@seasketch/geoprocessing/src/helpers/removeHoles.ts

Geoprocessing and reporting framework for SeaSketch 2.0

import {
  Sketch,
  SketchCollection,
  MultiPolygon,
  Polygon,
} from "../types/index.js";
import { isMultiPolygonSketch, isPolygonSketch } from "./sketch.js";

export function removeSketchPolygonHoles(
  sketch: Sketch<Polygon | MultiPolygon>,
) {
  const newSk: Sketch<Polygon | MultiPolygon> = { ...sketch };
  if (isMultiPolygonSketch(sketch)) {
    newSk.geometry.coordinates = newSk.geometry.coordinates.map(
      (polyCoords) => {
        return [polyCoords[0]];
      },
    );
  } else if (isPolygonSketch(sketch)) {
    newSk.geometry.coordinates = [sketch.geometry.coordinates[0]];
  }
  return newSk;
}

export function removeSketchCollPolygonHoles(
  sketchColl: SketchCollection<Polygon | MultiPolygon>,
) {
  return sketchColl.features.map((sk) => removeSketchPolygonHoles(sk));
}