All, no clean code

Polygon.js

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+import * as turf from "@turf/turf";
+
+/**
+ * Converts an array of canvas-compatible points into a Turf.js Polygon.
+ *
+ * @param {{x: number, y: number}[]} points - Array of points with x and y properties.
+ *
+ * @returns {import('@turf/turf').Feature<import('@turf/turf').Polygon> | null} A Turf.js Polygon feature, or null if input is invalid.
+ */
+export function toTurfPolygon(points) {
+    if (!points || points.length < 3) {
+        console.error("Invalid input for polygon:", points);
+        return null;
+    }
+
+    const coords = points.map(p => [p.y, p.x]);
+    coords.push(coords[0]);
+    return turf.polygon([coords]);
+}
+
+/**
+ * Merges two polygons (in canvas format) into a single Turf.js polygon using turf.union.
+ *
+ * @param {{x: number, y: number}[]} polygonA - First polygon (array of points).
+ * @param {{x: number, y: number}[]} polygonB - Second polygon (array of points).
+ *
+ * @returns {import('@turf/turf').Feature<import('@turf/turf').Polygon> | null} A merged Turf.js polygon, or null on failure.
+ */
+export function mergeTurfPolygons(polygonA, polygonB) {
+    const turfPolygonA = toTurfPolygon(polygonA);
+    const turfPolygonB = toTurfPolygon(polygonB);
+
+    return turf.union(turf.featureCollection([turfPolygonA, turfPolygonB]));
+}
+
+/**
+ * Adds a new polygon to an existing merged Turf.js polygon.
+ *
+ * @param {import('@turf/turf').Feature<import('@turf/turf').Polygon>} polygonA - Existing merged Turf.js polygon.
+ * @param {{x: number, y: number}[]} polygonB - New polygon in canvas point format to add to the merge.
+ *
+ * @returns {import('@turf/turf').Feature<import('@turf/turf').Polygon>} Updated merged Turf.js polygon.
+ */
+export function addTurfPolygonToMerge(polygonA, polygonB) {
+    const testB = toTurfPolygon(polygonB);
+    return turf.union(turf.featureCollection([polygonA, testB]));
+}
+
+/**
+ * @param {{x: number, y: number}[][]} polygons
+ * @returns {Feature<Polygon | MultiPolygon, GeoJsonProperties>}
+ */
+
+export function mergePolygons(polygons) {
+
+    if (!polygons || polygons.length === 0)
+        return undefined;
+
+    if (polygons.length === 1)
+        return toTurfPolygon(polygons[0]);
+
+    return turf.union(turf.featureCollection(polygons.map(p => toTurfPolygon(p))));
+}
+
+/**
+ *
+ * @param {Array<Feature<Polygon | MultiPolygon, GeoJsonProperties>>|undefined} features
+ * @returns {Feature<Polygon | MultiPolygon, GeoJsonProperties>|undefined|*}
+ */
+export function mergePolygonFeatures(features) {
+
+    if (!features || features.length === 0)
+        return undefined;
+
+    if (features.length === 1)
+        return features[0];
+
+    return turf.union(turf.featureCollection(features));
+}