feat(session): Simplify config API (#32)

Author: pjechris

README.md

@@ -52,11 +52,7 @@ You can also use a `Session` object. [`Session`](https://pjechris.github.io/Simp
 
 ```swift
 
-let session = Session(
-  baseURL: URL(string: "https://github.com")!,
-  encoder: JSONEncoder(),
-  decoder: JSONDecoder()
-)
+let session = Session(baseURL: URL(string: "https://github.com")!)
 
 try await session.response(for: .login(UserBody(username: "pjechris", password: "MyPassword")))
 
@@ -65,9 +61,24 @@ try await session.response(for: .login(UserBody(username: "pjechris", password:
 A few words about Session:
 
 - `baseURL` will be prepended to all call paths
-- You can skip encoder and decoder if you use JSON
+- By default JSON is used for both encoding and decoding, so you don't have to configure anything for JSON APIs
 - You can provide a custom `URLSession` instance if ever needed
 
+### Customizing encoders/decoders
+
+Encoders and decoders are configured per content type through a `SessionConfiguration`. Pass a `ContentDataCodersConfiguration` to register the coders you need:
+
+```swift
+let session = Session(
+  baseURL: URL(string: "https://github.com")!,
+  configuration: SessionConfiguration(
+    data: ContentDataCodersConfiguration()
+      .encoding(.json, with: JSONEncoder())
+      .decoding(.json, with: JSONDecoder())
+  )
+)
+```
+
 ## Send a body
 
 Request support two body types:

Sources/SimpleHTTP/ContentData/ContentDataCoderConfiguration.swift

@@ -0,0 +1,53 @@
+import Foundation
+
+public typealias ContentDataEncodersConfiguration = [HTTPContentType: ContentDataEncoder]
+public typealias ContentDataDecodersConfiguration = [HTTPContentType: ContentDataDecoder]
+
+/// Defines the list of encoders and decoders to use.
+public struct ContentDataCodersConfiguration {
+    public var encoders: ContentDataEncodersConfiguration
+    public var decoders: ContentDataDecodersConfiguration
+    public let defaultType: HTTPContentType
+
+    public init(
+        default: HTTPContentType,
+        encoders: ContentDataEncodersConfiguration,
+        decoders: ContentDataDecodersConfiguration,
+    ) {
+        self.encoders = encoders
+        self.decoders = decoders
+        self.defaultType = `default`
+    }
+
+    /// Creates a configuration with default coders and decoders.
+    ///
+    /// - Note: default encoder/decoder is set to JSON
+    public init() {
+        self.init(
+            default: .json,
+            encoders: [
+                .json: JSONEncoder(),
+                .formURLEncoded: FormURLEncoder()
+            ],
+            decoders: [
+                .json: JSONDecoder()
+            ]
+        )
+    }
+}
+
+extension ContentDataCodersConfiguration {
+    /// defines a single encoder to use for encoding `contentType` requests. If an encoder was already defined it will be replaced with the new value
+    public func encoding(_ contentType: HTTPContentType, with encoder: ContentDataEncoder) -> Self {
+        var copy = self
+        copy.encoders[contentType] = encoder
+        return copy
+    }
+
+    /// defines a single decoder for decoding `contentType` responses.  If a decoder was already defined it will be replaced with the new value
+    public func decoding(_ contentType: HTTPContentType, with decoder: ContentDataDecoder) -> Self {
+        var copy = self
+        copy.decoders[contentType] = decoder
+        return copy
+    }
+}

Sources/SimpleHTTP/ContentData/ContentDataCodersConfiguration.swift

@@ -44,7 +44,7 @@ public class Session {
     public func response<Output: Decodable>(for request: Request<Output>) async throws -> Output {
         let result = try await dataPublisher(for: request)
 
-        guard let decoder = config.data.decoder[result.contentType] else {
+        guard let decoder = config.data.decoders[result.contentType] else {
             throw SessionConfigurationError.missingDecoder(result.contentType)
         }
 
@@ -77,10 +77,10 @@ extension Session {
         // FIXME: we also check body inside toURLRequest
         switch modifiedRequest.body {
         case .encodable:
-            encoder = config.data.encoder[requestContentType]
+            encoder = config.data.encoders[requestContentType]
         case .multipart, .none:
             // this one is supposed to never be nil
-            encoder = config.data.encoder[config.data.defaultType]
+            encoder = config.data.encoders[config.data.defaultType]
         }
 
         guard let encoder else {

Sources/SimpleHTTP/Session/Session.swift

@@ -3,7 +3,7 @@ import Foundation
 /// a type defining some parameters for a `Session`
 public struct SessionConfiguration {
     /// data encoders/decoders configuration per content type
-    let data: ContentDataCoderConfiguration
+    let data: ContentDataCodersConfiguration
     /// queue on which to decode data
     let decodingQueue: DispatchQueue
     /// an interceptor to apply custom behavior on the session requests/responses.
@@ -16,7 +16,7 @@ public struct SessionConfiguration {
     /// - Parameter decodeQueue: queue on which to decode data
     /// - Parameter interceptors: interceptor list to apply on the session requests/responses
     public init(
-        data: ContentDataCoderConfiguration = .init(),
+        data: ContentDataCodersConfiguration = .init(),
         decodingQueue: DispatchQueue = .main,
         interceptors: CompositeInterceptor = []) {
             self.data = data
@@ -26,14 +26,14 @@ public struct SessionConfiguration {
 
     /// - Parameter dataError: Error type to use when having error with data
     public init<DataError: Error & Decodable>(
-        data: ContentDataCoderConfiguration,
+        data: ContentDataCodersConfiguration,
         decodingQueue: DispatchQueue = .main,
         interceptors: CompositeInterceptor = [],
         dataError: DataError.Type
     ) {
         self.init(data: data, decodingQueue: decodingQueue, interceptors: interceptors)
-        self.errorConverter = { [decoder=data.decoder] data, contentType in
-            guard let decoder = decoder[contentType] else {
+        self.errorConverter = { [decoders=data.decoders] data, contentType in
+            guard let decoder = decoders[contentType] else {
                 throw SessionConfigurationError.missingDecoder(contentType)
             }
             return try decoder.decode(dataError, from: data)

Sources/SimpleHTTP/Session/SessionConfiguration.swift

@@ -3,10 +3,10 @@ import XCTest
 
 class SessionAsyncTests: XCTestCase {
     let baseURL = URL(string: "https://sessionTests.io")!
-    let data = ContentDataCoderConfiguration(
+    let data = ContentDataCodersConfiguration(
         default: .json,
-        encoder: [.json: JSONEncoder()],
-        decoder: [.json: JSONDecoder()]
+        encoders: [.json: JSONEncoder()],
+        decoders: [.json: JSONDecoder()]
     )
 
     func test_response_responseIsValid_decodedOutputIsReturned() async throws {