Initial commit

.gitignore

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+.DS_Store
+/.build
+/Packages
+/*.xcodeproj
+xcuserdata/
+DerivedData/
+.swiftpm/

LICENSE

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+MIT License
+
+Copyright (c) 2021 Otavio Cordeiro
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Package.swift

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+// swift-tools-version:5.5
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "MicroClient",
+    platforms: [
+        .macOS(.v11), .iOS(.v13), .tvOS(.v13), .watchOS(.v6)
+    ],
+    products: [
+        .library(
+            name: "MicroClient",
+            targets: ["MicroClient"]
+        )
+    ],
+    dependencies: [],
+    targets: [
+        .target(
+            name: "MicroClient",
+            dependencies: []
+        )
+    ]
+)

README.md

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+# MicroClient
+
+A description of this package.

Sources/MicroClient/Extensions/URLComponents.swift

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+import Foundation
+
+extension URL {
+
+    static func makeURL<RequestModel, ResponseModel>(
+        configuration: NetworkConfiguration,
+        networkRequest: NetworkRequest<RequestModel, ResponseModel>
+    ) throws -> URL {
+        var components = URLComponents()
+
+        components.scheme = configuration.scheme
+        components.host = configuration.hostname
+        components.path = networkRequest.path
+        components.queryItems = networkRequest.queryItems
+
+        return try unwrap(
+            value: components.url,
+            error: NetworkClientError.malformedURL
+        )
+    }
+}

Sources/MicroClient/Extensions/URLRequest.swift

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+import Foundation
+
+extension URLRequest {
+
+    static func makeURLRequest<RequestModel, ResponseModel>(
+        configuration: NetworkConfiguration,
+        networkRequest: NetworkRequest<RequestModel, ResponseModel>
+    ) throws -> URLRequest? {
+        let url = try URL.makeURL(
+            configuration: configuration,
+            networkRequest: networkRequest
+        )
+
+        var request = URLRequest(url: url)
+        request.httpMethod = networkRequest.method.rawValue
+        request.httpBody = try networkRequest.body
+            .map {
+                try networkRequest.encode(
+                    payload: $0,
+                    defaultEncoder: configuration.defaultEncoder
+                )
+            }
+
+        return request
+    }
+}

Sources/MicroClient/Extensions/Unwrap.swift

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+import Combine
+
+func unwrap<T>(
+    value: T?,
+    error: Error
+) throws -> T {
+    guard let value = value else {
+        throw error
+    }
+
+    return value
+}
+
+extension Publisher {
+
+    func unwrap<T>(
+        with error: Failure
+    ) -> Publishers.FlatMap<Result<T, Self.Failure>.Publisher, Self> where Output == T? {
+        flatMap { unwrapped in
+            unwrapped.map { value in
+                Result.success(value).publisher
+            } ?? Result.failure(error).publisher
+        }
+    }
+}

Sources/MicroClient/HTTPMethod.swift

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+import Foundation
+
+public enum HTTPMethod: String {
+    case get = "GET"
+    case post = "POST"
+    case delete = "DELETE"
+    case put = "PUT"
+    case patch = "PATCH"
+}

Sources/MicroClient/NetworkClient.swift

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+import Combine
+import Foundation
+
+public protocol NetworkClientProtocol {
+
+    func run<RequestModel, ResponseModel>(
+        _ networkRequest: NetworkRequest<RequestModel, ResponseModel>
+    ) -> AnyPublisher<NetworkResponse<ResponseModel>, Error>
+}
+
+public final class NetworkClient: NetworkClientProtocol {
+
+    // MARK: - Properties
+
+    private let configuration: NetworkConfiguration
+
+    // MARK: - Life cycle
+
+    public init(
+        configuration: NetworkConfiguration
+    ) {
+        self.configuration = configuration
+    }
+
+    // MARK: - Public
+
+    public func run<RequestModel, ResponseModel>(
+        _ networkRequest: NetworkRequest<RequestModel, ResponseModel>
+    ) -> AnyPublisher<NetworkResponse<ResponseModel>, Error> {
+        urlRequestPublisher(networkRequest: networkRequest)
+            .flatMap { request in
+                self.requestPublisher(
+                    urlRequest: request,
+                    networkRequest: networkRequest
+                )
+            }
+            .receive(on: DispatchQueue.main)
+            .eraseToAnyPublisher()
+    }
+
+    // MARK: - Private
+
+    private func urlRequestPublisher<RequestModel, ResponseModel>(
+        networkRequest: NetworkRequest<RequestModel, ResponseModel>
+    ) -> AnyPublisher<URLRequest, Error> {
+        Result {
+            try URLRequest.makeURLRequest(
+                configuration: configuration,
+                networkRequest: networkRequest
+            )
+        }
+        .publisher
+        .unwrap(with: NetworkClientError.malformedURLRequest)
+        .compactMap { [configuration] request in
+            configuration.interceptor?(request)
+        }
+        .eraseToAnyPublisher()
+    }
+
+    private func requestPublisher<RequestModel, ResponseModel>(
+        urlRequest: URLRequest,
+        networkRequest: NetworkRequest<RequestModel, ResponseModel>
+    ) -> AnyPublisher<NetworkResponse<ResponseModel>, Error> {
+        configuration.session
+            .dataTaskPublisher(for: urlRequest)
+            .tryMap { [configuration] result in
+                NetworkResponse(
+                    value: try networkRequest.decode(
+                        data: result.data,
+                        defaultDecoder: configuration.defaultDecoder
+                    ),
+                    response: result.response
+                )
+            }
+            .eraseToAnyPublisher()
+    }
+}

Sources/MicroClient/NetworkClientError.swift

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+import Foundation
+
+public enum NetworkClientError: Error {
+    case malformedURL
+    case malformedURLRequest
+}

Sources/MicroClient/NetworkConfiguration.swift

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+import Foundation
+
+public final class NetworkConfiguration {
+
+    /// The session used to perform the network requests.
+    public let session: URLSession
+
+    /// The default JSON decoder. It can be overwritten by
+    /// individual requests, if necessary.
+    public let defaultDecoder: JSONDecoder
+
+    /// The default JSON encoder. It can be overwritten by
+    /// individual requests, if necessary.
+    public let defaultEncoder: JSONEncoder
+
+    /// The scheme component of the base URL.
+    public let scheme: String
+
+    /// The host component of the base URL.
+    public let hostname: String
+
+    /// The interceptor called right before performing the
+    /// network request. Can be used to modify the `URLRequest`
+    /// if necessary.
+    public var interceptor: ((URLRequest) -> URLRequest)?
+
+    public init(
+        session: URLSession,
+        defaultDecoder: JSONDecoder,
+        defaultEncoder: JSONEncoder,
+        scheme: String,
+        hostname: String
+    ) {
+        self.session = session
+        self.defaultDecoder = defaultDecoder
+        self.defaultEncoder = defaultEncoder
+        self.scheme = scheme
+        self.hostname = hostname
+    }
+}

Sources/MicroClient/NetworkRequest.swift

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+import Combine
+import Foundation
+
+public struct NetworkRequest<
+    RequestModel,
+    ResponseModel
+> where RequestModel: Encodable, ResponseModel: Decodable {
+
+    // MARK: - Properties
+
+    public let path: String
+    public let method: HTTPMethod
+    public var parameters: [String: String]?
+    public var body: RequestModel?
+    public var decoder: JSONDecoder?
+    public var encoder: JSONEncoder?
+
+    // MARK: - Life cycle
+
+    public init(
+        path: String,
+        method: HTTPMethod,
+        parameters: [String : String]? = nil,
+        body: RequestModel? = nil,
+        decoder: JSONDecoder? = nil,
+        encoder: JSONEncoder? = nil
+    ) {
+        self.path = path
+        self.method = method
+        self.parameters = parameters
+        self.body = body
+        self.decoder = decoder
+        self.encoder = encoder
+    }
+}
+
+// MARK: - Query Items
+
+extension NetworkRequest {
+
+    public var queryItems: [URLQueryItem]? {
+        parameters?.compactMap { parameter in
+            URLQueryItem(
+                name: parameter.key,
+                value: parameter.value
+            )
+        }
+    }
+}
+
+// MARK: - HTTP Body
+
+extension NetworkRequest {
+
+    public func encode(
+        payload: RequestModel,
+        defaultEncoder: JSONEncoder
+    ) throws -> Data {
+        let encoder = encoder ?? defaultEncoder
+        return try encoder.encode(payload)
+    }
+}
+
+// MARK: - Decode
+
+extension NetworkRequest {
+
+    public func decode(
+        data: Data,
+        defaultDecoder: JSONDecoder
+    ) throws -> ResponseModel {
+        let decoder = decoder ?? defaultDecoder
+
+        return try decoder.decode(
+            ResponseModel.self,
+            from: data
+        )
+    }
+}

Sources/MicroClient/NetworkResponse.swift

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+import Foundation
+
+public struct NetworkResponse<T> {
+    public let value: T
+    public let response: URLResponse
+}

Sources/MicroClient/Responses/VoidRequest.swift

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+public struct VoidRequest: Encodable { }

Sources/MicroClient/Responses/VoidResponse.swift

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+public struct VoidResponse: Decodable { }