git2_time_chrono_ext/
git2_time_chrono_ext.rs

1use anyhow::*;
2use chrono::TimeZone;
3
4/// An extension trait to convert `git2::Time` to `chrono::DateTime`.
5/// # Examples
6/// ```no_run
7/// use git2_time_chrono_ext::Git2TimeChronoExt;
8///
9/// // Print `git2::Time` to `stdout`.
10/// fn print_git2_time(time: git2::Time) {
11///   println!("{}", time.to_local_date_time().unwrap());
12/// }
13///
14/// // Convert `git2::Time` to `Stirng` in the specified format.
15/// fn git2_time_to_string(time: git2::Time) -> String {
16///   time.to_local_date_time().unwrap().format("%Y-%m-%d %H:%M").to_string()
17/// }
18/// ```
19pub trait Git2TimeChronoExt {
20    /// Convert [`git2::Time`] to [`chrono::DateTime<chrono::FixedOffset>`].
21    ///
22    /// This is useful when the original timezone in the [`git2::Time`] is needed.
23    /// # Examples
24    /// ```
25    /// use git2_time_chrono_ext::Git2TimeChronoExt;
26    ///
27    /// // The Eastern Hemisphere time zone.
28    /// let east_time = git2::Time::new(1745693791, 540);
29    /// let east_datetime = east_time.to_date_time();
30    /// assert!(east_datetime.is_ok());
31    /// assert_eq!(east_datetime.unwrap().to_string(), "2025-04-27 03:56:31 +09:00");
32    /// ```
33    /// ```
34    /// # use git2_time_chrono_ext::Git2TimeChronoExt;
35    /// // The Western Hemisphere time zone.
36    /// let west_time = git2::Time::new(1745196130, -420);
37    /// let west_datetime = west_time.to_date_time();
38    /// assert!(west_datetime.is_ok());
39    /// assert_eq!(west_datetime.unwrap().to_string(), "2025-04-20 17:42:10 -07:00");
40    /// ```
41    fn to_date_time(&self) -> anyhow::Result<chrono::DateTime<chrono::FixedOffset>>;
42
43    /// Convert [`git2::Time`] to [`chrono::DateTime`] in the specified time zone.
44    /// # Examples
45    /// ```
46    /// use git2_time_chrono_ext::Git2TimeChronoExt;
47    ///
48    /// let time = git2::Time::new(1745196130, -420);
49    /// let utc_datetime = time.to_date_time_in(&chrono::Utc);
50    /// assert_eq!(utc_datetime.unwrap().to_string(), "2025-04-21 00:42:10 UTC");
51    /// ```
52    fn to_date_time_in<Tz: chrono::TimeZone>(
53        &self,
54        tz: &Tz,
55    ) -> anyhow::Result<chrono::DateTime<Tz>>;
56
57    /// Convert [`git2::Time`] to [`chrono::DateTime`] in the local time zone.
58    /// This function is a shorthand of:
59    /// ```
60    /// # use git2_time_chrono_ext::Git2TimeChronoExt;
61    /// # fn to_local(time: git2::Time) -> anyhow::Result<chrono::DateTime<chrono::Local>> {
62    /// time.to_date_time_in(&chrono::Local)
63    /// # }
64    /// ```
65    fn to_local_date_time(&self) -> anyhow::Result<chrono::DateTime<chrono::Local>>;
66}
67
68impl Git2TimeChronoExt for git2::Time {
69    fn to_date_time(&self) -> anyhow::Result<chrono::DateTime<chrono::FixedOffset>> {
70        let Some(tz) = chrono::FixedOffset::east_opt(self.offset_minutes() * 60) else {
71            bail!("Invalid TimeZone {}", self.offset_minutes());
72        };
73        match tz.timestamp_opt(self.seconds(), 0) {
74            chrono::MappedLocalTime::Single(datetime) => Ok(datetime),
75            chrono::MappedLocalTime::Ambiguous(_, latest) => Ok(latest),
76            chrono::MappedLocalTime::None => bail!(
77                "Time {} isn't mappable to {}",
78                self.seconds(),
79                self.offset_minutes()
80            ),
81        }
82    }
83
84    fn to_date_time_in<Tz: chrono::TimeZone>(
85        &self,
86        tz: &Tz,
87    ) -> anyhow::Result<chrono::DateTime<Tz>> {
88        self.to_date_time()
89            .map(|datetime| datetime.with_timezone(tz))
90    }
91
92    fn to_local_date_time(&self) -> anyhow::Result<chrono::DateTime<chrono::Local>> {
93        self.to_date_time_in(&chrono::Local)
94    }
95}
96
97#[cfg(test)]
98mod tests {
99    use super::*;
100
101    #[test]
102    fn to_date_time_offset_invalid() {
103        let time = git2::Time::new(0, 100_000);
104        let datetime = time.to_date_time();
105        assert!(datetime.is_err());
106        assert_eq!(datetime.unwrap_err().to_string(), "Invalid TimeZone 100000");
107    }
108}
git2_time_chrono_ext/git2_time_chrono_ext.rs

git2_time_chrono_ext/
git2_time_chrono_ext.rs
