[Rust][Bounty] Issues with client code generation.

[seunlanlege]

Description

The generated client code for rust has a few problems:

• It uses the deprecated futures v0.1, when it should use the newer futures v0.3
• The return types of the api methods aren't strongly typed:

Box<dyn Future<Item = ::std::collections::HashMap<String, serde_json::Value>, Error = Error<serde_json::Value>>>

The models are properly generated but the return type of the methods don't reference the generated models at all.

• Some models aren't generated at all when defined as such in the schema:

openapi-generator version

openapi-generator-cli 5.0.0-SNAPSHOT
  commit : 46216cd
  built  : 2020-04-28T13:03:54Z
  source : https://github.com/openapitools/openapi-generator
  docs   : https://openapi-generator.tech/

OpenAPI declaration file content or url

https://api.slack.com/specs/openapi/v2/slack_web.json

Command line used for generation

java -jar ~/Downloads/openapi.jar generate -g rust -i https://api.slack.com/specs/openapi/v2/slack_web.json -o rust

Steps to reproduce

run the command above

Related issues/PRs

Suggest a fix/enhancement

• The generated client code should use the reqwest crate with async/await.
• Change the api for methods from:

pub trait UsersApi {
    fn users_conversations(&self, params: UsersConversationsParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_delete_photo(&self, params: UsersDeletePhotoParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_get_presence(&self, params: UsersGetPresenceParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_identity(&self, params: UsersIdentityParams) -> Result<serde_json::Value, Error>;
    fn users_info(&self, params: UsersInfoParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_list(&self, params: UsersListParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_lookup_by_email(&self, params: UsersLookupByEmailParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_profile_get(&self, params: UsersProfileGetParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_profile_set(&self, params: UsersProfileSetParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_set_active(&self, params: UsersSetActiveParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_set_photo(&self, params: UsersSetPhotoParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
    fn users_set_presence(&self, params: UsersSetPresenceParams) -> Result<::std::collections::HashMap<String, serde_json::Value>, Error>;
}

to:

pub async fn conversations(config: &Configuration, params: UsersConversationsParams) -> Result;
pub async fn delete_photo(config: &Configuration, params: UsersDeletePhotoParams) -> Result;
pub async fn get_presence(config: &Configuration, params: UsersGetPresenceParams) -> Result;
pub async fn identity(config: &Configuration, params: UsersIdentityParams) -> Result;
pub async fn info(config: &Configuration, params: UsersInfoParams) -> Result;
pub async fn list(config: &Configuration, params: UsersListParams) -> Result;
pub async fn lookup_by_email(config: &Configuration, params: UsersLookupByEmailParams) -> Result;
pub async fn profile_get(config: &configuration, params: UsersProfileGetParams) -> Result;
pub async fn profile_set(config: &Configuration, params: UsersProfileSetParams) -> Result;
pub async fn set_active(config: &Configuration, params: UsersSetActiveParams) -> Result;
pub async fn set_photo(config: &Configuration, params: UsersSetPhotoParams) -> Result;
pub async fn set_presence(config: &Configuration, params: UsersSetPresenceParams) -> Result;

• Error and sucess return types should be strongly typed.
• Instead of making each param an argument on the method, the generated client code should aggregate the params into a struct that can be passed to the api method. e.g

Instead of:

fn users_list(&self, cursor: Option<&str>, token: Option<&str>, limit: Option<i32>, include_locale: Option<bool>)

do:

#[derive(Default)]
struct UsersListParams {
    cursor: Option<&str>,
    token: Option<&str>,
    limit: Option<i32>,
    include_locale: Option<bool>,
}

fn users_list(&self, params: UsersListParams)

I'm willing to sponsor work on this issue to the tune of $500.
cc @wing328

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[wing328]

The generated client code should use the reqwest crate with async/await.

You can use reqwest by providing the library option:

	library
	    library template (sub-template) to use. (Default: hyper)
	        hyper - HTTP client: Hyper.
	        reqwest - HTTP client: Reqwest.

In CLI, you need to add --library reqwest

[wing328]

Instead of making each param an argument on the method, the generated client code should aggregate the params into a struct that can be passed to the api method. e.g

Some other generators (e.g. PHP, Java (jersey2)) already support x-group-parameters to group method parameters into a single object.

Basically we need to do the same for Rust client generator.

[seunlanlege]

@wing328 any luck that this is picked up soon?

[wing328]

@seunlanlege can you please PM me via Slack?

https://join.slack.com/t/openapi-generator/shared_invite/enQtNzAyNDMyOTU0OTE1LTY5ZDBiNDI5NzI5ZjQ1Y2E5OWVjMjZkYzY1ZGM2MWQ4YWFjMzcyNDY5MGI4NjQxNDBiMTlmZTc5NjY2ZTQ5MGM

[wing328]

Instead of making each param an argument on the method, the generated client code should aggregate the params into a struct that can be passed to the api method. e.g

Done via #6230

[imp]

It seems that params structures as well as their fields generated by #6230 are private and hence are not usable :(

[wing328]

@imp that's fixed by #6381. Please give the latest master a try.

[wing328]

Change the api for methods from:

Please use the option --remove-operation-id-prefix

Remove prefix of operationId, e.g. config_getId => getId

[imp]

Still no dice. The *Params structures are public now, however they are located in the private module and are not re-exported from there alongside the trait and API client. So still no access to them from outside of the generated crate.

[wing328]

@imp do you mind showing the error message you got when using the *Params structures?

[imp]

@wing328 Here we go:

    Checking storage v1.0.0 (/xxx/out/rust-client)
error[E0432]: unresolved import `storage::apis::ListParams`
 --> examples/disk.rs:7:5
  |
7 | use storage::apis::ListParams;
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^ no `ListParams` in `apis`

error[E0603]: module `disks_api` is private
  --> examples/disk.rs:8:20
   |
8  | use storage::apis::disks_api::ListParams;
   |                    ^^^^^^^^^ private module
   |
note: the module `disks_api` is defined here
  --> /xxx/out/rust-client/src/apis/mod.rs:35:1
   |
35 | mod disks_api;
   | ^^^^^^^^^^^^^^

So the ListParams is not re-exported from storage::apis and hence cannot be used from there (line 7). And it also cannot be used from disks_api, where it is defined, since the disks_api module is private (line 8).

[wing328]

@imp thanks for the info. I'll take another look tomorrow.