Responses to code review / pull request:

Renamed several methods to use identifier `coordinate` instead of `point`.
Made `BoundingBox` a `Codable` `struct`.
Removed several instances of an explict usage of `self`.

Sources/Turf/BoundingBox.swift

@@ -3,30 +3,38 @@ import Foundation
 import CoreLocation
 #endif
 
-public class BoundingBox {
+public struct BoundingBox: Codable {
 
-    public init?(points: [CLLocationCoordinate2D]?) {
-        guard points?.count ?? 0 > 0 else {
+    public init?(from coordinates: [CLLocationCoordinate2D]?) {
+        guard coordinates?.count ?? 0 > 0 else {
             return nil
         }
-        (minLat, maxLat, minLon, maxLon) = points!
+        let (minLat, maxLat, minLon, maxLon) = coordinates!
             .reduce((minLat: 0, maxLat: 0, minLon: 0, maxLon: 0)) { (result, coordinate) -> (minLat: Double, maxLat: Double, minLon: Double, maxLon: Double) in
                 let minLat = min(coordinate.latitude, result.0)
                 let maxLat = max(coordinate.latitude, result.1)
                 let minLon = min(coordinate.longitude, result.2)
                 let maxLon = max(coordinate.longitude, result.3)
                 return (minLat: minLat, maxLat: maxLat, minLon: minLon, maxLon: maxLon)
         }
+        northWest = CLLocationCoordinate2D(latitude: maxLat, longitude: minLon)
+        southEast = CLLocationCoordinate2D(latitude: minLat, longitude: maxLon)
     }
 
-    public func contains(point: CLLocationCoordinate2D) -> Bool {
-        return minLat < point.latitude && maxLat > point.latitude && minLon < point.longitude && maxLon > point.longitude
+    public init(_ northWest: CLLocationCoordinate2D, _ southEast: CLLocationCoordinate2D) {
+        self.northWest = northWest
+        self.southEast = southEast
+    }
+
+    public func contains(_ coordinate: CLLocationCoordinate2D) -> Bool {
+        return southEast.latitude < coordinate.latitude
+            && northWest.latitude > coordinate.latitude
+            && northWest.longitude < coordinate.longitude
+            && southEast.longitude > coordinate.longitude
     }
 
     // MARK: - Private
 
-    let minLat: Double
-    let maxLat: Double
-    let minLon: Double
-    let maxLon: Double
+    let northWest: CLLocationCoordinate2D
+    let southEast: CLLocationCoordinate2D
 }

Sources/Turf/Polygon.swift

@@ -63,23 +63,23 @@ extension Polygon {
 extension Polygon {
 
     /**
-     * Determines if the given point falls within the polygon and outside of its interior rings.
-     * The optional parameter `ignoreBoundary` will result in the method returning true if the given point
+     * Determines if the given coordinate falls within the polygon and outside of its interior rings.
+     * The optional parameter `ignoreBoundary` will result in the method returning true if the given coordinate
      * lies on the boundary line of the polygon or its interior rings.
      *
      * Ported from: https://github.com/Turfjs/turf/blob/e53677b0931da9e38bb947da448ee7404adc369d/packages/turf-boolean-point-in-polygon/index.ts#L31-L75
      */
-    public func contains(point: CLLocationCoordinate2D, ignoreBoundary: Bool = false) -> Bool {
-        let bbox = BoundingBox(points: self.coordinates.first)
-        guard bbox?.contains(point: point) ?? false else {
+    public func contains(_ coordinate: CLLocationCoordinate2D, ignoreBoundary: Bool = false) -> Bool {
+        let bbox = BoundingBox(from: coordinates.first)
+        guard bbox?.contains(coordinate) ?? false else {
             return false
         }
-        guard self.outerRing.contains(point: point, ignoreBoundary: ignoreBoundary) else {
+        guard outerRing.contains(coordinate, ignoreBoundary: ignoreBoundary) else {
             return false
         }
         if let innerRings = innerRings {
             for ring in innerRings {
-                if ring.contains(point: point, ignoreBoundary: ignoreBoundary) {
+                if ring.contains(coordinate, ignoreBoundary: ignoreBoundary) {
                     return false
                 }
             }

Sources/Turf/Ring.swift

@@ -62,7 +62,7 @@ extension Ring {
      *
      * Ported from: https://github.com/Turfjs/turf/blob/e53677b0931da9e38bb947da448ee7404adc369d/packages/turf-boolean-point-in-polygon/index.ts#L77-L108
      */
-    public func contains(point: CLLocationCoordinate2D, ignoreBoundary: Bool = false) -> Bool {
+    public func contains(_ coordinate: CLLocationCoordinate2D, ignoreBoundary: Bool = false) -> Bool {
         var ring: ArraySlice<CLLocationCoordinate2D>!
         var isInside = false
         if coordinates.first == coordinates.last {
@@ -78,13 +78,13 @@ extension Ring {
             let yi = ring[i].latitude
             let xj = ring[j].longitude
             let yj = ring[j].latitude
-            let onBoundary = (point.latitude * (xi - xj) + yi * (xj - point.longitude) + yj * (point.longitude - xi) == 0) &&
-                ((xi - point.longitude) * (xj - point.longitude) <= 0) && ((yi - point.latitude) * (yj - point.latitude) <= 0)
+            let onBoundary = (coordinate.latitude * (xi - xj) + yi * (xj - coordinate.longitude) + yj * (coordinate.longitude - xi) == 0) &&
+                ((xi - coordinate.longitude) * (xj - coordinate.longitude) <= 0) && ((yi - coordinate.latitude) * (yj - coordinate.latitude) <= 0)
             if onBoundary {
                 return !ignoreBoundary
             }
-            let intersect = ((yi > point.latitude) != (yj > point.latitude)) &&
-                (point.longitude < (xj - xi) * (point.latitude - yi) / (yj - yi) + xi);
+            let intersect = ((yi > coordinate.latitude) != (yj > coordinate.latitude)) &&
+                (coordinate.longitude < (xj - xi) * (coordinate.latitude - yi) / (yj - yi) + xi);
             if (intersect) {
                 isInside = !isInside;
             }

Tests/TurfTests/PolygonTests.swift

@@ -38,7 +38,7 @@ class PolygonTests: XCTestCase {
             CLLocationCoordinate2D(latitude: 41, longitude: -72),
             CLLocationCoordinate2D(latitude: 41, longitude: -81),
             ]])
-        XCTAssertTrue(polygon.contains(point: coordinate))
+        XCTAssertTrue(polygon.contains(coordinate))
     }
 
     func testPolygonDoesNotContain() {
@@ -50,7 +50,7 @@ class PolygonTests: XCTestCase {
             CLLocationCoordinate2D(latitude: 41, longitude: -42),
             CLLocationCoordinate2D(latitude: 41, longitude: -51),
             ]])
-        XCTAssertFalse(polygon.contains(point: coordinate))
+        XCTAssertFalse(polygon.contains(coordinate))
     }
 
     func testPolygonDoesNotContainWithHole() {
@@ -71,6 +71,6 @@ class PolygonTests: XCTestCase {
                 CLLocationCoordinate2D(latitude: 43, longitude: -76),
             ],
         ])
-        XCTAssertFalse(polygon.contains(point: coordinate))
+        XCTAssertFalse(polygon.contains(coordinate))
     }
 }