function processDiffs()

in client/src/components/versioned-storages/vs-actions/components/conflicts/utilities/analyze-conflicts.js [107:209]
101 lines of code
27 McCabe index (conditional complexity)

function processDiffs (contents, head, remote, mergeInProgress) {
  const list = parse(contents, mergeInProgress);
  const headRest = (head || []).slice();
  const remoteRest = (remote || []).slice();
  const modificationsAreTheSame = (a, b) => {
    return !!a && !!b && a.origin === b.origin && a.content === b.content;
  };
  const performInsertion = (line, ...branches) => {
    list.markLineAsInserted(line, ...branches);
  };
  const performDeletion = (line, content, ...branches) => {
    const inserted = list.insertLineBefore(line, content, {}, ...branches);
    if (inserted) {
      list.markLineAsRemoved(inserted, ...branches);
    }
  };
  const performModification = (line, modification, ...branches) => {
    if (modification.origin === '+') {
      performInsertion(line, ...branches);
    } else {
      performDeletion(line, modification.content, ...branches);
    }
  };
  while (headRest.length > 0 || remoteRest.length > 0) {
    const headModification = headRest[0];
    const remoteModification = remoteRest[0];
    let headLine, remoteLine;
    if (headModification) {
      if (headModification.origin === '+') {
        headLine = list.getLineAtIndex(HeadBranch, headModification.new_lineno);
      } else if (headModification.origin === '-') {
        headLine = list.getLineAtOriginalIndex(
          HeadBranch,
          headModification.old_lineno
        );
      }
    }
    if (remoteModification) {
      if (remoteModification.origin === '+') {
        remoteLine = list.getLineAtIndex(RemoteBranch, remoteModification.new_lineno);
      } else if (remoteModification.origin === '-') {
        remoteLine = list.getLineAtOriginalIndex(
          RemoteBranch,
          remoteModification.old_lineno
        );
      }
    }
    let sameModifications = false;
    let performHead = false;
    let performRemote = false;
    if (remoteLine && headLine) {
      sameModifications = remoteLine === headLine &&
        modificationsAreTheSame(headModification, remoteModification);
      const headIsParent = headLine.isParentFor(remoteLine);
      const remoteIsParent = headIsParent ? false : remoteLine.isParentFor(headLine);
      if (!headIsParent && !remoteIsParent) {
        // we're at conflicting branches; both modifications can be performed
        // (as they will be skipped)
        performHead = true;
        performRemote = true;
      } else {
        performHead = headIsParent;
        performRemote = remoteIsParent;
      }
    } else {
      performHead = !!headLine;
      performRemote = !!remoteLine;
    }
    if (sameModifications) {
      performModification(
        remoteLine,
        remoteModification,
        HeadBranch,
        RemoteBranch
      );
      headRest.splice(0, 1);
      remoteRest.splice(0, 1);
    } else {
      if (performHead) {
        performModification(
          headLine,
          headModification,
          HeadBranch
        );
        headRest.splice(0, 1);
      }
      if (performRemote) {
        performModification(remoteLine, remoteModification, RemoteBranch);
        remoteRest.splice(0, 1);
      }
      if (!performHead && !performRemote) {
        headRest.splice(0, 1);
        remoteRest.splice(0, 1);
      }
    }
  }
  prepareConflicts(list);
  list.preProcessLines(HeadBranch);
  list.preProcessLines(RemoteBranch);
  list.preProcessLines(Merged);
  prepareChanges(list);
  return list;
}