[BUG] invalid implementation of get_cowboy_config/2

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue? - any spec
• Have you validated the input using an OpenAPI validator (example)? yes
• What's the version of OpenAPI Generator used? v4.3.1
• Have you search for related issues/PRs? yes
• What's the actual output vs expected output? see suggest a fix section
• [Optional] Bounty to sponsor the fix (example)

Description

invalid implementation of get_cowboy_config/2

openapi-generator version

v4.3.1 or the latest docker image

OpenAPI declaration file content or url

any valid declaration

Command line used for generation

docker run --rm -v "${PWD}:/local" openapitools/openapi-generator-cli:v4.3.1 \
           -g erlang-server  -i /local/openapi.yaml -o /local/erlang_server

Steps to reproduce

1. generate an erlang-server
2. check *_server.erl file, notice invalid implementation of get_cowboy_config/2 / get_cowboy_config/3 functions.

Related issues/PRs

none

Suggest a fix

• implementation of get_cowboy_config/2 should look like this:

get_cowboy_config(LogicHandler, ExtraOpts) ->
    DefaultOpts = get_default_opts(LogicHandler),
    DefaultEnv = maps:get(env, DefaultOpts, #{}),
    ExtraEnv = maps:get(env, ExtraOpts, #{}),
    Env = maps:merge(DefaultEnv, ExtraEnv),
    Opts = maps:merge(DefaultOpts, ExtraOpts),
    maps:put(env, Env, Opts).

• remove get_cowboy_config/3 and store_key/3 local functions
• change default value for cowboy_extra_opts from an empty list ([]) to an empty map (#{})

  ExtraOpts = maps:get(cowboy_extra_opts, Params, #{}),

• add cowboy_extra_opts to the *_server:start/2 spec definition:

-spec start( ID :: any(), #{
    ip                => inet:ip_address(),
    port              => inet:port_number(),
    logic_handler     => module(),
    net_opts          => [],
    cowboy_extra_opts => cowboy:opts()
}) -> {ok, pid()} | {error, any()}.

Generate an erlang-server with the provided Docker command and inspect the generated *_server.erl file, focusing on get_cowboy_config/2, get_cowboy_config/3, and store_key/3. Compare the generated functions and start/2 specification with the requested behavior; done means the configuration uses map-based cowboy_extra_opts and the generated Erlang code is valid.