export function combineChange()

in src/compat/firestore/collection/changes.ts [95:125]

• 28 lines of code
• 11 McCabe index (conditional complexity)

export function combineChange<T>(combined: DocumentChange<T>[], change: DocumentChange<T>): DocumentChange<T>[] {
  switch (change.type) {
    case 'added':
      if (combined[change.newIndex] && combined[change.newIndex].doc.ref.isEqual(change.doc.ref)) {
        // Not sure why the duplicates are getting fired
      } else {
        return sliceAndSplice(combined, change.newIndex, 0, change);
      }
      break;
    case 'modified':
      if (combined[change.oldIndex] == null || combined[change.oldIndex].doc.ref.isEqual(change.doc.ref)) {
        // When an item changes position we first remove it
        // and then add it's new position
        if (change.oldIndex !== change.newIndex) {
          const copiedArray = combined.slice();
          copiedArray.splice(change.oldIndex, 1);
          copiedArray.splice(change.newIndex, 0, change);
          return copiedArray;
        } else {
          return sliceAndSplice(combined, change.newIndex, 1, change);
        }
      }
      break;
    case 'removed':
      if (combined[change.oldIndex] && combined[change.oldIndex].doc.ref.isEqual(change.doc.ref)) {
        return sliceAndSplice(combined, change.oldIndex, 1);
      }
      break;
  }
  return combined;
}