function immutablyRemovePosition()

in modules/edit-modes/src/lib/immutable-feature-collection.ts [268:312]

• 38 lines of code
• 9 McCabe index (conditional complexity)

function immutablyRemovePosition(
  coordinates: any,
  positionIndexes: number[] | null | undefined,
  isPolygonal: boolean
): any {
  if (!positionIndexes) {
    return coordinates;
  }
  if (positionIndexes.length === 0) {
    throw Error('Must specify the index of the position to remove');
  }
  if (positionIndexes.length === 1) {
    const updated = [
      ...coordinates.slice(0, positionIndexes[0]),
      ...coordinates.slice(positionIndexes[0] + 1),
    ];

    if (
      isPolygonal &&
      (positionIndexes[0] === 0 || positionIndexes[0] === coordinates.length - 1)
    ) {
      // for polygons, the first point is repeated at the end of the array
      // so, if the first/last coordinate is to be removed, coordinates[1] will be the new first/last coordinate
      if (positionIndexes[0] === 0) {
        // change the last to be the same as the first
        updated[updated.length - 1] = updated[0];
      } else if (positionIndexes[0] === coordinates.length - 1) {
        // change the first to be the same as the last
        updated[0] = updated[updated.length - 1];
      }
    }
    return updated;
  }

  // recursively update inner array
  return [
    ...coordinates.slice(0, positionIndexes[0]),
    immutablyRemovePosition(
      coordinates[positionIndexes[0]],
      positionIndexes.slice(1, positionIndexes.length),
      isPolygonal
    ),
    ...coordinates.slice(positionIndexes[0] + 1),
  ];
}