Overview

TIL 😅
BridgeJS was generating invalid TypeScript declarations for functions inside namespace blocks. The generated code looked like:

declare global {
    namespace Utils {
        namespace String {
            uppercase(text: string): string;  // ❌ Invalid TypeScript
        }
    }
}

This is a syntax error in TypeScript. Unlike class methods, functions inside TypeScript namespace declarations require the explicit function keyword.

Why this wasn't caught:
JavaScriptKit's tsconfig.json uses "skipLibCheck": true, which skips type-checking of declaration files (.d.ts). The JavaScript E2E tests also passed because JavaScript doesn't have namespace - it only sees the compiled runtime objects.

Project which runs strict TypeScript type-checking (tsc --noEmit) without skipLibCheck fails due to that

Fix

Added the function keyword prefix when generating function declarations inside namespaces:

declare global {
    namespace Utils {
        namespace String {
            function uppercase(text: string): string;  // ✅ Valid TypeScript
        }
    }
}