A simple technique to trim whitespace from URLs before decoding them with Swift Codable.

KeyedDecodingContainerURL.swift

public extension KeyedDecodingContainer {
	func decode(_ type: URL.Type, forKey key: KeyedDecodingContainer.Key) throws -> URL {
		let stringValue = try decode(String.self, forKey: key)
		guard let url = URL(string: stringValue.trimmingWhiteSpace) else {
			throw DecodingError.dataCorruptedError(forKey: key, in: self, debugDescription: "Invalid URL string.")
		}
		return url
	}

	func decodeIfPresent(_ type: URL.Type, forKey key: KeyedDecodingContainer.Key) throws -> URL? {
		guard let stringValue = try decodeIfPresent(String.self, forKey: key) else {
			return nil
		}
		guard let url = URL(string: stringValue.trimmingWhiteSpace) else {
			throw DecodingError.dataCorruptedError(forKey: key, in: self, debugDescription: "Invalid URL string.")
		}
		return url
	}
}

Nice extension!

New update: stringValue.trimmingWhiteSpace => stringValue.trimmingCharacters(in: .whitespacesAndNewlines) :)