Implement examples for validation

TestableDesignExample.xcodeproj/xcshareddata/xcschemes/TestableDesignExampleTests.xcscheme

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   version = "1.3">
+   <BuildAction>
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForRunning = "YES"
+            buildForTesting = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "2475E649AECAE4D1FBC505BA"
+               BuildableName = "TestableDesignExampleTests.xctest"
+               BlueprintName = "TestableDesignExampleTests"
+               ReferencedContainer = "container:TestableDesignExample.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug">
+      <Testables>
+         <TestableReference>
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "2475E649AECAE4D1FBC505BA"
+               BuildableName = "TestableDesignExampleTests.xctest"
+               BlueprintName = "TestableDesignExampleTests"
+               ReferencedContainer = "container:TestableDesignExample.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      useCustomWorkingDirectory = "NO"
+      allowLocationSimulation = "YES">
+      <LocationScenarioReference
+         identifier = "com.apple.dt.IDEFoundation.CurrentLocationScenarioIdentifier"
+         referenceType = "1">
+      </LocationScenarioReference>
+   </LaunchAction>
+</Scheme>

TestableDesignExample/MvcArchitecture/Shared/Validation/Validation.swift

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+import Foundation
+
+
+// NOTE: In general, CharacterSet is not equivalent to Set<Character>, but equivalent to Set<Unicode.Scalar>.
+// SEE: https://github.com/apple/swift/blob/swift-4.0-RELEASE/docs/StringManifesto.md#character-and-characterset
+let asciiLowerAlpha = Set("abcdefghijklmnopqrstuvwxyz")
+let asciiUpperAlpha = Set("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
+let asciiAlpha = asciiLowerAlpha.union(asciiUpperAlpha)
+let asciiDigit = Set("0123456789")
+let asciiAlphaNumeric = asciiAlpha.union(asciiDigit)
+let asciiSymbol = Set(" !\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~")
+let asciiPrintable = asciiAlphaNumeric.union(asciiSymbol)
+
+
+
+func characters(in text: String, without characters: Set<Character>) -> Set<Character> {
+    var characterSet = Set(text)
+    characterSet.subtract(characters)
+    return characterSet
+}
+
+
+
+func string(from characters: Set<Character>) -> String {
+    var result = ""
+
+    characters.sorted().forEach { character in
+        result.append(character)
+    }
+
+    return result
+}

TestableDesignExample/MvcArchitecture/Shared/Validation/ValidationResult.swift

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+enum ValidationResult<V, E> {
+    case success(V)
+    case failure(because: E)
+
+
+    var isSuccess: Bool {
+        switch self {
+        case .success:
+            return true
+        case .failure:
+            return false
+        }
+    }
+
+
+    var value: V? {
+        switch self {
+        case .success(let value):
+            return value
+        case .failure:
+            return nil
+        }
+    }
+
+
+    var reason: E? {
+        switch self {
+        case .success:
+            return nil
+        case .failure(because: let reason):
+            return reason
+        }
+    }
+}
+
+
+
+extension ValidationResult: Equatable where V: Equatable, E: Equatable {
+    static func ==(lhs: ValidationResult<V, E>, rhs: ValidationResult<V, E>) -> Bool {
+        switch (lhs, rhs) {
+        case (.success(let l), .success(let r)):
+            return l == r
+        case (.failure(because: let l), .failure(because: let r)):
+            return l == r
+        default:
+            return false
+        }
+    }
+}

TestableDesignExample/MvcArchitecture/Validation/ExampleValidationComposer.swift

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+import UIKit
+
+
+class ExampleValidationComposer: UIViewController {
+
+}

TestableDesignExample/MvcArchitecture/Validation/Model/ExampleAccount.Draft.swift

@@ -0,0 +1,11 @@
+extension ExampleAccount {
+    struct Draft {
+        let userName: String
+        let password: String
+
+
+        static func createEmpty() -> Draft {
+            return Draft(userName: "", password: "")
+        }
+    }
+}

TestableDesignExample/MvcArchitecture/Validation/Model/ExampleAccount.swift

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+struct ExampleAccount: Equatable {
+    let userName: UserName
+    let password: Password
+
+
+    struct UserName: Equatable {
+        let text: String
+    }
+
+
+    struct Password: Equatable {
+        let text: String
+    }
+}

TestableDesignExample/MvcArchitecture/Validation/Model/ExampleAccount.validate.swift

@@ -0,0 +1,156 @@
+import Foundation
+
+
+
+extension ExampleAccount.Draft {
+    static func validate(draft: ExampleAccount.Draft) -> ValidationResult<ExampleAccount, InvalidReason> {
+        let userNameResult = ExampleAccount.UserName.validate(userName: draft.userName)
+        let passwordResult = ExampleAccount.Password.validate(password: draft.password, userName: draft.userName)
+
+        switch (userNameResult, passwordResult) {
+        case (.success(let userName), .success(let password)):
+            return .success(ExampleAccount(
+                userName: userName,
+                password: password
+            ))
+
+        case (.failure(because: let userNameReason), .success):
+            return .failure(because: InvalidReason(
+                userName: userNameReason,
+                password: []
+            ))
+
+        case (.success, .failure(because: let passwordReason)):
+            return .failure(because: InvalidReason(
+                userName: [],
+                password: passwordReason
+            ))
+
+        case (.failure(because: let userNameReason), .failure(because: let passwordReason)):
+            return .failure(because: InvalidReason(
+                userName: userNameReason,
+                password: passwordReason
+            ))
+        }
+    }
+
+
+    struct InvalidReason: Hashable {
+        let userName: Set<ExampleAccount.UserName.InvalidReason>
+        let password: Set<ExampleAccount.Password.InvalidReason>
+    }
+}
+
+
+extension ExampleAccount.UserName {
+    private static let acceptableCharacters = CharacterSet.letters
+
+
+    static func validate(userName: String) -> ValidationResult<ExampleAccount.UserName, Set<InvalidReason>> {
+        var reasons = Set<InvalidReason>()
+
+        if userName.count < 4 {
+            reasons.insert(.shorterThan4)
+        }
+
+        if userName.count > 30 {
+            reasons.insert(.longerThan30)
+        }
+
+        let invalidChars = characters(in: userName, without: asciiAlphaNumeric)
+        if !invalidChars.isEmpty {
+            reasons.insert(.hasUnavailableChars(found: invalidChars))
+        }
+
+        guard reasons.isEmpty else {
+            return .failure(because: reasons)
+        }
+
+        return .success(ExampleAccount.UserName(text: userName))
+    }
+
+
+    enum InvalidReason: Hashable, Comparable {
+        case shorterThan4
+        case longerThan30
+        case hasUnavailableChars(found: Set<Character>)
+
+
+        static func <(lhs: InvalidReason, rhs: InvalidReason) -> Bool {
+            switch (lhs, rhs) {
+            case (_, .shorterThan4):
+                return false
+            case (.shorterThan4, _):
+                return true
+            case (_, .longerThan30):
+                return false
+            case (.longerThan30, _):
+                return true
+            case (_, .hasUnavailableChars):
+                return false
+            case (.hasUnavailableChars, _):
+                return true
+            }
+        }
+    }
+}
+
+
+extension ExampleAccount.Password {
+    static func validate(password: String, userName: String) -> ValidationResult<ExampleAccount.Password, Set<InvalidReason>> {
+        var reasons = Set<InvalidReason>()
+
+        if password.count < 8 {
+            reasons.insert(.shorterThan8)
+        }
+
+        if password.count > 100 {
+            reasons.insert(.longerThan100)
+        }
+
+        if password == userName {
+            reasons.insert(.sameAsUserName)
+        }
+
+        let invalidChars = characters(in: password, without: asciiPrintable)
+        if !invalidChars.isEmpty {
+            reasons.insert(.hasUnavailableChars(found: invalidChars))
+        }
+
+        guard reasons.isEmpty else {
+            return .failure(because: reasons)
+        }
+
+        return .success(ExampleAccount.Password(text: password))
+    }
+
+
+    enum InvalidReason: Hashable, Comparable {
+        case shorterThan8
+        case longerThan100
+        case hasUnavailableChars(found: Set<Character>)
+        case sameAsUserName
+
+
+        static func <(lhs: InvalidReason, rhs: InvalidReason) -> Bool {
+            switch (lhs, rhs) {
+            case (_, .shorterThan8):
+                return false
+            case (.shorterThan8, _):
+                return true
+            case (_, .longerThan100):
+                return false
+            case (.longerThan100, _):
+                return true
+            case (_, .hasUnavailableChars):
+                return false
+            case (.hasUnavailableChars, _):
+                return true
+            case (_, .sameAsUserName):
+                return false
+            case (.sameAsUserName, _):
+                return true
+            }
+        }
+    }
+}

TestableDesignExample/MvcArchitecture/Validation/Model/ExampleAccount.validateTests.swift

@@ -0,0 +1,192 @@
+import XCTest
+import MirrorDiffKit
+@testable import TestableDesignExample
+
+
+
+class ExampleAccountTests: XCTestCase {
+    func testValidate() {
+    	typealias TestCase = (
+            input: ExampleAccount.Draft,
+            expected: ValidationResult<ExampleAccount, ExampleAccount.Draft.InvalidReason>
+    	)
+
+    	let testCases: [UInt: TestCase] = [
+            #line: (
+                input: .init(
+                    userName: "userName",
+                    password: "password"
+                ),
+                expected: .success(ExampleAccount(
+                    userName: .init(text: "userName"),
+                    password: .init(text: "password")
+                ))
+            ),
+            #line: (
+                input: .init(
+                    userName: "",
+                    password: "password"
+                ),
+                expected: .failure(
+                    because: .init(userName: [.shorterThan4], password: [])
+                )
+            ),
+            #line: (
+                input: .init(
+                    userName: "userName",
+                    password: ""
+                ),
+                expected: .failure(
+                    because: .init(userName: [], password: [.shorterThan8])
+                )
+            ),
+            #line: (
+                input: .init(
+                    userName: "u",
+                    password: "p"
+                ),
+                expected: .failure(
+                    because: .init(
+                        userName: [.shorterThan4],
+                        password: [.shorterThan8]
+                    )
+                )
+            ),
+            #line: (
+                input: .init(
+                    userName: "userName",
+                    password: "userName"
+                ),
+                expected: .failure(
+                    because: .init(
+                        userName: [],
+                        password: [.sameAsUserName]
+                    )
+                )
+            ),
+    	]
+
+    	testCases.forEach { tuple in
+    	    let (line, (input: draft, expected: expected)) = tuple
+
+            let actual = ExampleAccount.Draft.validate(draft: draft)
+
+            XCTAssertEqual(expected, actual, diff(between: actual, and: expected), line: line)
+    	}
+    }
+}
+
+
+
+class ExampleAccountUserNameTests: XCTestCase {
+    func testValidate() {
+    	typealias TestCase = (
+			input: String,
+			expected: ValidationResult<ExampleAccount.UserName, Set<ExampleAccount.UserName.InvalidReason>>
+    	)
+
+    	let testCases: [UInt: TestCase] = [
+    	    #line: (
+                input: "",
+                expected: .failure(because: [.shorterThan4])
+            ),
+            #line: (
+                input: String(repeating: "x", count: 3),
+                expected: .failure(because: [.shorterThan4])
+            ),
+            #line: (
+                input: String(repeating: "x", count: 4),
+                expected: .success(.init(text: String(repeating: "x", count: 4)))
+            ),
+            #line: (
+                input: String(repeating: "x", count: 30),
+                expected: .success(.init(text: String(repeating: "x", count: 30)))
+            ),
+            #line: (
+                input: String(repeating: "x", count: 31),
+                expected: .failure(because: [.longerThan30])
+            ),
+            #line: (
+                input: string(from: asciiDigit),
+                expected: .success(.init(text: string(from: asciiDigit)))
+            ),
+            #line: (
+                input: string(from: asciiLowerAlpha),
+                expected: .success(.init(text: string(from: asciiLowerAlpha)))
+            ),
+            #line: (
+                input: string(from: asciiUpperAlpha),
+                expected: .success(.init(text: string(from: asciiUpperAlpha)))
+            ),
+            #line: (
+                input: "abcd1234ABCD",
+                expected: .success(.init(text: "abcd1234ABCD"))
+            ),
+            #line: (
+                input: string(from: asciiSymbol),
+                expected: .failure(because: [
+                    .longerThan30,
+                    .hasUnavailableChars(found: asciiSymbol),
+                ])
+            ),
+    	]
+
+    	testCases.forEach { tuple in
+    	    let (line, (input: input, expected: expected)) = tuple
+
+            let actual = ExampleAccount.UserName.validate(userName: input)
+
+            XCTAssertEqual(expected, actual, diff(between: actual, and: expected), line: line)
+    	}
+    }
+}
+
+
+
+class ExampleAccountPasswordTests: XCTestCase {
+    func testValidate() {
+    	typealias TestCase = (
+            input: (password: String, userName: String),
+            expected: ValidationResult<ExampleAccount.Password, Set<ExampleAccount.Password.InvalidReason>>
+        )
+
+    	let testCases: [UInt: TestCase] = [
+    	    #line: (
+                input: (password: "", userName: "userName"),
+                expected: .failure(because: [.shorterThan8])
+            ),
+            #line: (
+                input: (password: String(repeating: "x", count: 7), userName: "userName"),
+                expected: .failure(because: [.shorterThan8])
+            ),
+            #line: (
+                input: (password: String(repeating: "x", count: 8), userName: "userName"),
+                expected: .success(.init(text: String(repeating: "x", count: 8)))
+            ),
+            #line: (
+                input: (password: String(repeating: "x", count: 100), userName: "userName"),
+                expected: .success(.init(text: String(repeating: "x", count: 100)))
+            ),
+            #line: (
+                input: (password: String(repeating: "x", count: 101), userName: "userName"),
+                expected: .failure(because: [.longerThan100])
+            ),
+            #line: (
+                input: (password: string(from: asciiPrintable), userName: "userName"),
+                expected: .success(.init(text: string(from: asciiPrintable)))
+            ),
+            #line: (
+                input: (password: "userName", userName: "userName"),
+                expected: .failure(because: [.sameAsUserName])
+            ),
+    	]
+
+    	testCases.forEach { tuple in
+    	    let (line, (input: (password: password, userName: userName), expected: expected)) = tuple
+
+            let actual = ExampleAccount.Password.validate(password: password, userName: userName)
+
+            XCTAssertEqual(expected, actual, diff(between: actual, and: expected), line: line)
+    	}
+    }
+}

TestableDesignExample/MvcArchitecture/Validation/Model/ExampleAccountFactory.swift

@@ -0,0 +1,33 @@
+@testable import TestableDesignExample
+
+
+
+enum ExampleAccountFactory {
+    static func create(
+        userName: ExampleAccount.UserName = UserNameFactory.create(),
+        password: ExampleAccount.Password = PasswordFactory.create()
+    ) -> ExampleAccount {
+        return ExampleAccount(userName: userName, password: password)
+    }
+
+
+    enum UserNameFactory {
+        static func create(text: String = "userName") -> ExampleAccount.UserName {
+            return .init(text: text)
+        }
+    }
+
+
+    enum PasswordFactory {
+        static func create(text: String = "userName") -> ExampleAccount.Password {
+            return .init(text: text)
+        }
+    }
+
+
+    enum DraftFactory {
+        static func create(userName: String = "", password: String = "") -> ExampleAccount.Draft {
+            return ExampleAccount.Draft(userName: userName, password: password)
+        }
+    }
+}

TestableDesignExample/MvcArchitecture/Validation/Model/ExampleValidationModel.swift

@@ -0,0 +1,49 @@
+import RxCocoa
+
+
+
+protocol ExampleValidationModelProtocol {
+    var currentState: ExampleValidationModelState { get }
+    var didChange: RxCocoa.Driver<ExampleValidationModelState> { get }
+
+    func update(by draft: ExampleAccount.Draft)
+}
+
+
+
+enum ExampleValidationModelState: Equatable {
+    case notValidatedYet
+    case validated(ValidationResult<ExampleAccount, ExampleAccount.Draft.InvalidReason>)
+}
+
+
+
+class ExampleValidationModel: ExampleValidationModelProtocol {
+    typealias Strategy = (ExampleAccount.Draft) -> ValidationResult<ExampleAccount, ExampleAccount.Draft.InvalidReason>
+
+
+    private let stateMachine: StateMachine<ExampleValidationModelState>
+    private let validate: Strategy
+
+
+    var currentState: ExampleValidationModelState {
+        return self.stateMachine.currentState
+    }
+
+
+    var didChange: Driver<ExampleValidationModelState> {
+        return self.stateMachine.didChange
+    }
+
+
+    init(startingWith initialState: ExampleValidationModelState, validatingBy strategy: @escaping Strategy) {
+        self.stateMachine = StateMachine(startingWith: initialState)
+        self.validate = strategy
+    }
+
+
+    func update(by draft: ExampleAccount.Draft) {
+        let result = self.validate(draft)
+        self.stateMachine.transit(to: .validated(result))
+    }
+}

TestableDesignExample/MvcArchitecture/Validation/Model/ExampleValidationModelTests.swift

@@ -0,0 +1,80 @@
+import XCTest
+import MirrorDiffKit
+@testable import TestableDesignExample
+
+
+
+class ExampleValidationModelTests: XCTestCase {
+    func testNotValidatedYet() {
+        let model = ExampleValidationModel(
+            startingWith: .notValidatedYet,
+            validatingBy: self.createDummyStrategy()
+        )
+
+        let actual = model.currentState
+
+        let expected: ExampleValidationModelState = .notValidatedYet
+        XCTAssertEqual(actual, expected, diff(between: expected, and: actual))
+    }
+
+
+    func testSuccess() {
+        let account = ExampleAccountFactory.create()
+        let model = ExampleValidationModel(
+            startingWith: .notValidatedYet,
+            validatingBy: self.createSuccessfulStrategy(account: account)
+        )
+
+        let anyDraft = ExampleAccountFactory.DraftFactory.create()
+        model.update(by: anyDraft)
+
+        let actual = model.currentState
+        let expected: ExampleValidationModelState = .validated(.success(account))
+        XCTAssertEqual(actual, expected, diff(between: expected, and: actual))
+    }
+
+
+    func testFailure() {
+        let reason = self.createAnyDraftInvalidReasonSet()
+        let model = ExampleValidationModel(
+            startingWith: .notValidatedYet,
+            validatingBy: self.createFailedStrategy(reason: reason)
+        )
+
+        let anyDraft = ExampleAccountFactory.DraftFactory.create()
+        model.update(by: anyDraft)
+
+        let actual = model.currentState
+        let expected: ExampleValidationModelState = .validated(.failure(because: reason))
+        XCTAssertEqual(actual, expected, diff(between: expected, and: actual))
+    }
+
+
+    private func createDummyStrategy() -> ExampleValidationModel.Strategy {
+        return { _ in
+            fatalError("It should not affect to test results")
+        }
+    }
+
+
+    private func createSuccessfulStrategy(account: ExampleAccount) -> ExampleValidationModel.Strategy {
+        return { _ in
+            return .success(account)
+        }
+    }
+
+
+    private func createFailedStrategy(reason: ExampleAccount.Draft.InvalidReason) -> ExampleValidationModel.Strategy {
+        return { _ in
+            return .failure(because: reason)
+        }
+    }
+
+
+    private func createAnyDraftInvalidReasonSet() -> ExampleAccount.Draft.InvalidReason {
+        return ExampleAccount.Draft.InvalidReason(
+            userName: [.shorterThan4],
+            password: [.shorterThan8]
+        )
+    }
+}

TestableDesignExample/MvcArchitecture/Validation/View/UIKitSubClass/ExampleValidationScreenRootView.swift

@@ -0,0 +1,35 @@
+import UIKit
+
+
+
+class ExampleValidationScreenRootView: UIView {
+    @IBOutlet weak var nameTextField: UITextField!
+    @IBOutlet weak var passwordTextField: UITextField!
+    @IBOutlet weak var userNameHintLabel: UILabel!
+    @IBOutlet weak var passwordHintLabel: UILabel!
+
+
+    override init(frame: CGRect) {
+        super.init(frame: frame)
+        self.loadFromXib()
+    }
+
+
+    required init?(coder aDecoder: NSCoder) {
+        super.init(coder: aDecoder)
+        self.loadFromXib()
+    }
+
+
+    private func loadFromXib() {
+        guard let view = R.nib.exampleValidationScreenRootView.firstView(owner: self) else {
+            return
+        }
+
+        view.translatesAutoresizingMaskIntoConstraints = false
+        self.addSubview(view)
+
+        FilledLayout.fill(subview: view, into: self)
+        self.layoutIfNeeded()
+    }
+}

TestableDesignExample/MvcArchitecture/Validation/View/UIKitSubClass/ExampleValidationScreenRootView.xib

@@ -0,0 +1,132 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="14313.18" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES">
+    <device id="retina4_7" orientation="portrait">
+        <adaptation id="fullscreen"/>
+    </device>
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="14283.14"/>
+        <capability name="Safe area layout guides" minToolsVersion="9.0"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <objects>
+        <placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner" customClass="ExampleValidationScreenRootView" customModule="TestableDesignExample" customModuleProvider="target">
+            <connections>
+                <outlet property="nameTextField" destination="Y5r-gr-OPr" id="3lC-Ul-rvc"/>
+                <outlet property="passwordHintLabel" destination="fYa-66-MCR" id="q8H-vT-pZb"/>
+                <outlet property="passwordTextField" destination="tUz-p2-VGw" id="48l-6u-hde"/>
+                <outlet property="userNameHintLabel" destination="OqQ-b6-Sa1" id="3jA-2U-Ayp"/>
+            </connections>
+        </placeholder>
+        <placeholder placeholderIdentifier="IBFirstResponder" id="-2" customClass="UIResponder"/>
+        <view contentMode="scaleToFill" id="iN0-l3-epB">
+            <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+            <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+            <subviews>
+                <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="L54-9W-H0s">
+                    <rect key="frame" x="20" y="207.5" width="335" height="272.5"/>
+                    <subviews>
+                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Example Validation" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="x45-BB-Mps">
+                            <rect key="frame" x="0.0" y="0.0" width="335" height="27.5"/>
+                            <fontDescription key="fontDescription" type="boldSystem" pointSize="23"/>
+                            <nil key="textColor"/>
+                            <nil key="highlightedColor"/>
+                        </label>
+                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Name" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="vTD-91-wb0">
+                            <rect key="frame" x="0.0" y="39.5" width="335" height="21"/>
+                            <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                            <nil key="textColor"/>
+                            <nil key="highlightedColor"/>
+                        </label>
+                        <textField opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="left" contentVerticalAlignment="center" textAlignment="natural" minimumFontSize="17" translatesAutoresizingMaskIntoConstraints="NO" id="Y5r-gr-OPr" userLabel="Name field">
+                            <rect key="frame" x="0.0" y="66.5" width="335" height="34"/>
+                            <color key="backgroundColor" cocoaTouchSystemColor="groupTableViewBackgroundColor"/>
+                            <constraints>
+                                <constraint firstAttribute="height" constant="34" id="1W5-ZR-2X9"/>
+                            </constraints>
+                            <nil key="textColor"/>
+                            <fontDescription key="fontDescription" type="system" pointSize="14"/>
+                            <textInputTraits key="textInputTraits"/>
+                        </textField>
+                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="OqQ-b6-Sa1" userLabel="Name hint">
+                            <rect key="frame" x="0.0" y="108.5" width="335" height="22"/>
+                            <constraints>
+                                <constraint firstAttribute="height" constant="22" id="dVl-D2-YJN"/>
+                            </constraints>
+                            <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                            <color key="textColor" red="1" green="0.14913141730000001" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                            <nil key="highlightedColor"/>
+                        </label>
+                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Password" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="AGU-wy-eGC">
+                            <rect key="frame" x="0.0" y="146.5" width="335" height="21"/>
+                            <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                            <nil key="textColor"/>
+                            <nil key="highlightedColor"/>
+                        </label>
+                        <textField opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="left" contentVerticalAlignment="center" textAlignment="natural" minimumFontSize="17" translatesAutoresizingMaskIntoConstraints="NO" id="tUz-p2-VGw" userLabel="Password field">
+                            <rect key="frame" x="0.0" y="175.5" width="335" height="34"/>
+                            <color key="backgroundColor" cocoaTouchSystemColor="groupTableViewBackgroundColor"/>
+                            <constraints>
+                                <constraint firstAttribute="height" constant="34" id="DGy-YA-cvZ"/>
+                            </constraints>
+                            <nil key="textColor"/>
+                            <fontDescription key="fontDescription" type="system" pointSize="14"/>
+                            <textInputTraits key="textInputTraits"/>
+                        </textField>
+                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="NOTE: This information do not send to anywhere!" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="YqM-5a-GRB" userLabel="Note">
+                            <rect key="frame" x="0.0" y="255.5" width="335" height="17"/>
+                            <fontDescription key="fontDescription" type="system" pointSize="14"/>
+                            <color key="textColor" white="0.66666666666666663" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                            <nil key="highlightedColor"/>
+                        </label>
+                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="fYa-66-MCR" userLabel="Password hint">
+                            <rect key="frame" x="0.0" y="217.5" width="335" height="22"/>
+                            <constraints>
+                                <constraint firstAttribute="height" constant="22" id="Y6A-oV-rFj"/>
+                            </constraints>
+                            <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                            <color key="textColor" red="1" green="0.14913141730000001" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                            <nil key="highlightedColor"/>
+                        </label>
+                    </subviews>
+                    <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                    <constraints>
+                        <constraint firstAttribute="trailing" secondItem="tUz-p2-VGw" secondAttribute="trailing" id="8gq-vp-0c6"/>
+                        <constraint firstAttribute="trailing" secondItem="vTD-91-wb0" secondAttribute="trailing" id="9ZB-iX-KQq"/>
+                        <constraint firstAttribute="trailing" secondItem="x45-BB-Mps" secondAttribute="trailing" id="An9-an-O6A"/>
+                        <constraint firstItem="vTD-91-wb0" firstAttribute="leading" secondItem="L54-9W-H0s" secondAttribute="leading" id="CUt-fT-MLp"/>
+                        <constraint firstItem="tUz-p2-VGw" firstAttribute="top" secondItem="AGU-wy-eGC" secondAttribute="bottom" constant="8" id="IF2-VP-k7v"/>
+                        <constraint firstItem="x45-BB-Mps" firstAttribute="top" secondItem="L54-9W-H0s" secondAttribute="top" id="Iik-qN-oJ0"/>
+                        <constraint firstItem="vTD-91-wb0" firstAttribute="top" secondItem="x45-BB-Mps" secondAttribute="bottom" constant="12" id="KdI-Y1-Nrr"/>
+                        <constraint firstAttribute="bottom" secondItem="YqM-5a-GRB" secondAttribute="bottom" id="Ko9-ZP-eod"/>
+                        <constraint firstAttribute="trailing" secondItem="Y5r-gr-OPr" secondAttribute="trailing" id="MgQ-Qn-k1X"/>
+                        <constraint firstItem="Y5r-gr-OPr" firstAttribute="leading" secondItem="L54-9W-H0s" secondAttribute="leading" id="RQ9-7k-TdG"/>
+                        <constraint firstItem="AGU-wy-eGC" firstAttribute="top" secondItem="OqQ-b6-Sa1" secondAttribute="bottom" constant="16" id="SZd-wc-IWc"/>
+                        <constraint firstAttribute="trailing" secondItem="YqM-5a-GRB" secondAttribute="trailing" id="TLj-mp-piv"/>
+                        <constraint firstItem="tUz-p2-VGw" firstAttribute="leading" secondItem="L54-9W-H0s" secondAttribute="leading" id="fKT-R9-1R6"/>
+                        <constraint firstItem="OqQ-b6-Sa1" firstAttribute="leading" secondItem="L54-9W-H0s" secondAttribute="leading" id="fZ4-6G-mMH"/>
+                        <constraint firstItem="YqM-5a-GRB" firstAttribute="leading" secondItem="L54-9W-H0s" secondAttribute="leading" id="fni-i2-mIN"/>
+                        <constraint firstItem="fYa-66-MCR" firstAttribute="leading" secondItem="L54-9W-H0s" secondAttribute="leading" id="hWN-ko-yAh"/>
+                        <constraint firstAttribute="trailing" secondItem="AGU-wy-eGC" secondAttribute="trailing" id="jP1-OY-dDQ"/>
+                        <constraint firstItem="OqQ-b6-Sa1" firstAttribute="top" secondItem="Y5r-gr-OPr" secondAttribute="bottom" constant="8" id="lL1-98-ez0"/>
+                        <constraint firstItem="fYa-66-MCR" firstAttribute="top" secondItem="tUz-p2-VGw" secondAttribute="bottom" constant="8" id="mCi-gp-8Uj"/>
+                        <constraint firstAttribute="trailing" secondItem="fYa-66-MCR" secondAttribute="trailing" id="mdH-8J-Wbr"/>
+                        <constraint firstItem="x45-BB-Mps" firstAttribute="leading" secondItem="L54-9W-H0s" secondAttribute="leading" id="pgm-Ls-UXf"/>
+                        <constraint firstItem="YqM-5a-GRB" firstAttribute="top" secondItem="fYa-66-MCR" secondAttribute="bottom" constant="16" id="psn-WT-Dj0"/>
+                        <constraint firstItem="Y5r-gr-OPr" firstAttribute="top" secondItem="vTD-91-wb0" secondAttribute="bottom" constant="6" id="qga-wa-7OZ"/>
+                        <constraint firstAttribute="trailing" secondItem="OqQ-b6-Sa1" secondAttribute="trailing" id="vhF-uW-syT"/>
+                        <constraint firstItem="AGU-wy-eGC" firstAttribute="leading" secondItem="L54-9W-H0s" secondAttribute="leading" id="wf6-HC-REz"/>
+                    </constraints>
+                </view>
+            </subviews>
+            <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+            <constraints>
+                <constraint firstItem="L54-9W-H0s" firstAttribute="centerY" secondItem="vUN-kp-3ea" secondAttribute="centerY" id="WKk-FB-vfK"/>
+                <constraint firstItem="vUN-kp-3ea" firstAttribute="trailing" secondItem="L54-9W-H0s" secondAttribute="trailing" constant="20" id="brt-tQ-7cK"/>
+                <constraint firstItem="L54-9W-H0s" firstAttribute="leading" secondItem="vUN-kp-3ea" secondAttribute="leading" constant="20" id="dA9-Of-Te8"/>
+            </constraints>
+            <viewLayoutGuide key="safeArea" id="vUN-kp-3ea"/>
+            <point key="canvasLocation" x="53.600000000000001" y="48.125937031484263"/>
+        </view>
+    </objects>
+</document>

TestableDesignExample/MvcArchitecture/Validation/View/ViewBinding/ExampleValidationViewBinding.swift

@@ -0,0 +1,83 @@
+import UIKit
+import RxSwift
+import RxCocoa
+
+
+
+protocol ExampleValidationViewBindingProtocol {}
+
+
+
+class ExampleValidationViewBinding: ExampleValidationViewBindingProtocol {
+    private let disposeBag = RxSwift.DisposeBag()
+    private let model: ExampleValidationModelProtocol
+    private let view: ExampleValidationScreenRootView
+
+
+    init(
+        observing model: ExampleValidationModelProtocol,
+        handling view: ExampleValidationScreenRootView
+    ) {
+        self.model = model
+        self.view = view
+
+        self.model.didChange
+            .drive(onNext: { [weak self] state in
+                guard let this = self else { return }
+
+                switch state {
+                case .notValidatedYet:
+                    this.view.userNameHintLabel.text = ""
+                    this.view.userNameHintLabel.backgroundColor = ColorPalette.Form.Background.normal
+                    this.view.passwordHintLabel.text = ""
+                    this.view.passwordHintLabel.backgroundColor = ColorPalette.Form.Background.normal
+
+                case .validated(.success):
+                    this.view.userNameHintLabel.text = ""
+                    this.view.userNameHintLabel.backgroundColor = ColorPalette.Form.Background.ok
+                    this.view.passwordHintLabel.text = ""
+                    this.view.passwordHintLabel.backgroundColor = ColorPalette.Form.Background.ok
+
+                case .validated(.failure(because: let reason)):
+                    if let userNameReason = reason.userName.sorted().first {
+                        let userNameHint: String
+                        switch userNameReason {
+                        case .shorterThan4:
+                            userNameHint = "Must be longer than 8"
+                        case .longerThan30:
+                            userNameHint = "Must be shorter than 100"
+                        case .hasUnavailableChars(found: let characters):
+                            userNameHint = "Unavailable characters: \(string(from: characters))"
+                        }
+                        this.view.userNameHintLabel.text = userNameHint
+                        this.view.userNameHintLabel.backgroundColor = ColorPalette.Form.Background.ng
+                    }
+                    else {
+                        this.view.userNameHintLabel.text = ""
+                        this.view.userNameHintLabel.backgroundColor = ColorPalette.Form.Background.ok
+                    }
+
+                    if let passwordReason = reason.password.sorted().first {
+                        let passwordHint: String
+                        switch passwordReason {
+                        case .shorterThan8:
+                            passwordHint = "Must be longer than 8"
+                        case .longerThan100:
+                            passwordHint = "Must be shorter than 100"
+                        case .hasUnavailableChars(found: let characters):
+                            passwordHint = "Unavailable characters: \(string(from: characters))"
+                        case .sameAsUserName:
+                            passwordHint = "Must be difference the user name"
+                        }
+                        this.view.passwordHintLabel.text = passwordHint
+                        this.view.passwordHintLabel.backgroundColor = ColorPalette.Form.Background.ng
+                    }
+                    else {
+                        this.view.passwordHintLabel.text = ""
+                        this.view.passwordHintLabel.backgroundColor = ColorPalette.Form.Background.ok
+                    }
+                }
+            })
+            .disposed(by: self.disposeBag)
+    }
+}

TestableDesignExample/Resources/Color.swift

@@ -0,0 +1,32 @@
+import UIKit
+
+
+
+enum ColorPalette {
+    enum Form {
+        enum Background {
+            static let normal = UIColor(
+                hue: 0.666,
+                saturation: 0.020,
+                brightness: 0.960,
+                alpha: 0
+            )
+
+
+            static let ng = UIColor(
+                hue: 0.005,
+                saturation: 0.280,
+                brightness: 1,
+                alpha: 1
+            )
+
+
+            static let ok = UIColor(
+                hue: 0.311,
+                saturation: 0.280,
+                brightness: 1,
+                alpha: 1
+            )
+        }
+    }
+}