[nodejs-server] swagger-tools:router cannot find generated handler due to CapitalCase operationId value in swagger.yaml

Description

After starting a nodejs-server using NODE_ENV=development DEBUG=* npm start and making a request, swagger-tools:middleware:router informs me that the handler is missing. This issue is caused by the operationId in the swagger.yaml having a value that is CapitalCase when I think it should be camelCase. So the router is looking for a CapitalCase handler name but all the handlers are defined with camelCase.

// Example generated Handler code -- it is camelCase
module.exports.getUser = function getUser (req, res, next) {
  Users.getUser(req.swagger.params, res, next);
};  

  // See third line: the router is looking for "GetUser" as CapitalCase
  swagger-tools:middleware:router GET /api/users/abc +0ms
  swagger-tools:middleware:router   Will process: yes +0ms
  swagger-tools:middleware:router   Route handler: Users_GetUser +0ms
  swagger-tools:middleware:router     Missing: yes +1ms
  swagger-tools:middleware:router     Ignored: no +0ms
  swagger-tools:middleware:router     Using mock: yes +0ms

I have confirmed that changing the handler name to CapitalCase allows the router to find it. Alternatively, I also tried changing the operationId value in swagger.yaml to camelCase which is another way to fix the problem.

It looks like the default generated handlers are meant to be runnable as a basic mock when swagger-tools router mocking is turned off, but the router can't find them due to casing issue described above.

Swagger-codegen version

using docker image: swaggerapi/swagger-codegen-cli:latest @ v2.4.0-SNAPSHOT

Suggest a fix/enhancement

It seems like the swagger-codegen should be writing the swagger.yaml with camelCase like operationId: getUser, not CapitalCase.

Start by reproducing the request with NODE_ENV=development DEBUG=* npm start, then compare the operationId in swagger.yaml with the generated JavaScript handler name. Confirm that the router resolves the handler when casing matches, and add or update a regression test if the repository provides one.