refactor(algo): cleanup utils (#630)

src/algorithms/utils.test.ts

@@ -47,9 +47,9 @@ describe("distanceBetweenPoints", () => {
 
 describe("extendPixelBounds", () => {
   test("is correct", () => {
-    const northEast = { x: 0, y: 0 } as google.maps.Point;
-    const southWest = { x: 0, y: 0 } as google.maps.Point;
-    expect(extendPixelBounds({ northEast, southWest }, 1)).toEqual({
+    const northEast = new google.maps.Point(0, 0);
+    const southWest = new google.maps.Point(0, 0);
+    expect(extendPixelBounds({ northEast, southWest }, 1)).toMatchObject({
       northEast: {
         x: 1,
         y: -1,
@@ -64,15 +64,11 @@ describe("extendPixelBounds", () => {
 
 describe("pixelBoundsToLatLngBounds", () => {
   test("is correct", () => {
-    const northEast = { x: 1, y: 1 } as google.maps.Point;
-    const southWest = { x: -1, y: -1 } as google.maps.Point;
+    const northEast = new google.maps.Point(1, 1);
+    const southWest = new google.maps.Point(-1, -1);
     const projection = new MapCanvasProjection();
-    const bounds = pixelBoundsToLatLngBounds(
-      { northEast, southWest },
-      projection
-    );
+    pixelBoundsToLatLngBounds({ northEast, southWest }, projection);
     expect(projection.fromDivPixelToLatLng).toHaveBeenCalledWith(northEast);
     expect(projection.fromDivPixelToLatLng).toHaveBeenCalledWith(southWest);
-    expect(bounds.extend).toHaveBeenCalledTimes(2);
   });
 });

src/algorithms/utils.ts

@@ -16,42 +16,53 @@
 
 import { MarkerUtils } from "../marker-utils";
 
+/**
+ * Returns the markers visible in a padded map viewport
+ *
+ * @param map
+ * @param mapCanvasProjection
+ * @param markers The list of marker to filter
+ * @param viewportPaddingPixels The padding in pixel
+ * @returns The list of markers in the padded viewport
+ */
 export const filterMarkersToPaddedViewport = (
   map: google.maps.Map,
   mapCanvasProjection: google.maps.MapCanvasProjection,
   markers: Marker[],
-  viewportPadding: number
+  viewportPaddingPixels: number
 ): Marker[] => {
   const extendedMapBounds = extendBoundsToPaddedViewport(
     map.getBounds(),
     mapCanvasProjection,
-    viewportPadding
+    viewportPaddingPixels
   );
   return markers.filter((marker) =>
     extendedMapBounds.contains(MarkerUtils.getPosition(marker))
   );
 };
 
 /**
- * Extends a bounds by a number of pixels in each direction.
+ * Extends a bounds by a number of pixels in each direction
  */
 export const extendBoundsToPaddedViewport = (
   bounds: google.maps.LatLngBounds,
   projection: google.maps.MapCanvasProjection,
-  pixels: number
+  numPixels: number
 ): google.maps.LatLngBounds => {
   const { northEast, southWest } = latLngBoundsToPixelBounds(
     bounds,
     projection
   );
   const extendedPixelBounds = extendPixelBounds(
     { northEast, southWest },
-    pixels
+    numPixels
   );
   return pixelBoundsToLatLngBounds(extendedPixelBounds, projection);
 };
 
 /**
+ * Returns the distance between 2 positions.
+ *
  * @hidden
  */
 export const distanceBetweenPoints = (
@@ -77,6 +88,8 @@ type PixelBounds = {
 };
 
 /**
+ * Converts a LatLng bound to pixels.
+ *
  * @hidden
  */
 const latLngBoundsToPixelBounds = (
@@ -90,17 +103,19 @@ const latLngBoundsToPixelBounds = (
 };
 
 /**
+ * Extends a pixel bounds by numPixels in all directions.
+ *
  * @hidden
  */
 export const extendPixelBounds = (
   { northEast, southWest }: PixelBounds,
-  pixels: number
+  numPixels: number
 ): PixelBounds => {
-  northEast.x += pixels;
-  northEast.y -= pixels;
+  northEast.x += numPixels;
+  northEast.y -= numPixels;
 
-  southWest.x -= pixels;
-  southWest.y += pixels;
+  southWest.x -= numPixels;
+  southWest.y += numPixels;
 
   return { northEast, southWest };
 };
@@ -112,8 +127,7 @@ export const pixelBoundsToLatLngBounds = (
   { northEast, southWest }: PixelBounds,
   projection: google.maps.MapCanvasProjection
 ): google.maps.LatLngBounds => {
-  const bounds = new google.maps.LatLngBounds();
-  bounds.extend(projection.fromDivPixelToLatLng(northEast));
-  bounds.extend(projection.fromDivPixelToLatLng(southWest));
-  return bounds;
+  const sw = projection.fromDivPixelToLatLng(southWest);
+  const ne = projection.fromDivPixelToLatLng(northEast);
+  return new google.maps.LatLngBounds(sw, ne);
 };