Add option to retain the API Gateway stage in the URL passed to fastify

[thorhj]

On my team we have an API Gateway with a stage that we want to include in the URL passed to fastify. E.g. we have the stage stage with a resource my-resource, we would have this route in fastify:

app.get("/stage/my-resource", ...);

Currently the "stage" part is stripped from the URL:

    let url = event.path || event.rawPath || '/' // seen rawPath for HTTP-API
    // NOTE: if used directly via API Gateway domain and /stage
    if (event.requestContext && event.requestContext.stage && event.requestContext.resourcePath &&
        (url).indexOf(`/${event.requestContext.stage}/`) === 0 &&
        event.requestContext.resourcePath.indexOf(`/${event.requestContext.stage}/`) !== 0) {
      url = url.substring(event.requestContext.stage.length + 1)
    }

This PR adds a new option called retainStage that will make sure to retain the stage part of the URL.

This extends the public API! I have documented the change in README.md and updated the TS definition. The change is non-breaking.

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

npm run test

...
Suites:   ​3 passed​, ​3 of 3 completed​
Asserts:  ​​​222 passed​, ​of 222​

npm run performance

aws-serverless-express x 10,951 ops/sec ±11.14% (75 runs sampled)
(node:31068) [FSTDEP011] FastifyDeprecation: Variadic listen method is deprecated. Please use ".listen(optionsObject)" instead. The variadic signature will be removed in `fastify@5`.
(Use `node --trace-warnings ...` to show where the warning was created)
aws-serverless-fastify x 15,076 ops/sec ±2.88% (89 runs sampled)
serverless-http x 32,611 ops/sec ±6.82% (83 runs sampled)
aws-lambda-fastify x 43,800 ops/sec ±2.82% (81 runs sampled)
aws-lambda-fastify (serializeLambdaArguments : true) x 44,551 ops/sec ±1.99% (85 runs sampled)
aws-lambda-fastify (decorateRequest : false) x 43,636 ops/sec ±3.34% (81 runs sampled)
Fastest is aws-lambda-fastify (serializeLambdaArguments : true),aws-lambda-fastify,aws-lambda-fastify (decorateRequest : false)

[adrai]

thank you for your contribution... it's included in v3.3.0

[thorhj]

Cool, thanks @adrai
When will v3.3.0 be released you think?

[adrai]

already published

[thorhj]

Ah yes, was looking at the Github Releases. Thanks!