refactor(s2): various small fixes

Author: missinglink

s2/CellUnion.ts

@@ -43,8 +43,7 @@ export class CellUnion extends Array<CellID> implements Region {
    * @category Constructors
    */
   static fromUnion(...cellUnions: CellUnion[]): CellUnion {
-    const cu = new CellUnion()
-    for (const cellUnion of cellUnions) cu.push(...cellUnion)
+    const cu = new CellUnion(...cellUnions.flat(1))
     cu.normalize()
     return cu
   }

s2/LatLng.ts

@@ -27,7 +27,7 @@ export class LatLng {
    * Returns a LatLng for the coordinates given in degrees.
    * @category Constructors
    */
-  static fromDegrees(lat: Angle, lng: Angle): LatLng {
+  static fromDegrees(lat: number, lng: number): LatLng {
     return new LatLng(lat * DEGREE, lng * DEGREE)
   }
 

s2/Point.ts

@@ -223,7 +223,7 @@ export class Point implements Region {
 
     for (let i = 0; i < numVertices; i++) {
       const angle = i * radianStep
-      const p = Point.fromVector(new Vector(r * Math.cos(angle), r * Math.sin(angle), z))
+      const p = new Point(r * Math.cos(angle), r * Math.sin(angle), z)
       vertices.push(Point.fromVector(fromFrame(frame, p).vector.normalize()))
     }
 

s2/cellid.ts

@@ -633,8 +633,6 @@ export const prevWrap = (ci: CellID): CellID => {
 
 /**
  * Returns the level of the common ancestor of the two S2 CellIDs.
- * @param other The other CellID to compare with.
- * @returns A tuple where the first element is the level and the second element is a boolean indicating success.
  */
 export const commonAncestorLevel = (ci: CellID, other: CellID): [number, boolean] => {
   let bits = ci ^ other