parse-conflict-json

Parse a JSON string that has git merge conflicts, resolving if possible.

If the JSON is valid, it just does JSON.parse as normal.

If either side of the conflict is invalid JSON, then an error is thrown for
that.

USAGE

 // after a git merge that left some conflicts there
const data = fs.readFileSync('package-lock.json', 'utf8')

// reviverFunction is passed to JSON.parse as the reviver function
// preference defaults to 'ours', set to 'theirs' to prefer the other
// side's changes.
const parsed = parseConflictJson(data, reviverFunction, preference)

// returns true if the data looks like a conflicted diff file
parsed.isDiff(data)

Algorithm

If prefer is set to theirs, then the vaules of theirs and ours are
switched in the resolver function. (Ie, we'll apply their changes on top
of our object, rather than the other way around.)

• Parse the conflicted file into 3 pieces: ours, theirs, and parent

• Get the diff from parent
  to ours.

• Apply each change of
  that diff to theirs.

  If any change in the diff set cannot be applied (ie, because they
  changed an object into a non-object and we changed a field on that
  object), then replace the object at the specified path with the object
  at the path in ours.