armature-lambda 0.2.0

AWS Lambda runtime adapter for Armature applications
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
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167

//! Lambda response conversion.

use bytes::Bytes;
use lambda_http::{Body, Response};
use std::collections::HashMap;

/// Lambda HTTP response.
pub struct LambdaResponse {
    /// Status code.
    pub status: u16,
    /// Response headers.
    pub headers: HashMap<String, String>,
    /// Response body.
    pub body: Bytes,
    /// Whether body is base64 encoded.
    pub is_base64: bool,
}

impl LambdaResponse {
    /// Create a new response.
    pub fn new(status: u16, body: impl Into<Bytes>) -> Self {
        Self {
            status,
            headers: HashMap::new(),
            body: body.into(),
            is_base64: false,
        }
    }

    /// Create an OK response.
    pub fn ok(body: impl Into<Bytes>) -> Self {
        Self::new(200, body)
    }

    /// Create a JSON response.
    pub fn json<T: serde::Serialize>(data: &T) -> Result<Self, serde_json::Error> {
        let body = serde_json::to_vec(data)?;
        Ok(Self::new(200, body).header("content-type", "application/json"))
    }

    /// Create an error response.
    pub fn error(status: u16, message: impl Into<String>) -> Self {
        let body = serde_json::json!({
            "error": message.into()
        });
        Self::new(status, serde_json::to_vec(&body).unwrap_or_default())
            .header("content-type", "application/json")
    }

    /// Create a not found response.
    pub fn not_found() -> Self {
        Self::error(404, "Not Found")
    }

    /// Create an internal server error response.
    pub fn internal_error(message: impl Into<String>) -> Self {
        Self::error(500, message)
    }

    /// Add a header.
    pub fn header(mut self, name: impl Into<String>, value: impl Into<String>) -> Self {
        self.headers.insert(name.into(), value.into());
        self
    }

    /// Set content type.
    pub fn content_type(self, content_type: impl Into<String>) -> Self {
        self.header("content-type", content_type)
    }

    /// Mark body as base64 encoded.
    pub fn base64(mut self) -> Self {
        self.is_base64 = true;
        self
    }

    /// Convert to lambda_http::Response.
    pub fn into_lambda_response(self) -> Response<Body> {
        let mut builder = Response::builder().status(self.status);

        for (name, value) in &self.headers {
            builder = builder.header(name, value);
        }

        let body = if self.is_base64 {
            Body::Binary(self.body.to_vec())
        } else if let Ok(s) = String::from_utf8(self.body.to_vec()) {
            Body::Text(s)
        } else {
            Body::Binary(self.body.to_vec())
        };

        builder.body(body).unwrap_or_else(|_| {
            Response::builder()
                .status(500)
                .body(Body::Text("Internal Server Error".to_string()))
                .unwrap()
        })
    }
}

impl Default for LambdaResponse {
    fn default() -> Self {
        Self::new(200, Bytes::new())
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn utf8_body_maps_to_text() {
        let resp = LambdaResponse::ok("hello world");
        let lambda = resp.into_lambda_response();
        assert_eq!(lambda.status(), 200);
        match lambda.body() {
            Body::Text(s) => assert_eq!(s, "hello world"),
            other => panic!("expected text body, got {other:?}"),
        }
    }

    #[test]
    fn base64_flag_forces_binary_body() {
        let resp = LambdaResponse::ok("hello").base64();
        let lambda = resp.into_lambda_response();
        match lambda.body() {
            Body::Binary(b) => assert_eq!(b, b"hello"),
            other => panic!("expected binary body, got {other:?}"),
        }
    }

    #[test]
    fn non_utf8_body_maps_to_binary() {
        let resp = LambdaResponse::new(200, Bytes::from_static(&[0xff, 0xfe, 0x00]));
        let lambda = resp.into_lambda_response();
        match lambda.body() {
            Body::Binary(b) => assert_eq!(b, &[0xff, 0xfe, 0x00]),
            other => panic!("expected binary body, got {other:?}"),
        }
    }

    #[test]
    fn headers_are_forwarded() {
        let resp = LambdaResponse::json(&serde_json::json!({ "ok": true })).unwrap();
        let lambda = resp.into_lambda_response();
        assert_eq!(
            lambda
                .headers()
                .get("content-type")
                .and_then(|v| v.to_str().ok()),
            Some("application/json")
        );
    }

    #[test]
    fn error_response_sets_status_and_json() {
        let resp = LambdaResponse::not_found();
        assert_eq!(resp.status, 404);
        let lambda = resp.into_lambda_response();
        assert_eq!(lambda.status(), 404);
        match lambda.body() {
            Body::Text(s) => assert!(s.contains("Not Found")),
            other => panic!("expected text body, got {other:?}"),
        }
    }
}