Add e-mail validator

Sources/SwiftKit/Validation/EmailValidator.swift

@@ -0,0 +1,20 @@
+//
+//  EmailValidator.swift
+//  SwiftKit
+//
+//  Created by Daniel Saidi on 2020-06-09.
+//  Copyright © 2020 Daniel Saidi. All rights reserved.
+//
+
+import Foundation
+
+public class EmailValidator: Validator {
+    
+    public init() {}
+    
+    public func validate(_ string: String) -> Bool {
+        let regExp = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,} ?"
+        let predicate = NSPredicate(format: "SELF MATCHES %@", regExp)
+        return predicate.evaluate(with: string)
+    }
+}

Sources/SwiftKit/Validation/Validator.swift

@@ -0,0 +1,16 @@
+//
+//  Validator.swift
+//  SwiftKit
+//
+//  Created by Daniel Saidi on 2020-06-09.
+//  Copyright © 2020 Daniel Saidi. All rights reserved.
+//
+
+import Foundation
+
+public protocol Validator {
+    
+    associatedtype Validation
+    
+    func validate(_ obj: Validation) -> Bool
+}

Tests/SwiftKitTests/Operations/PerformAsyncTests.swift

@@ -1,19 +0,0 @@
-//
-//  PerformAsyncTests.swift
-//  SwiftKitTests
-//
-//  Created by Daniel Saidi on 2020-06-01.
-//  Copyright © 2020 Daniel Saidi. All rights reserved.
-//
-
-import Quick
-import Nimble
-import SwiftKit
-
-class PerformTests: QuickSpec {
-    
-    override func spec() {
-        
-        
-    }
-}

Tests/SwiftKitTests/Validation/EmailValidatorTests.swift

@@ -0,0 +1,51 @@
+//
+//  PerformAsyncTests.swift
+//  SwiftKitTests
+//
+//  Created by Daniel Saidi on 2020-06-09.
+//  Copyright © 2020 Daniel Saidi. All rights reserved.
+//
+
+import Quick
+import Nimble
+import SwiftKit
+
+class EmailValidatorTests: QuickSpec {
+    
+    override func spec() {
+        
+        describe("email validator") {
+            
+            let validate = EmailValidator().validate
+            
+            context("when validating validating valid addresses") {
+                
+                it("validates valid email addresses") {
+                    expect(validate("foobar@baz.com")).to(beTrue())
+                    expect(validate("foo1.bar2@baz.com")).to(beTrue())
+                    expect(validate("foo.bar@gmail.com")).to(beTrue())
+                }
+                
+                it("validates long top domains") {
+                    expect(validate("foobar@baz.co")).to(beTrue())
+                    expect(validate("foobar@baz.com")).to(beTrue())
+                    expect(validate("foo1.bar2@baz.comm")).to(beTrue())
+                    expect(validate("foo.bar@gmail.commmmmmmmmmmmmmmm")).to(beTrue())
+                }
+            }
+            
+            context("when validating invalid addresses") {
+                
+                it("does not validate invalid email addresses") {
+                    expect(validate("foobar")).to(beFalse())
+                    expect(validate("foo1.bar2@")).to(beFalse())
+                    expect(validate("foo.bar@gmail")).to(beFalse())
+                }
+                
+                it("does not validate too short top domains") {
+                    expect(validate("foobar@baz.c")).to(beFalse())
+                }
+            }
+        }
+    }
+}