1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139

use super::{handle_error, IntoResponse, ResourceError};
#[cfg(feature = "openapi")]
use crate::ResponseSchema;
use crate::{Response, ResponseBody, Success};
use futures_core::future::Future;
use gotham::{
	anyhow::Error,
	hyper::StatusCode,
	mime::{Mime, APPLICATION_JSON}
};
#[cfg(feature = "openapi")]
use openapi_type::{OpenapiSchema, OpenapiType};
use std::{fmt::Debug, pin::Pin};

pub trait IntoResponseError {
	type Err: Debug + Send + 'static;

	fn into_response_error(self) -> Result<Response, Self::Err>;

	#[cfg(feature = "openapi")]
	fn status_codes() -> Vec<StatusCode>;

	#[cfg(feature = "openapi")]
	fn schema(code: StatusCode) -> OpenapiSchema;
}

impl<E> IntoResponseError for E
where
	E: Into<Error>
{
	type Err = serde_json::Error;

	fn into_response_error(self) -> Result<Response, Self::Err> {
		let err: Error = self.into();
		let err: ResourceError = err.into();
		Ok(Response::json(
			StatusCode::INTERNAL_SERVER_ERROR,
			serde_json::to_string(&err)?
		))
	}

	#[cfg(feature = "openapi")]
	fn status_codes() -> Vec<StatusCode> {
		vec![StatusCode::INTERNAL_SERVER_ERROR]
	}

	#[cfg(feature = "openapi")]
	fn schema(code: StatusCode) -> OpenapiSchema {
		assert_eq!(code, StatusCode::INTERNAL_SERVER_ERROR);
		ResourceError::schema()
	}
}

impl<R, E> IntoResponse for Result<R, E>
where
	R: ResponseBody,
	E: Debug + IntoResponseError<Err = serde_json::Error>
{
	type Err = E::Err;

	fn into_response(self) -> Pin<Box<dyn Future<Output = Result<Response, E::Err>> + Send>> {
		match self {
			Ok(r) => Success::from(r).into_response(),
			Err(e) => handle_error(e)
		}
	}

	fn accepted_types() -> Option<Vec<Mime>> {
		Some(vec![APPLICATION_JSON])
	}
}

#[cfg(feature = "openapi")]
impl<R, E> ResponseSchema for Result<R, E>
where
	R: ResponseBody,
	E: Debug + IntoResponseError<Err = serde_json::Error>
{
	fn status_codes() -> Vec<StatusCode> {
		let mut status_codes = E::status_codes();
		status_codes.push(StatusCode::OK);
		status_codes
	}

	fn schema(code: StatusCode) -> OpenapiSchema {
		match code {
			StatusCode::OK => R::schema(),
			code => E::schema(code)
		}
	}
}

#[cfg(test)]
mod test {
	use super::*;
	use crate::response::OrAllTypes;
	use futures_executor::block_on;
	use thiserror::Error;

	#[derive(Debug, Default, Deserialize, Serialize)]
	#[cfg_attr(feature = "openapi", derive(openapi_type::OpenapiType))]
	struct Msg {
		msg: String
	}

	#[derive(Debug, Default, Error)]
	#[error("An Error")]
	struct MsgError;

	#[test]
	fn result_ok() {
		let ok: Result<Msg, MsgError> = Ok(Msg::default());
		let res = block_on(ok.into_response()).expect("didn't expect error response");
		assert_eq!(res.status, StatusCode::OK);
		assert_eq!(res.mime, Some(APPLICATION_JSON));
		assert_eq!(res.full_body().unwrap(), br#"{"msg":""}"#);
	}

	#[test]
	fn result_err() {
		let err: Result<Msg, MsgError> = Err(MsgError);
		let res = block_on(err.into_response()).expect("didn't expect error response");
		assert_eq!(res.status, StatusCode::INTERNAL_SERVER_ERROR);
		assert_eq!(res.mime, Some(APPLICATION_JSON));
		assert_eq!(
			res.full_body().unwrap(),
			format!(r#"{{"error":true,"message":"{}"}}"#, MsgError).as_bytes()
		);
	}

	#[test]
	fn success_accepts_json() {
		assert!(
			<Result<Msg, MsgError>>::accepted_types()
				.or_all_types()
				.contains(&APPLICATION_JSON)
		)
	}
}