[BUG][RUST-SERVER] doesn't produce compilable code with simple example API

[piersfinlayson]

Description

I have written a simple, sample API, and rust-server generates code which doesn't compile.

Full cargo build output here, but there are three problems:

• models::models::models::TYPE used instead of models::TYPE, e.g.

error[E0603]: module `models` is private
  --> src/lib.rs:77:35
   |
77 |     fn a_post(&self, arg: models::models::models::Arg) -> Box<Future<Item=APostResponse, Error=ApiError>>;

• wrong variable used to log parameter e.g.

error[E0277]: `()` doesn't implement `std::fmt::Display`
   --> src/server/mod.rs:210:173
    |
210 |                         Err(e) => return Box::new(future::ok(Response::new().with_status(StatusCode::BadRequest).with_body(format!("Couldn't parse path parameter arg: {}", e)))),

In this case , e) should be , param_arg)

• invalid FromStr implementation e.g.

error[E0308]: match arms have incompatible types
  --> src/models.rs:42:9
   |
42 | /         match s {
43 | |             "0" => Ok(Arg::_0),
   | |                    ----------- match arm with an incompatible type
44 | |             "1" => Ok(Arg::_1),
45 | |             "2" => Ok(Arg::_2),
46 | |             _ => Err(()),
47 | |         }
   | |_________^ expected enum `std::result::Result`, found struct `models::Ok`
   |
   = note: expected type `std::result::Result<models::Arg, ()>`
              found type `models::Ok`

This might be a little harsh! The problem is that Ok here is models::Ok not Result::Ok.

Commit fixing the compilation errors here.

There are also similar errors with the client and server examples, plus also an extraneous use swagger::auth::Authorization; causing the server example to fail to compile:

error: unused import: `swagger::auth::Authorization`
  --> examples/server_lib/mod.rs:16:5
   |
16 | use swagger::auth::Authorization;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `-D unused-imports` implied by `-D warnings`

Fixes for the client and server examples are in this commit.

openapi-generator version

4.0.0-SNAPSHOT

Using container openapitools/openapi-generator-cli:latest

OpenAPI declaration file content or url

openapi.yaml

Command line used for generation

docker run --rm \
           -v ~/openapi-generator-rust-server-test/openapi_client:/local \
           openapitools/openapi-generator-cli \
           generate \
           -g rust-server \
           -i /local/openapi.yaml \
           -o /local

Steps to reproduce

cd ~
git clone https://github.com/piersfinlayson/openapi-generator-rust-server-test
cd openapi-generator-rust-server-test
docker pull openapitools/openapi-generator-cli
docker run --rm \
           -v ~/openapi-generator-rust-server-test/openapi_client:/local \
           openapitools/openapi-generator-cli \
           generate \
           -g rust-server \
           -i /local/openapi.yaml \
           -o /local
cd openapi_client
cargo build
cargo build --example client
cargo build --example server

Related issues/PRs

None that I can see

Suggest a fix

See above

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[richardwhiuk]

wrong variable used to log parameter

This is fixed by #5490 - the variable's correct, but we should be providing a type that does implement Display so we can provide some detail on why the arg failed to parse.

extraneous use swagger::auth::Authorization;

This is fixed by #2504 - specifically https://github.com/OpenAPITools/openapi-generator/pull/2504/files#diff-222a21abd6957cc26b6f8b495c327837R16-R18

models::models::models::TYPE used instead of models::TYPE, e.g.

This was fixed by some general tidy up in #2504

invalid FromStr implementation e.g.

This is being caused by the clashing Ok model.

#5557 makes some progress to fix this sort of error, but didn't consider those types imported by the prelude such as Result.

I'll add something to that MR to fix this as well.