vercel_lambda 0.2.0

Rust bindings for Vercel Lambdas
Documentation 
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

//! Response types

use http::{
	header::{HeaderMap, HeaderValue},
	Response,
};
use serde::ser::{Error as SerError, SerializeMap, Serializer};
use serde_derive::Serialize;

use crate::body::Body;

/// Representation of a Vercel Lambda response
#[derive(Serialize, Debug)]
#[serde(rename_all = "camelCase")]
pub(crate) struct VercelResponse {
	pub status_code: u16,
	#[serde(
		skip_serializing_if = "HeaderMap::is_empty",
		serialize_with = "serialize_headers"
	)]
	pub headers: HeaderMap<HeaderValue>,
	#[serde(skip_serializing_if = "Option::is_none")]
	pub body: Option<Body>,
	#[serde(skip_serializing_if = "Option::is_none")]
	pub encoding: Option<String>,
}

impl Default for VercelResponse {
	fn default() -> Self {
		Self {
			status_code: 200,
			headers: Default::default(),
			body: Default::default(),
			encoding: Default::default(),
		}
	}
}

fn serialize_headers<S>(headers: &HeaderMap<HeaderValue>, serializer: S) -> Result<S::Ok, S::Error>
where
	S: Serializer,
{
	let mut map = serializer.serialize_map(Some(headers.keys_len()))?;
	for key in headers.keys() {
		let map_value = headers[key].to_str().map_err(S::Error::custom)?;
		map.serialize_entry(key.as_str(), map_value)?;
	}
	map.end()
}

impl<T> From<Response<T>> for VercelResponse
where
	T: Into<Body>,
{
	fn from(value: Response<T>) -> Self {
		let (parts, bod) = value.into_parts();
		let (encoding, body) = match bod.into() {
			Body::Empty => (None, None),
			b @ Body::Text(_) => (None, Some(b)),
			b @ Body::Binary(_) => (Some("base64".to_string()), Some(b)),
		};
		VercelResponse {
			status_code: parts.status.as_u16(),
			body,
			headers: parts.headers,
			encoding,
		}
	}
}

/// A conversion of self into a `Response`
///
/// Implementations for `Response<B> where B: Into<Body>`,
/// `B where B: Into<Body>` and `serde_json::Value` are provided
/// by default
///
/// # example
///
/// ```rust
/// use vercel_lambda::{Body, IntoResponse, Response};
///
/// assert_eq!(
///   "hello".into_response().body(),
///   Response::new(Body::from("hello")).body()
/// );
/// ```
pub trait IntoResponse {
	/// Return a translation of `self` into a `Response<Body>`
	fn into_response(self) -> Response<Body>;
}

impl<B> IntoResponse for Response<B>
where
	B: Into<Body>,
{
	fn into_response(self) -> Response<Body> {
		let (parts, body) = self.into_parts();
		Response::from_parts(parts, body.into())
	}
}

impl<B> IntoResponse for B
where
	B: Into<Body>,
{
	fn into_response(self) -> Response<Body> {
		Response::new(self.into())
	}
}

impl IntoResponse for serde_json::Value {
	fn into_response(self) -> Response<Body> {
		Response::builder()
			.header(http::header::CONTENT_TYPE, "application/json")
			.body(
				serde_json::to_string(&self)
					.expect("unable to serialize serde_json::Value")
					.into(),
			)
			.expect("unable to build http::Response")
	}
}