TM-SGNL-iOS/SignalServiceKit/Util/Error+ErrorLocalizedDescription.swift
TeleMessage developers dde0620daf initial commit
2025-05-03 12:28:28 -07:00

84 lines
2.8 KiB
Swift

//
// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
//
import Foundation
import ObjectiveC
public protocol UserErrorDescriptionProvider {
var localizedDescription: String { get }
}
// MARK: -
extension Error {
public var hasUserErrorDescription: Bool { (self as NSError).hasUserErrorDescriptionImpl }
public var userErrorDescription: String { (self as NSError).userErrorDescriptionImpl }
}
// MARK: -
extension NSError {
@objc
public var hasUserErrorDescription: Bool { hasUserErrorDescriptionImpl }
@objc
public var userErrorDescription: String { userErrorDescriptionImpl }
fileprivate var hasUserErrorDescriptionImpl: Bool {
if self is UserErrorDescriptionProvider {
return true
}
if (self as Error) is UserErrorDescriptionProvider {
return true
}
if let error = self as? LocalizedError,
nil != error.errorDescription {
return true
}
if let error = (self as Error) as? LocalizedError,
nil != error.errorDescription {
return true
}
return false
}
fileprivate var userErrorDescriptionImpl: String {
// Error and NSError have a special relationship.
// They can be "cast" back and forth, but are separate objects.
//
// If Error is cast to NSError, a new NSError will wrap the Error.
// This is called "NSError bridging".
//
// NSError implements Error protocol, but casting NSError to Error
// might unwrap a bridged wrapper.
//
// If you roundtrip-cast Error to NSError and back (or vice versa),
// you should not count on ending up with the same as instance as
// you began with, even though you sometimes will.
//
// When trying to cast an error to IsRetryableProvider,
// we need to try casting both the Error and NSError form.
if let error = self as? UserErrorDescriptionProvider {
return error.localizedDescription
}
if let error = (self as Error) as? UserErrorDescriptionProvider {
return error.localizedDescription
}
if let error = self as? LocalizedError,
let errorDescription = error.errorDescription {
return errorDescription
}
if let error = (self as Error) as? LocalizedError,
let errorDescription = error.errorDescription {
return errorDescription
}
if CurrentAppContext().isRunningTests {
Logger.warn("Presenting error to user without a specific localizedDescription: \(self)")
} else {
owsFailDebug("Presenting error to user without a specific localizedDescription: \(self)")
}
return OWSError.genericErrorDescription()
}
}