newt_core/
session.rs

1use serde::{Deserialize, Serialize};
2use std::fmt;
3use std::str::FromStr;
4use uuid::Uuid;
5
6/// Opaque session identifier — wraps a UUID v4.
7#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
8#[serde(transparent)]
9pub struct SessionId(Uuid);
10
11impl SessionId {
12    pub fn new() -> Self {
13        Self(Uuid::new_v4())
14    }
15
16    pub fn from_uuid(uuid: Uuid) -> Self {
17        Self(uuid)
18    }
19
20    pub fn as_uuid(&self) -> &Uuid {
21        &self.0
22    }
23}
24
25impl Default for SessionId {
26    fn default() -> Self {
27        Self::new()
28    }
29}
30
31impl fmt::Display for SessionId {
32    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
33        self.0.fmt(f)
34    }
35}
36
37impl FromStr for SessionId {
38    type Err = uuid::Error;
39    fn from_str(s: &str) -> Result<Self, Self::Err> {
40        Uuid::from_str(s).map(Self)
41    }
42}
43
44#[cfg(test)]
45mod tests {
46    use super::*;
47
48    #[test]
49    fn generate_unique() {
50        let a = SessionId::new();
51        let b = SessionId::new();
52        assert_ne!(a, b);
53    }
54
55    #[test]
56    fn parse_roundtrip() {
57        let id = SessionId::new();
58        let s = id.to_string();
59        let parsed: SessionId = s.parse().unwrap();
60        assert_eq!(id, parsed);
61    }
62
63    #[test]
64    fn display_is_uuid_format() {
65        let id = SessionId::new();
66        let s = id.to_string();
67        assert_eq!(s.len(), 36);
68        assert_eq!(s.as_bytes()[8], b'-');
69        assert_eq!(s.as_bytes()[13], b'-');
70        assert_eq!(s.as_bytes()[18], b'-');
71        assert_eq!(s.as_bytes()[23], b'-');
72    }
73
74    #[test]
75    fn invalid_string_rejected() {
76        assert!("not-a-uuid".parse::<SessionId>().is_err());
77    }
78
79    #[test]
80    fn serde_roundtrip() {
81        let id = SessionId::new();
82        let json = serde_json::to_string(&id).unwrap();
83        let back: SessionId = serde_json::from_str(&json).unwrap();
84        assert_eq!(id, back);
85    }
86}
newt_core/session.rs

newt_core/
session.rs
