Raven Dev

Raven Development Skill

Use this skill when working on Raven examples, runtime rendering behavior, DOMBridge event handling, or WASM dev loops.

When To Use

• Build/test a Raven example app
• Reproduce browser-side rendering issues
• Debug DOM event handler wiring
• Validate a framework fix end-to-end in an example

Core Workflow

1. Build phase (prefer app directory)

cd Examples/TodoApp
swift build --swift-sdk swift-6.2.3-RELEASE_wasm

2. Serve phase (from the WASM UI package root, prefer Raven CLI dev server)

cd Examples/TodoApp
raven dev

3. Validate in browser

• Open http://localhost:8000/
• Check console for runtime errors
• Verify UI renders expected state

4. Iterate quickly

• Use python3 raven-dev.py in Examples/TodoApp for automatic rebuild/reload loops.

High-Value Debug Checks

• Browser cache mismatch:
  • compare current WASM checksum against served file
  • use versioned filenames/query params when needed
• DOM event handlers:
  • avoid dynamic JS property access for handler registries
  • prefer JSClosure storage in Swift dictionaries keyed by stable IDs
• Build scope:
  • build from example app directory to avoid unrelated target/tooling failures

Safe DOMBridge Pattern

private var eventClosures: [UUID: JSClosure] = [:]

public func addEventListener(
    element: JSObject,
    event: String,
    handlerID: UUID,
    handler: @escaping @Sendable @MainActor () -> Void
) {
    let jsClosure = JSClosure { _ in
        Task { @MainActor in handler() }
        return .undefined
    }

    eventClosures[handlerID] = jsClosure
    _ = element.addEventListener!(event, jsClosure)
}

Definition of Done

• Repro steps documented
• Relevant tests/builds pass
• Browser console is clean for changed path
• Output behavior verified in example app