intrepid_core/extract/
message_meta_json.rs

1use crate::{Context, Frame};
2
3use super::{Extractor, Message, MessageFrameError};
4
5/// Extracts a JSON-serializable type from a message frame's meta.
6#[derive(Debug, Clone, PartialEq, Eq)]
7pub struct MessageMetaJson<T>(pub T);
8
9impl<T, State> Extractor<State> for MessageMetaJson<T>
10where
11    T: serde::de::DeserializeOwned,
12{
13    type Error = MessageFrameError;
14
15    fn extract(frame: Frame, context: &Context<State>) -> Result<Self, Self::Error>
16    where
17        Self: Sized,
18    {
19        let Message(message_frame) = Message::extract(frame, context)?;
20        let contents: T = serde_json::from_slice(&message_frame.meta)
21            .map_err(MessageFrameError::MalformedJsonMeta)?;
22
23        Ok(Self(contents))
24    }
25}
26
27#[test]
28fn message_meta_json() -> crate::Result<()> {
29    let json = serde_json::to_vec(&vec![1, 2, 3]).expect("Couldn't make a byte vec");
30    let frame = Frame::message("/test", (), json);
31    let context = Context::<()>::default();
32    let MessageMetaJson(message_meta) =
33        MessageMetaJson::<Vec<usize>>::extract_from_frame_and_state(frame, &context)?;
34
35    assert_eq!(message_meta, vec![1, 2, 3]);
36
37    Ok(())
38}
39
40#[test]
41fn wrong_frame_failure() -> crate::Result<()> {
42    use crate::{Error, ExtractorError};
43
44    let context = Context::<()>::default();
45    let result =
46        MessageMetaJson::<Vec<usize>>::extract_from_frame_and_state(Frame::default(), &context);
47
48    assert!(matches!(
49        result.unwrap_err(),
50        Error::ExtractorError(ExtractorError::MessageFrameError(
51            MessageFrameError::WrongFrame(_)
52        ))
53    ),);
54
55    Ok(())
56}
57
58#[test]
59fn extraction_failed_error() -> crate::Result<()> {
60    use crate::{Error, ExtractorError};
61
62    let frame = Frame::message("/test", (), vec![1, 2, 3]);
63    let context = Context::<()>::default();
64    let result = MessageMetaJson::<Vec<usize>>::extract_from_frame_and_state(frame, &context);
65
66    assert!(matches!(
67        result.unwrap_err(),
68        Error::ExtractorError(ExtractorError::MessageFrameError(
69            MessageFrameError::MalformedJsonMeta(_)
70        ))
71    ),);
72
73    Ok(())
74}
intrepid_core/extract/message_meta_json.rs

intrepid_core/extract/
message_meta_json.rs
