| Mechanism | Production | Testing | Debugging |
|---|---|---|---|
| fatalError() in Swift | Terminates the app unconditionally | Terminates the test | Terminates the app unconditionally |
| assertions in Swift | Completely ignored, no effect | Causes test failure if condition fails | Terminates the app if condition fails |
Logger’s .error(_:) | Logs error message without terminating | Logs error message without failing tests | Logs error message without terminating |
Logger’s .info(_:) | Logs informational message | Logs informational message | Logs informational message |
[[IssueReporting|reportIssue()]] by pointfree.co | Shows unobtrusive warnings by default (customizable) | Becomes a test failure | Shows purple runtime warnings in Xcode |
Better Printing
While debugging, it can be easy to get overloaded with irrelevant and poorly formatted logs in the console. Here are some strategies that can help.
Custom Type Summaries
From: (25:07) WWDC24: Run, Break, Inspect: Explore effective debugging in LLDB | Apple - YouTube
Annotate your types with the @DebugDescription macro (after Swift 6).1
@DebugDescription
struct WatchLaterItem {
let video: Video
let name: String
let addedOn: Date
var debugDescription: String {
"\ (name) - \(addedOn)"
}
}