Fix Neighbourhood decoding with null url_force (#60)

Sources/PoliceAPI/Models/Neighbourhood.swift

@@ -17,7 +17,11 @@ public struct Neighbourhood: Identifiable, Decodable, Equatable {
     }
     /// URL for the neighbourhood on the Force's website.
     public var policeForceWebsite: URL? {
-        URL(string: policeForceWebsiteString)
+        guard let policeForceWebsiteString else {
+            return nil
+        }
+
+        return URL(string: policeForceWebsiteString)
     }
     /// An introduction message for the neighbourhood.
     public let welcomeMessage: String?
@@ -38,7 +42,7 @@ public struct Neighbourhood: Identifiable, Decodable, Equatable {
     /// Links.
     public let links: [Link]
 
-    private let policeForceWebsiteString: String
+    private let policeForceWebsiteString: String?
     private let nameString: String
     private let descriptionString: String?
     private let populationString: String
@@ -62,7 +66,7 @@ public struct Neighbourhood: Identifiable, Decodable, Equatable {
         self.id = id
         self.nameString = name
         self.descriptionString = description
-        self.policeForceWebsiteString = policeForceWebsite?.absoluteString ?? ""
+        self.policeForceWebsiteString = policeForceWebsite?.absoluteString
         self.welcomeMessage = welcomeMessage
         self.populationString = String(population)
         self.contactDetails = contactDetails

Tests/PoliceAPITests/Models/NeighbourhoodTests.swift

@@ -49,4 +49,11 @@ final class NeighbourhoodTests: XCTestCase {
         XCTAssertNil(result)
     }
 
+    func testPoliceForceWebsiteWhenNull() throws {
+        let result = try JSONDecoder.policeDataAPI
+            .decode(Neighbourhood.self, fromResource: "neighbourhood-null-force-url").policeForceWebsite
+
+        XCTAssertNil(result)
+    }
+
 }

Tests/PoliceAPITests/Resources/json/neighbourhood-null-force-url.json

@@ -0,0 +1,14 @@
+{
+    "url_force": null,
+    "contact_details": {},
+    "name": "Banks & Hesketh",
+    "links": [],
+    "centre": {
+        "latitude": "52.6389",
+        "longitude": "-1.13619"
+    },
+    "locations": [],
+    "description": "Some & description",
+    "id": "AB12",
+    "population": "1000"
+}