coenttb/swift-password-validation

A Swift package for type-safe password validation.

Overview

PasswordValidation provides type-safe password validation in Swift. It includes predefined validation rules and supports custom validation logic through dependency injection.

Features

Predefined validators for common password requirements
Custom validation logic via closure-based composition
Dependencies library integration for testability
Localized error messages in English and Dutch
Sendable conformance for Swift concurrency

Installation

Swift Package Manager

Add the following to your Package.swift file:

dependencies: [
    .package(url: "https://github.com/coenttb/swift-password-validation.git", from: "0.0.1")
]

Then add PasswordValidation to your target dependencies:

.target(
    name: "YourTarget",
    dependencies: [
        .product(name: "PasswordValidation", package: "swift-password-validation")
    ]
)

Quick Start

Basic Usage

import PasswordValidation

// Use the default validator
let validator = PasswordValidation.default

do {
    let isValid = try validator.validate("MySecurePass123!")
    print("Password is valid: \(isValid)")
} catch let error as PasswordValidation.Error {
    print("Validation failed: \(error.description)")
}

With Dependencies

import Dependencies
import PasswordValidation

struct LoginService {
    @Dependency(\.passwordValidation) var passwordValidation

    func validateUserPassword(_ password: String) throws -> Bool {
        return try passwordValidation.validate(password)
    }
}

Usage Examples

Default Validator

The default validator implements standard security requirements:

Length: 8-64 characters
Uppercase: At least one uppercase letter (A-Z)
Lowercase: At least one lowercase letter (a-z)
Digits: At least one digit (0-9)
Special Characters: At least one special character (!&^%$#@()/)

let validator = PasswordValidation.default
try validator.validate("MySecurePass123!") // Returns true

Simple Validator

The simple validator requires only 4+ characters:

let validator = PasswordValidation.simple
try validator.validate("test") // Returns true

Custom Validation

Create your own validation rules:

let customValidator = PasswordValidation { password in
    guard password.count >= 6 else {
        throw PasswordValidation.Error.tooShort(minLength: 6)
    }

    guard !password.lowercased().contains("password") else {
        throw PasswordValidation.Error.missingSpecialCharacter
    }

    return true
}

Error Handling

The library provides specific error types for different validation failures:

do {
    try PasswordValidation.default.validate("weak")
} catch PasswordValidation.Error.tooShort(let minLength) {
    print("Password too short, needs at least \(minLength) characters")
} catch PasswordValidation.Error.missingUppercase {
    print("Password needs an uppercase letter")
} catch PasswordValidation.Error.missingDigit {
    print("Password needs a digit")
} catch {
    print("Other validation error: \(error)")
}

Available Errors

tooShort(minLength: Int) - Password is shorter than required
tooLong(maxLength: Int) - Password exceeds maximum length
missingUppercase - No uppercase letters found
missingLowercase - No lowercase letters found
missingDigit - No digits found
missingSpecialCharacter - No special characters found

License

This project is licensed under the Apache 2.0 License. See LICENSE for details.

Contributing

Contributions are welcome. Please open an issue or submit a pull request.

Package Metadata

Repository: coenttb/swift-password-validation

Homepage: https://coenttb.com

Stars: 2

Forks: 0

Open issues: 2

Default branch: main

Primary language: swift

License: Apache-2.0

Topics: composable-validation, password, password-strength, password-validation, security, swift, type-safe, validation

README: README.md