This is a minimal example demoing Nextjs 12.2 Edge Runtime failing to be detected, instead running in the default Nodejs runtime instead.
The example Edge API route, does only one thing: log out the req, event objects received as arguments for the handler function, as well as the req.url which should be a complete URL string with protocol and origin.
According to the documentation for this feature, Edge API route handlers have the same function signature as Edge Middleware, meaning the two arguments they receive are of types NextRequest and NextFetchEvent. According to the docs, the only thing that needs to be added to an API route to use the Edge runtime is the following code:
export const config = {
runtime: "experimental-edge",
};This example demonstrates that this does not always work as expected. The API route can silently fall into running in the Nodejs runtime instead, thus changing the argument types to NextRequest and NextResponse. Inspecting the console output after making a request to localhost:3000/api/edge shows that the received arguments are indead extended from IncomingMessage and ServerResponse.
- Install deps:
yarn - Check Nextjs version:
yarn why next - Start dev server:
yarn dev - Review console output, should have warning for experimental Nextjs feature (images), verifying the server is ^v12.2.0. Missing is a warning about experimental edge runtime.
- Visit api route: http://localhost:3000/api/edge
- Review console output, should be following shape:
{
req: IncomingMessage {
...
},
event: ServerResponse {
...
},
url: '/api/edge'
}