Resources now declare their required API versions, making GraphQL support a little cleaner

Sources/Buildkite/Buildkite.swift

@@ -101,12 +101,24 @@ public final class Buildkite {
 
 public extension Buildkite {
     func send<R: Resource & HasResponseBody>(_ resource: R, completion: @escaping (Result<Response<R.Content>, Error>) -> Void) {
-        let request = URLRequest(resource, configuration: configuration)
+        let request: URLRequest
+        do {
+            request = try URLRequest(resource, configuration: configuration)
+        } catch {
+            completion(.failure(error))
+            return
+        }
         transport.send(request: request, completion: handleContentfulResponse(completion: completion))
     }
     
     func send<R: Resource & Paginated>(_ resource: R, pageOptions: PageOptions? = nil, completion: @escaping (Result<Response<R.Content>, Error>) -> Void) {
-        let request = URLRequest(resource, configuration: configuration, pageOptions: pageOptions)
+        let request: URLRequest
+        do {
+            request = try URLRequest(resource, configuration: configuration, pageOptions: pageOptions)
+        } catch {
+            completion(.failure(error))
+            return
+        }
         transport.send(request: request, completion: handleContentfulResponse(completion: completion))
     }
     
@@ -133,7 +145,13 @@ public extension Buildkite {
     }
     
     func send<R: Resource>(_ resource: R, completion: @escaping (Result<Response<Void>, Error>) -> Void) {
-        let request = URLRequest(resource, configuration: configuration)
+        let request: URLRequest
+        do {
+            request = try URLRequest(resource, configuration: configuration)
+        } catch {
+            completion(.failure(error))
+            return
+        }
         transport.send(request: request, completion: handleEmptyResponse(completion: completion))
     }
     
@@ -157,7 +175,9 @@ import Combine
 @available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
 extension Buildkite {
     public func sendPublisher<R: Resource & HasResponseBody>(_ resource: R) -> AnyPublisher<Response<R.Content>, Error> {
-        transport.sendPublisher(request: URLRequest(resource, configuration: configuration))
+        Result { try URLRequest(resource, configuration: configuration) }
+            .publisher
+            .flatMap(transport.sendPublisher)
             .tryMap {
                 try self.checkResponseForIssues($0.response, data: $0.data)
                 let content = try self.decoder.decode(R.Content.self, from: $0.data)
@@ -167,7 +187,9 @@ extension Buildkite {
     }
     
     public func sendPublisher<R: Resource & HasResponseBody & Paginated>(_ resource: R, pageOptions: PageOptions? = nil) -> AnyPublisher<Response<R.Content>, Error> {
-        transport.sendPublisher(request: URLRequest(resource, configuration: configuration, pageOptions: pageOptions))
+        Result { try URLRequest(resource, configuration: configuration, pageOptions: pageOptions) }
+            .publisher
+            .flatMap(transport.sendPublisher)
             .tryMap {
                 try self.checkResponseForIssues($0.response, data: $0.data)
                 let content = try self.decoder.decode(R.Content.self, from: $0.data)
@@ -201,7 +223,9 @@ extension Buildkite {
     }
     
     public func sendPublisher<R: Resource>(_ resource: R) -> AnyPublisher<Response<Void>, Error> {
-        transport.sendPublisher(request: URLRequest(resource, configuration: configuration))
+        Result { try URLRequest(resource, configuration: configuration) }
+            .publisher
+            .flatMap(transport.sendPublisher)
             .tryMap {
                 try self.checkResponseForIssues($0.response)
                 return Response(content: (), response: $0.response)

Sources/Buildkite/Networking/APIVersion.swift

@@ -12,7 +12,7 @@ import Foundation
 import FoundationNetworking
 #endif
 
-public struct APIVersion {
+public struct APIVersion: Equatable {
     public enum REST {
         private static let baseURL = URL(string: "https://api.buildkite.com")!
         public static let v2 = APIVersion(baseURL: baseURL, version: "v2")

Sources/Buildkite/Networking/Configuration.swift

@@ -12,18 +12,18 @@ import Foundation
 import FoundationNetworking
 #endif
 
-let libraryVersion = "0.0.1"
-
 public struct Configuration {
-    public let userAgent = "buildkite-swift/\(libraryVersion)"
+    public let userAgent = "buildkite-swift"
     public var version: APIVersion
+    public var graphQLVersion: APIVersion
 
     public static var `default`: Configuration {
-        .init(version: APIVersion.REST.v2)
+        .init(version: APIVersion.REST.v2, graphQLVersion: APIVersion.GraphQL.v1)
     }
 
-    public init(version: APIVersion) {
+    public init(version: APIVersion = APIVersion.REST.v2, graphQLVersion: APIVersion = APIVersion.GraphQL.v1) {
         self.version = version
+        self.graphQLVersion = graphQLVersion
     }
 
     var token: String?

Sources/Buildkite/Networking/Resource.swift

@@ -14,11 +14,16 @@ import FoundationNetworking
 
 public protocol Resource {
     associatedtype Content
+    var version: APIVersion { get }
     var path: String { get }
     func transformRequest(_ request: inout URLRequest)
 }
 
 extension Resource {
+    public var version: APIVersion {
+        APIVersion.REST.v2
+    }
+    
     public func transformRequest(_ request: inout URLRequest) {}
 }
 
@@ -34,8 +39,14 @@ public protocol HasResponseBody {
 public protocol Paginated: HasResponseBody {}
 
 extension URLRequest {
-    init<R: Resource>(_ resource: R, configuration: Configuration) {
+    init<R: Resource>(_ resource: R, configuration: Configuration) throws {
-        let url = configuration.version.url(for: resource.path)
+        let version = resource.version
+        guard version == configuration.version
+            || version == configuration.graphQLVersion else {
+                throw ResponseError.incompatibleVersion
+        }
+        let url = version.url(for: resource.path)
+        
         var request = URLRequest(url: url)
         configuration.transformRequest(&request)
         resource.transformRequest(&request)
@@ -43,12 +54,12 @@ extension URLRequest {
     }
 
     init<R: Resource & HasRequestBody>(_ resource: R, configuration: Configuration, encoder: JSONEncoder) throws {
-        self.init(resource, configuration: configuration)
+        try self.init(resource, configuration: configuration)
         httpBody = try encoder.encode(resource.body)
     }
 
-    init<R: Resource & Paginated>(_ resource: R, configuration: Configuration, pageOptions: PageOptions? = nil) {
+    init<R: Resource & Paginated>(_ resource: R, configuration: Configuration, pageOptions: PageOptions? = nil) throws {
-        self.init(resource, configuration: configuration)
+        try self.init(resource, configuration: configuration)
         if let options = pageOptions {
             appendPageOptions(options)
         }

Sources/Buildkite/Networking/Response.swift

@@ -13,6 +13,7 @@ import FoundationNetworking
 #endif
 
 enum ResponseError: Error {
+    case incompatibleVersion
     case missingResponse
     case unexpectedlyNoContent
 }

Sources/Buildkite/Resources/GraphQL.swift

@@ -40,6 +40,10 @@ public struct GraphQL<T: Codable>: Resource, HasResponseBody, HasRequestBody {
     
     public var body: Body
     
+    public var version: APIVersion {
+        APIVersion.GraphQL.v1
+    }
+    
     public let path = ""
 
     public init(rawQuery query: String, variables: [String: JSONValue] = [:]) {
@@ -47,7 +51,6 @@ public struct GraphQL<T: Codable>: Resource, HasResponseBody, HasRequestBody {
     }
     
     public func transformRequest(_ request: inout URLRequest) {
-        request.url = APIVersion.GraphQL.v1.url(for: path)
         request.httpMethod = "POST"
     }
 }