gix_object/commit/message/
mod.rs

1use std::borrow::Cow;
2
3use crate::{
4    bstr::{BStr, BString, ByteSlice, ByteVec},
5    commit::MessageRef,
6    CommitRef,
7};
8
9///
10pub mod body;
11mod decode;
12
13impl<'a> CommitRef<'a> {
14    /// Return exactly the same message as [`MessageRef::summary()`].
15    pub fn message_summary(&self) -> Cow<'a, BStr> {
16        summary(self.message)
17    }
18
19    /// Return an iterator over message trailers as obtained from the last paragraph of the commit message.
20    /// Maybe empty.
21    pub fn message_trailers(&self) -> body::Trailers<'a> {
22        BodyRef::from_bytes(self.message).trailers()
23    }
24}
25
26/// Convenience methods
27impl<'a> CommitRef<'a> {
28    /// Get an iterator over all `Signed-off-by` trailers in the commit message.
29    /// This is useful for finding who signed off on the commit.
30    pub fn signed_off_by_trailers(&self) -> impl Iterator<Item = body::TrailerRef<'a>> {
31        self.message_trailers().signed_off_by()
32    }
33
34    /// Get an iterator over `Co-authored-by` trailers in the commit message.
35    /// This is useful for squashed commits that contain multiple authors.
36    pub fn co_authored_by_trailers(&self) -> impl Iterator<Item = body::TrailerRef<'a>> {
37        self.message_trailers().co_authored_by()
38    }
39
40    /// Get all authors mentioned in `Signed-off-by` and `Co-authored-by` trailers.
41    /// This is useful for squashed commits that contain multiple authors.
42    /// Returns a Vec of author strings that can include both signers and co-authors.
43    pub fn author_trailers(&self) -> impl Iterator<Item = body::TrailerRef<'a>> {
44        self.message_trailers().authors()
45    }
46
47    /// Get an iterator over all attribution-related trailers
48    /// (`Signed-off-by,` `Co-authored-by`, `Acked-by`, `Reviewed-by`, `Tested-by`).
49    /// This provides a comprehensive view of everyone who contributed to or reviewed the commit.
50    /// Note that the same name may occur multiple times, it's not a unified list.
51    pub fn attribution_trailers(&self) -> impl Iterator<Item = body::TrailerRef<'a>> {
52        self.message_trailers().attributions()
53    }
54}
55
56impl<'a> MessageRef<'a> {
57    /// Parse the given `input` as a message.
58    ///
59    /// Note that this cannot fail as everything will be interpreted as title if there is no body separator.
60    pub fn from_bytes(input: &'a [u8]) -> Self {
61        let (title, body) = decode::message(input);
62        MessageRef { title, body }
63    }
64
65    /// Produce a short commit summary for the message title.
66    ///
67    /// This means the following
68    ///
69    /// * Take the subject line which is delimited by two newlines (\n\n)
70    /// * transform intermediate consecutive whitespace including \r into one space
71    ///
72    /// The resulting summary will have folded whitespace before a newline into spaces and stopped that process
73    /// once two consecutive newlines are encountered.
74    pub fn summary(&self) -> Cow<'a, BStr> {
75        summary(self.title)
76    }
77
78    /// Further parse the body into non-trailer and trailers, which can be iterated from the returned [`BodyRef`].
79    pub fn body(&self) -> Option<BodyRef<'a>> {
80        self.body.map(|b| BodyRef::from_bytes(b))
81    }
82}
83
84pub(crate) fn summary(message: &BStr) -> Cow<'_, BStr> {
85    let message = message.trim();
86    match message.find_byte(b'\n') {
87        Some(mut pos) => {
88            let mut out = BString::default();
89            let mut previous_pos = None;
90            loop {
91                if let Some(previous_pos) = previous_pos {
92                    if previous_pos + 1 == pos {
93                        let len_after_trim = out.trim_end().len();
94                        out.resize(len_after_trim, 0);
95                        break out.into();
96                    }
97                }
98                let message_to_newline = &message[previous_pos.map_or(0, |p| p + 1)..pos];
99
100                if let Some(pos_before_whitespace) = message_to_newline.rfind_not_byteset(b"\t\n\x0C\r ") {
101                    out.extend_from_slice(&message_to_newline[..=pos_before_whitespace]);
102                }
103                out.push_byte(b' ');
104                previous_pos = Some(pos);
105                match message.get(pos + 1..).and_then(|i| i.find_byte(b'\n')) {
106                    Some(next_nl_pos) => pos += next_nl_pos + 1,
107                    None => {
108                        if let Some(slice) = message.get((pos + 1)..) {
109                            out.extend_from_slice(slice);
110                        }
111                        break out.into();
112                    }
113                }
114            }
115        }
116        None => message.as_bstr().into(),
117    }
118}
119
120/// A reference to a message body, further parsed to only contain the non-trailer parts.
121///
122/// See [git-interpret-trailers](https://git-scm.com/docs/git-interpret-trailers) for more information
123/// on what constitutes trailers and not that this implementation is only good for typical sign-off footer or key-value parsing.
124///
125/// Note that we only parse trailers from the bottom of the body.
126#[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]
127pub struct BodyRef<'a> {
128    body_without_trailer: &'a BStr,
129    start_of_trailer: &'a [u8],
130}