Files
discogs-service/Sources/DiscogsService/Internal/Validation Rules/URLValidationRule.swift
T

84 lines
2.7 KiB
Swift

// ===----------------------------------------------------------------------===
//
// This source file is part of the DiscogsService open source project
//
// Copyright (c) 2026 Röck+Cöde VoF. and the DiscogsService project authors
// Licensed under Apache license v2.0
//
// See LICENSE for license information
// See CONTRIBUTORS for the list of DiscogsService project authors
//
// SPDX-License-Identifier: Apache-2.0
//
// ===----------------------------------------------------------------------===
/// A validation rule type that checks whether an input is a URL or not.
///
/// This validation rule doesn't necessarily follow the [RFC 3986](https://www.rfc-editor.org/rfc/rfc3986) standard.
/// Thus it doesn't implement a complex regular expression pattern such as [this one](https://rgxdb.com/r/5JXUI5A2).
/// Instead this validation implements a regular expression sufficient enough to satisfy the requirements for a [user agent definition](https://www.discogs.com/developers/#page:home,header:home-general-information).
struct URLValidationRule: InputValidationRule {
// MARK: Functions
#if swift(>=6.0)
func validate(_ input: String?) throws(InputValidationError) -> Bool {
try validate(input: input)
}
#else
func validate(_ input: String?) throws -> Bool {
try validate(input: input)
}
#endif
}
// MARK: - Definitions
extension InputValidationRule where Self == URLValidationRule {
// MARK: Constants
/// A validation rule that checks whether an input is a URL or not.
static var url: Self { .init() }
}
// MARK: - Helpers
private extension URLValidationRule {
// MARK: Functions
/// Validates a given input.
///
/// > note: This helper function would not be necessary when support for *Swift 5.10* is discontinued.
///
/// - Parameter input: An input to be validated.
/// - Returns: A flag that indicates whether a given input has been validated or not.
/// - Throws: An error of type ``InputValidatorError`` in case the validation failed.
func validate(input: String?) throws -> Bool {
guard let input else {
return false
}
guard input.fullyMatch(
pattern: .init(format: .Pattern.url)
) else {
throw InputValidationError.inputNotURL
}
return true
}
}
// MARK: - Constants
private extension String.Pattern {
/// A regular expression pattern that represents URL inputs.
///
/// This regular expression is based on [this regular expression](https://regex101.com/r/3fYy3x/1) found while researching the topic.
static let url = "https?:\\/\\/(www\\.)?[-a-zA-Z0-9@:%._\\+~#=]{2,256}\\.[a-z]{2,4}\\b([-a-zA-Z0-9@:%_\\+.~#?&//=]*)"
}