Merge pull request #230 from gormster/DataParserAssociatedTypes

Data parser associated types

Author: ishkawa

.gitignore

@@ -60,3 +60,5 @@ Carthage/Build
 
 fastlane/report.xml
 fastlane/screenshots
+
+.DS_Store

Sources/APIKit/DataParser/DataParser.swift

@@ -2,10 +2,12 @@ import Foundation
 
 /// `DataParser` protocol provides inteface to parse HTTP response body and to state Content-Type to accept.
 public protocol DataParser {
+    associatedtype Parsed
+
     /// Value for `Accept` header field of HTTP request.
     var contentType: String? { get }
 
     /// Return `Any` that expresses structure of response such as JSON and XML.
     /// - Throws: `Error` when parser encountered invalid format data.
-    func parse(data: Data) throws -> Any
+    func parse(data: Data) throws -> Parsed
 }

Sources/APIKit/Request.swift

@@ -11,6 +11,7 @@ import Result
 public protocol Request {
     /// The response type associated with the request type.
     associatedtype Response
+    associatedtype Parser: DataParser
 
     /// The base URL.
     var baseURL: URL { get }
@@ -41,7 +42,7 @@ public protocol Request {
     var headerFields: [String: String] { get }
 
     /// The parser object that states `Content-Type` to accept and parses response body.
-    var dataParser: DataParser { get }
+    var dataParser: Parser { get }
 
     /// Intercepts `URLRequest` which is created by `Request.buildURLRequest()`. If an error is
     /// thrown in this method, the result of `Session.send()` turns `.failure(.requestError(error))`.
@@ -53,15 +54,16 @@ public protocol Request {
     /// The default implementation of this method is provided to throw `RequestError.unacceptableStatusCode`
     /// if the HTTP status code is not in `200..<300`.
     /// - Throws: `Error`
-    func intercept(object: Any, urlResponse: HTTPURLResponse) throws -> Any
+    func intercept(object: Parser.Parsed, urlResponse: HTTPURLResponse) throws -> Parser.Parsed
 
     /// Build `Response` instance from raw response object. This method is called after
     /// `intercept(object:urlResponse:)` if it does not throw any error.
     /// - Throws: `Error`
-    func response(from object: Any, urlResponse: HTTPURLResponse) throws -> Response
+    func response(from object: Parser.Parsed, urlResponse: HTTPURLResponse) throws -> Response
 }
 
 public extension Request {
+
     public var parameters: Any? {
         return nil
     }
@@ -86,15 +88,11 @@ public extension Request {
         return [:]
     }
 
-    public var dataParser: DataParser {
-        return JSONDataParser(readingOptions: [])
-    }
-
     public func intercept(urlRequest: URLRequest) throws -> URLRequest {
         return urlRequest
     }
 
-    public func intercept(object: Any, urlResponse: HTTPURLResponse) throws -> Any {
+    public func intercept(object: Parser.Parsed, urlResponse: HTTPURLResponse) throws -> Parser.Parsed {
         guard 200..<300 ~= urlResponse.statusCode else {
             throw ResponseError.unacceptableStatusCode(urlResponse.statusCode)
         }
@@ -146,3 +144,13 @@ public extension Request {
         return try response(from: passedObject, urlResponse: urlResponse)
     }
 }
+
+public protocol JSONRequest: Request {}
+
+public extension JSONRequest {
+
+    public var dataParser: JSONDataParser {
+        return JSONDataParser(readingOptions: [])
+    }
+
+}

Tests/APIKitTests/SessionTests.swift

@@ -175,7 +175,7 @@ class SessionTests: XCTestCase {
         waitForExpectations(timeout: 1.0, handler: nil)
     }
 
-    struct AnotherTestRequest: Request {
+    struct AnotherTestRequest: JSONRequest {
         typealias Response = Void
 
         var baseURL: URL {

Tests/APIKitTests/TestComponents/TestRequest.swift

@@ -1,7 +1,7 @@
 import Foundation
 import APIKit
 
-struct TestRequest: Request {
+struct TestRequest: JSONRequest {
     var absoluteURL: URL? {
         let urlRequest = try? buildURLRequest()
         return urlRequest?.url