git2_time_chrono_ext/
git2_time_chrono_ext.rs

1use crate::Error;
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::{Error, 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///
19/// // Convert `git2::Time` to ISO 8601 (RFC 3339) string.
20/// fn git2_time_to_rfc3339(time: &git2::Time) -> Result<String, Error> {
21///   Ok(time.to_date_time_in(&chrono::Utc)?.to_rfc3339())
22/// }
23/// ```
24pub trait Git2TimeChronoExt {
25    /// Convert [`git2::Time`] to [`chrono::DateTime`]
26    /// retaining the original timezone.
27    /// # Examples
28    /// ```
29    /// use git2_time_chrono_ext::Git2TimeChronoExt;
30    ///
31    /// // The Eastern Hemisphere time zone.
32    /// let east_time = git2::Time::new(1745693791, 540);
33    /// let east_datetime = east_time.to_date_time();
34    /// assert!(east_datetime.is_ok());
35    /// assert_eq!(east_datetime.unwrap().to_string(), "2025-04-27 03:56:31 +09:00");
36    /// ```
37    /// ```
38    /// # use git2_time_chrono_ext::Git2TimeChronoExt;
39    /// // The Western Hemisphere time zone.
40    /// let west_time = git2::Time::new(1745196130, -420);
41    /// let west_datetime = west_time.to_date_time();
42    /// assert!(west_datetime.is_ok());
43    /// assert_eq!(west_datetime.unwrap().to_string(), "2025-04-20 17:42:10 -07:00");
44    /// ```
45    fn to_date_time(&self) -> Result<chrono::DateTime<chrono::FixedOffset>, Error>;
46
47    /// Convert [`git2::Time`] to [`chrono::DateTime`]
48    /// in the specified [`chrono::TimeZone`].
49    /// # Examples
50    /// ```
51    /// use git2_time_chrono_ext::Git2TimeChronoExt;
52    ///
53    /// let time = git2::Time::new(1745196130, -420);
54    /// let utc_datetime = time.to_date_time_in(&chrono::Utc);
55    /// assert_eq!(utc_datetime.unwrap().to_string(), "2025-04-21 00:42:10 UTC");
56    /// ```
57    fn to_date_time_in<Tz: chrono::TimeZone>(&self, tz: &Tz)
58    -> Result<chrono::DateTime<Tz>, Error>;
59
60    /// Convert [`git2::Time`] to [`chrono::DateTime`] in the local time zone.
61    /// This function is a shorthand of:
62    /// ```
63    /// # use git2_time_chrono_ext::Git2TimeChronoExt;
64    /// # fn to_local(time: git2::Time) -> Result<chrono::DateTime<chrono::Local>, git2_time_chrono_ext::Error> {
65    /// time.to_date_time_in(&chrono::Local)
66    /// # }
67    /// ```
68    fn to_local_date_time(&self) -> Result<chrono::DateTime<chrono::Local>, Error>;
69
70    /// [`to_date_time`][Git2TimeChronoExt::to_date_time] returns
71    /// the latest time when the given time is ambiguous.
72    /// This function is useful when you want to handle ambiguous time.
73    /// Please see [`chrono::MappedLocalTime`] for more details.
74    /// # Examples
75    /// ```
76    /// use git2_time_chrono_ext::Git2TimeChronoExt;
77    /// use chrono::MappedLocalTime;
78    ///
79    /// let time = git2::Time::new(1745196130, -420);
80    /// let mapped = time.to_date_time_opt().unwrap();
81    /// if let MappedLocalTime::Single(datetime) = mapped {
82    ///     assert_eq!(datetime.to_string(), "2025-04-20 17:42:10 -07:00");
83    /// } else {
84    ///     panic!("should be Single");
85    /// }
86    /// ```
87    fn to_date_time_opt(
88        &self,
89    ) -> Result<chrono::MappedLocalTime<chrono::DateTime<chrono::FixedOffset>>, Error>;
90}
91
92impl Git2TimeChronoExt for git2::Time {
93    fn to_date_time_opt(
94        &self,
95    ) -> Result<chrono::MappedLocalTime<chrono::DateTime<chrono::FixedOffset>>, Error> {
96        let Some(tz) = chrono::FixedOffset::east_opt(self.offset_minutes() * 60) else {
97            return Err(Error::InvalidTimeZone {
98                offset_minutes: self.offset_minutes(),
99            });
100        };
101        Ok(tz.timestamp_opt(self.seconds(), 0))
102    }
103
104    fn to_date_time(&self) -> Result<chrono::DateTime<chrono::FixedOffset>, Error> {
105        match self.to_date_time_opt()? {
106            chrono::MappedLocalTime::Single(datetime) => Ok(datetime),
107            chrono::MappedLocalTime::Ambiguous(_, latest) => Ok(latest),
108            chrono::MappedLocalTime::None => Err(Error::TimeNotMappable { time: *self }),
109        }
110    }
111
112    fn to_date_time_in<Tz: chrono::TimeZone>(
113        &self,
114        tz: &Tz,
115    ) -> Result<chrono::DateTime<Tz>, Error> {
116        self.to_date_time()
117            .map(|datetime| datetime.with_timezone(tz))
118    }
119
120    fn to_local_date_time(&self) -> Result<chrono::DateTime<chrono::Local>, Error> {
121        self.to_date_time_in(&chrono::Local)
122    }
123}
124
125#[cfg(test)]
126mod tests {
127    use super::*;
128
129    #[test]
130    fn to_date_time_offset_invalid() {
131        let time = git2::Time::new(0, 100_000);
132        let result = time.to_date_time();
133        assert!(result.is_err());
134        let err = result.unwrap_err();
135        assert!(matches!(
136            err,
137            Error::InvalidTimeZone {
138                offset_minutes: 100_000
139            }
140        ));
141    }
142
143    #[test]
144    fn to_date_time_not_mappable() {
145        let time = git2::Time::new(i64::MAX, 0);
146        let result = time.to_date_time();
147        assert!(result.is_err());
148        let err = result.unwrap_err();
149        assert!(matches!(err, Error::TimeNotMappable { .. }));
150    }
151
152    #[test]
153    fn to_date_time_opt_none() {
154        use chrono::MappedLocalTime;
155        let time = git2::Time::new(i64::MAX, 0);
156        let mapped = time.to_date_time_opt().unwrap();
157        assert!(matches!(mapped, MappedLocalTime::None));
158    }
159}
git2_time_chrono_ext/git2_time_chrono_ext.rs

git2_time_chrono_ext/
git2_time_chrono_ext.rs
