feat: bypass body serialization if body type is data

Sources/NClient/Endpoint.swift

@@ -30,6 +30,8 @@ public protocol Endpoint {
     /// The HTTP method of the endpoint.
     var method: HTTP.Method { get }
 
+    var contentType: HTTP.MIMEType { get }
+
     /// Constructs the URL components for the endpoint given the parameters.
     func url(parameters: Parameters) -> URLComponents
 
@@ -43,6 +45,9 @@ public protocol Endpoint {
 public extension Endpoint {
     /// The default HTTP method for the endpoint is `GET`.
     var method: HTTP.Method { .GET }
+
+    /// The default Content-Type  for the endpoint is `application/json`.
+    var contentType: HTTP.MIMEType { .json }
 }
 
 // MARK: Request creation
@@ -73,7 +78,7 @@ public extension Endpoint {
 
         var request = URLRequest(url: url.absoluteURL)
         request.httpMethod = method.rawValue
-        request.setHeader(.accept, value: HTTP.MIMEType.json)
+        request.setHeader(.accept, value: HTTP.MIMEType.json.rawValue)
         try serializeBody(requestBody, into: &request)
 
         return request
@@ -90,12 +95,20 @@ public extension Endpoint where RequestBody == Empty {
 public extension Endpoint where RequestBody: Encodable {
     /// Serializes an encodable request body as JSON.
     func serializeBody(_ body: RequestBody, into request: inout URLRequest) throws {
-        request.setHeader(.contentType, value: HTTP.MIMEType.json)
+        request.setHeader(.contentType, value: contentType.rawValue)
         let data = try JSONEncoder().encode(body)
         request.httpBody = data
     }
 }
 
+public extension Endpoint where RequestBody == Data {
+    /// Bypass serialization if request body is already of Data type
+    func serializeBody(_ body: RequestBody, into request: inout URLRequest) throws {
+        request.setHeader(.contentType, value: contentType.rawValue)
+        request.httpBody = body
+    }
+}
+
 // MARK: Deserialize
 
 public extension Endpoint where ResponseBody == Empty {

Sources/NClient/HTTP.swift

@@ -18,16 +18,14 @@ public enum HTTP {
     struct HeaderName: RawRepresentable {
         let rawValue: String
     }
-}
 
-extension HTTP {
-    /// Represents common MIME types used in HTTP requests and responses.
-    enum MIMEType {
-        /// JSON data.
-        static let json = "application/json"
+    /// Supported MIME types
+    public struct MIMEType: RawRepresentable {
+        public let rawValue: String
 
-        /// URL-encoded form data.
-        static let formUrlEncoded = "application/x-www-form-urlencoded"
+        public init(rawValue: String) {
+            self.rawValue = rawValue
+        }
     }
 }
 
@@ -45,6 +43,17 @@ extension HTTP.HeaderName {
     static let contentType = HTTP.HeaderName("Content-Type")
 }
 
+public extension HTTP.MIMEType {
+    /// JSON data.
+    static let json = HTTP.MIMEType(rawValue: "application/json")
+
+    /// URL-encoded form data.
+    static let formUrlEncoded = HTTP.MIMEType(rawValue: "application/x-www-form-urlencoded")
+
+    /// MP4
+    static let mp4 = HTTP.MIMEType(rawValue: "audio/mp4")
+}
+
 extension URLRequest {
     mutating func setHeader(_ name: HTTP.HeaderName, value: String) {
         setValue(value, forHTTPHeaderField: name.rawValue)

Tests/NClientTests/Unit/APIClientTests.swift

@@ -35,7 +35,7 @@ final class APIClientTests: XCTestCase {
             result: .success(
                 .init(
                     statusCode: 200,
-                    headers: [HTTP.HeaderName.contentType.rawValue: HTTP.MIMEType.json],
+                    headers: [HTTP.HeaderName.contentType.rawValue: HTTP.MIMEType.json.rawValue],
                     data: mockResponseData
                 )
             )

Tests/NClientTests/Unit/EndpointTests.swift

@@ -20,7 +20,7 @@ final class EndpointTests: XCTestCase {
         XCTAssertEqual(request.url?.absoluteString, "https://example.com/path")
         XCTAssertEqual(request.httpMethod, HTTP.Method.GET.rawValue)
 
-        XCTAssertEqual(request.value(forHTTPHeaderField: HTTP.HeaderName.accept.rawValue), HTTP.MIMEType.json)
+        XCTAssertEqual(request.value(forHTTPHeaderField: HTTP.HeaderName.accept.rawValue), HTTP.MIMEType.json.rawValue)
         XCTAssertNil(request.value(forHTTPHeaderField: HTTP.HeaderName.contentType.rawValue))
 
         XCTAssertNil(request.httpBody)
@@ -48,14 +48,32 @@ final class EndpointTests: XCTestCase {
         XCTAssertEqual(request.url?.absoluteString, "https://example.com/path")
         XCTAssertEqual(request.httpMethod, HTTP.Method.POST.rawValue)
 
-        XCTAssertEqual(request.value(forHTTPHeaderField: HTTP.HeaderName.accept.rawValue), HTTP.MIMEType.json)
-        XCTAssertEqual(request.value(forHTTPHeaderField: HTTP.HeaderName.contentType.rawValue), HTTP.MIMEType.json)
+        XCTAssertEqual(request.value(forHTTPHeaderField: HTTP.HeaderName.accept.rawValue), HTTP.MIMEType.json.rawValue)
+        XCTAssertEqual(request.value(forHTTPHeaderField: HTTP.HeaderName.contentType.rawValue), HTTP.MIMEType.json.rawValue)
 
         let bodyData = try JSONEncoder().encode(mockRequestBody)
         XCTAssertNotNil(request.httpBody)
         XCTAssertEqual(request.httpBody, bodyData)
     }
 
+    func testEndpointWithRawRequestBody() throws {
+        let endpoint = MockEndpointWithRawResponseBody()
+        let request = try endpoint.request(
+            baseUrl: mockBaseUrl,
+            parameters: .empty,
+            requestBody: try XCTUnwrap(mockMessage.data(using: .utf8))
+        )
+
+        XCTAssertEqual(request.url?.absoluteString, "https://example.com/path")
+        XCTAssertEqual(request.httpMethod, HTTP.Method.POST.rawValue)
+
+        XCTAssertEqual(request.value(forHTTPHeaderField: HTTP.HeaderName.accept.rawValue), HTTP.MIMEType.json.rawValue)
+        XCTAssertEqual(request.value(forHTTPHeaderField: HTTP.HeaderName.contentType.rawValue), HTTP.MIMEType.mp4.rawValue)
+
+        let requestBody = try XCTUnwrap(request.httpBody)
+        XCTAssertEqual(String(data: requestBody, encoding: .utf8), mockMessage)
+    }
+
     // MARK: Deserialize
 
     func testDeserializeEmptyBody() throws {
@@ -140,3 +158,19 @@ private struct MockEndpointWithResponseBody: Endpoint {
         .init(path: mockPath)
     }
 }
+
+private struct MockEndpointWithRawResponseBody: Endpoint {
+    typealias RequestBody = Data
+
+    var method: HTTP.Method {
+        .POST
+    }
+
+    var contentType: HTTP.MIMEType {
+        .mp4
+    }
+
+    func url(parameters: Parameters) -> URLComponents {
+        .init(path: mockPath)
+    }
+}