AWS Router: ReferenceError when viewerRequest injection uses await

[charliecode]

Using await in edge.viewerRequest.injection breaks access to routerNS inside getRoutes(), throwing ReferenceError: cannot access variable before initialization.

Reproduction

const router = new sst.aws.Router('Router', {
  edge: {
    viewerRequest: {
      injection: `
        await cf.kvs().get('some-key');
      `
    }
  }
});

Make a request that triggers the injected code → Error when getRoutes() accesses routerNS.

Code Structure

The Router component creates CloudFront Function code with this structure:

async function handler(event) {
  ${userInjection}
  ${blockCloudfrontUrlInjection}
  ${CF_ROUTER_INJECTION}

  const routerNS = "${kvNamespace}";

  async function getRoutes() {
    const v = await cf.kvs().get(routerNS + ":routes"); // Error here
  }
  
  const routes = await getRoutes();
}

What Works

• Moving routerNS declaration inside getRoutes() function → Fixes the error
• Synchronous injected code (no await) → Works, but no good if you want to exit early

What Doesn't Work

• Async injected code with await → Breaks routerNS access inside getRoutes()

Error

ReferenceError: cannot access variable before initialization

Occurs when getRoutes() tries to access routerNS. CloudWatch logs show routerNS is declared but inaccessible from inside getRoutes().

Environment

• SST Version: 3.17.23
• Node Version: >=22.0.0
• CloudFront Functions runtime: cloudfront-js-2.0

[charliecode]

I've submitted a PR that should fix this: #6332

[vimtor]

fixed in v3.18.0