4 = hunk.lines).push.apply(_hunk$lines4, _toConsumableArray(theirChanges));
      return;
    }
  } else if (arrayEqual(myChanges, theirChanges)) {
    var _hunk$lines5;
    (_hunk$lines5 = hunk.lines).push.apply(_hunk$lines5, _toConsumableArray(myChanges));
    return;
  }
  conflict(hunk, myChanges, theirChanges);
}
function removal(hunk, mine, their, swap) {
  var myChanges = collectChange(mine),
    theirChanges = collectContext(their, myChanges);
  if (theirChanges.merged) {
    var _hunk$lines6;
    (_hunk$lines6 = hunk.lines).push.apply(_hunk$lines6, _toConsumableArray(theirChanges.merged));
  } else {
    conflict(hunk, swap ? theirChanges : myChanges, swap ? myChanges : theirChanges);
  }
}
function conflict(hunk, mine, their) {
  hunk.conflict = true;
  hunk.lines.push({
    conflict: true,
    mine: mine,
    theirs: their
  });
}
function insertLeading(hunk, insert, their) {
  while (insert.offset < their.offset && insert.index < insert.lines.length) {
    var line = insert.lines[insert.index++];
    hunk.lines.push(line);
    insert.offset++;
  }
}
function insertTrailing(hunk, insert) {
  while (insert.index < insert.lines.length) {
    var line = insert.lines[insert.index++];
    hunk.lines.push(line);
  }
}
function collectChange(state) {
  var ret = [],
    operation = state.lines[state.index][0];
  while (state.index < state.lines.length) {
    var line = state.lines[state.index];

    // Group additions that are immediately after subtractions and treat them as one "atomic" modify change.
    if (operation === '-' && line[0] === '+') {
      operation = '+';
    }
    if (operation === line[0]) {
      ret.push(line);
      state.index++;
    } else {
      break;
    }
  }
  return ret;
}
function collectContext(state, matchChanges) {
  var changes = [],
    merged = [],
    matchIndex = 0,
    contextChanges = false,
    conflicted = false;
  while (matchIndex < matchChanges.length && state.index < state.lines.length) {
    var change = state.lines[state.index],
      match = matchChanges[matchIndex];

    // Once we've hit our add, then we are done
    if (match[0] === '+') {
      break;
    }
    contextChanges = contextChanges || change[0] !== ' ';
    merged.push(match);
    matchIndex++;

    // Consume any additions in the other block as a conflict to attempt
    // to pull in the remaining context after this
    if (change[0] === '+') {
      conflicted = true;
      while (change[0] === '+') {
        changes.push(change);
        change = state.lines[++state.index];
      }
    }
    if (match.substr(1) === change.substr(1)) {
      changes.push(change);
      state.index++;
    } else {
      conflicted = true;
    }
  }
  if ((matchChanges[matchIndex] || '')[0] === '+' && contextChanges) {
    conflicted = true;
  }
  if (conflicted) {
    return changes;
  }
  while (matchIndex < matchChanges.length) {
    merged.push(matchChanges[matchIndex++]);
  }
  return {
    merged: merged,
    changes: changes
  };
}
function allRemoves(changes) {
  return changes.reduce(function (prev, change) {
    return prev && change[0] === '-';
  }, true);
}
function skipRemoveSuperset(state, removeChanges, delta) {
  for (var i = 0; i < delta; i++) {
    var changeContent = removeChanges[removeChanges.length - delta + i].substr(1);
    if (state.lines[state.index + i] !== ' ' + changeContent) {
      return false;
    }
  }
  state.index += delta;
  return true;
}
function calcOldNewLineCount(lines) {
  var oldLines = 0;
  var newLines = 0;
  lines.forEach(function (line) {
    if (typeof line !== 'string') {
      var myCount = calcOldNewLineCount(line.mine);
      var theirCount = calcOldNewLineCount(line.theirs);
      if (oldLines !== undefined) {
        if (myCount.oldLines === theirCount.oldLines) {
          oldLines += myCount.oldLines;
        } else {
          oldLines = undefined;
        }
      }
      if (newLines !== undefined) {
        if (myCount.newLines === theirCount.newLines) {
          newLines += myCount.newLines;
        } else {
          newLines = undefined;
        }
      }
    } else {
      if (newLines !== undefined && (line[0] === '+' || line[0] === ' ')) {
        newLines++;
      }
      if (oldLines !== undefined && (line[0] === '-' || line[0] === ' ')) {
        oldLines++;
      }
    }
  });
  return {
    oldLines: oldLines,
    newLines: newLines
  };
}

function reversePatch(structuredPatch) {
  if (Array.isArray(structuredPatch)) {
    return structuredPatch.map(reversePatch).reverse();
  }
  return _objectSpread2(_objectSpread2({}, structuredPatch), {}, {
    oldFileName: structuredPatch.newFileName,
    oldHeader: structuredPatch.newHeader,
    newFileName: structuredPatch.oldFileName,
    newHeader: structuredPatch.oldHeader,
    hunks: structuredPatch.hunks.map(function (hunk) {
      return {
        oldLines: hunk.newLines,
        oldStart: hunk.newStart,
        newLines: hunk.oldLines,
        newStart: hunk.oldStart,
        lines: hunk.lines.map(function (l) {
          if (l.startsWith('-')) {
            return "+".concat(l.slice(1));
          }
          if (l.startsWith('+')) {
            return "-".concat(l.slice(1));
          }
          return l;
        })
      };
    })
  });
}

// See: http://code.google.com/p/google-diff-match-patch/wiki/API
function convertChangesToDMP(changes) {
  var ret = [],
    change,
    operation;
  for (var i = 0; i < changes.length; i++) {
    change = changes[i];
    if (change.added) {
      operation = 1;
    } else if (change.removed) {
      operation = -1;
    } else {
      operation = 0;
    }
    ret.push([operation, change.value]);
  }
  return ret;
}

function convertChangesToXML(changes) {
  var ret = [];
  for (var i = 0; i < changes.length; i++) {
    var change = changes[i];
    if (change.added) {
      ret.push('<ins>');
    } else if (change.removed) {
      ret.push('<del>');
    }
    ret.push(escapeHTML(change.value));
    if (change.added) {
      ret.push('</ins>');
    } else if (change.removed) {
      ret.push('</del>');
    }
  }
  return ret.join('');
}
function escapeHTML(s) {
  var n = s;
  n = n.replace(/&/g, '&amp;');
  n = n.replace(/</g, '&lt;');
  n = n.replace(/>/g, '&gt;');
  n = n.replace(/"/g, '&quot;');
  return n;
}

export { Diff, applyPatch, applyPatches, canonicalize, convertChangesToDMP, convertChangesToXML, createPatch, createTwoFilesPatch, diffArrays, diffChars, diffCss, diffJson, diffLines, diffSentences, diffTrimmedLines, diffWords, diffWordsWithSpace, formatPatch, merge, parsePatch, reversePatch, structuredPatch };