swift-code-review

Swift Code Review

Instructions

Step 1: Read All Provided Files

Read every file mentioned or pasted before writing any comments. Do not review code you have not fully read.

If reviewing a PR, ask for:

• The feature or bug being fixed
• The files changed
• Any context about constraints or trade-offs

Step 2: Apply the Review Checklist

Architecture (MVVM)

• Business logic is in ViewModel or Service — not in View/ViewController body
• External dependencies (network, storage, time) are injected via protocol, not hardcoded
• No URLSession.shared, UserDefaults.standard, or Date() called directly from Views
• No global singletons used without injection support
• Thin View layer: no conditional business logic, no data fetching in onAppear without ViewModel delegation

Swift Quality

• No force unwraps (!) in production paths
• Errors propagated via throws or Result — not silently swallowed
• let preferred over var where value does not change
• No magic numbers or hardcoded strings — use named constants or localizable strings
• One primary type per file

Concurrency

• async/await used for all new async code (not completion handlers)
• @MainActor applied to ViewModel and any type that updates UI state
• No DispatchQueue.main.async in ViewModel or Service layers
• No sleep() anywhere
• Sendable conformance considered for types crossing actor boundaries
• Task objects are stored and cancelled if the parent scope is deallocated

Testing

• New business logic has corresponding tests
• New dependencies are injectable (protocol-backed)
• Existing tests still compile and pass
• No test changes that weaken coverage of critical paths

Naming

• Types: UpperCamelCase
• Functions / variables: lowerCamelCase
• Booleans: assertion form (isLoading, hasError, canSubmit, isPremium)
• Avoid abbreviations unless universally understood (url, id, api)
• Test methods: test_when_<Condition>_should_<ExpectedOutcome>()
• Protocol names: noun or adjective, not Protocol suffix (prefer UserRepository over UserRepositoryProtocol where unambiguous, but Protocol suffix is acceptable for clarity)