code-design.md

Flowcrypt-ios Code Design

Error Handling

We have extension with errorMessage property for Error.

It checks if Error has some custom message using CustomStringConvertible protocol, otherwise it uses localizedDescription property.

public extension Error {
    var errorMessage: String {
        switch self {
        case let self as CustomStringConvertible:
            return String(describing: self)
        default:
            return localizedDescription
        }
    }
}

Here is example of error with custom messages - https://github.com/FlowCrypt/flowcrypt-ios/blob/master/FlowCrypt/Functionality/Services/Compose%20Message%20Service/ComposeMessageError.swift

Task Handling

• There should generally be only one "grand" try/catch inside each Task.
• There should be generally a single Task right in each handler. And then all errors downstream should mostly be re-thrown.