Add trailer property

git/objects/commit.py

@@ -4,7 +4,7 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 import datetime
-from subprocess import Popen
+from subprocess import Popen, PIPE
 from gitdb import IStream
 from git.util import (
     hex_to_bin,
@@ -13,6 +13,7 @@
     finalize_process
 )
 from git.diff import Diffable
+from git.cmd import Git
 
 from .tree import Tree
 from . import base
@@ -39,7 +40,7 @@
 
 # typing ------------------------------------------------------------------
 
-from typing import Any, IO, Iterator, List, Sequence, Tuple, Union, TYPE_CHECKING, cast
+from typing import Any, IO, Iterator, List, Sequence, Tuple, Union, TYPE_CHECKING, cast, Dict
 
 from git.types import PathLike, Literal
 
@@ -315,6 +316,53 @@ def stats(self) -> Stats:
             text = self.repo.git.diff(self.parents[0].hexsha, self.hexsha, '--', numstat=True)
         return Stats._list_from_string(self.repo, text)
 
+    @property
+    def trailers(self) -> Dict:
+        """Get the trailers of the message as dictionary
+
+        Git messages can contain trailer information that are similar to RFC 822
+        e-mail headers (see: https://git-scm.com/docs/git-interpret-trailers).
+
+        This funcions calls ``git interpret-trailers --parse`` onto the message
+        to extract the trailer information. The key value pairs are stripped of
+        leading and trailing whitespaces before they get saved into a dictionary.
+
+        Valid message with trailer:
+
+        .. code-block::
+
+            Subject line
+
+            some body information
+
+            another information
+
+            key1: value1
+            key2 :    value 2 with inner spaces
+
+        dictionary will look like this:
+        .. code-block::
+
+            {
+                "key1": "value1",
+                "key2": "value 2 with inner spaces"
+            }
+
+        :return: Dictionary containing whitespace stripped trailer information
+
+        """
+        d = {}
+        cmd = ['git', 'interpret-trailers', '--parse']
+        proc: Git.AutoInterrupt = self.repo.git.execute(cmd, as_process=True, istream=PIPE)  # type: ignore
+        trailer: str = proc.communicate(str(self.message).encode())[0].decode()
+        if trailer.endswith('\n'):
+            trailer = trailer[0:-1]
+        if trailer != '':
+            for line in trailer.split('\n'):
+                key, value = line.split(':', 1)
+                d[key.strip()] = value.strip()
+        return d
+
     @ classmethod
     def _iter_from_process_or_stream(cls, repo: 'Repo', proc_or_stream: Union[Popen, IO]) -> Iterator['Commit']:
         """Parse out commit information into a list of Commit objects

test-requirements.txt

@@ -1,4 +1,4 @@
-ddt>=1.1.1
+ddt>=1.1.1, !=1.4.3
 mypy
 
 flake8

test/test_commit.py

@@ -4,6 +4,7 @@
 #
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
+import copy
 from datetime import datetime
 from io import BytesIO
 import re
@@ -429,3 +430,48 @@ def test_datetimes(self):
                          datetime(2009, 10, 8, 20, 22, 51, tzinfo=tzoffset(-7200)))
         self.assertEqual(commit.committed_datetime,
                          datetime(2009, 10, 8, 18, 22, 51, tzinfo=utc), commit.committed_datetime)
+
+    def test_trailers(self):
+        KEY_1 = "Hello"
+        VALUE_1 = "World"
+        KEY_2 = "Key"
+        VALUE_2 = "Value with inner spaces"
+
+        # Check if KEY 1 & 2 with Value 1 & 2 is extracted from multiple msg variations
+        msgs = []
+        msgs.append(f"Subject\n\n{KEY_1}: {VALUE_1}\n{KEY_2}: {VALUE_2}\n")
+        msgs.append(f"Subject\n  \nSome body of a function\n \n{KEY_1}: {VALUE_1}\n{KEY_2}: {VALUE_2}\n")
+        msgs.append(f"Subject\n  \nSome body of a function\n\nnon-key: non-value\n\n{KEY_1}: {VALUE_1}\n{KEY_2}: {VALUE_2}\n")
+        msgs.append(f"Subject\n  \nSome multiline\n body of a function\n\nnon-key: non-value\n\n{KEY_1}: {VALUE_1}\n{KEY_2} :      {VALUE_2}\n")
+
+        for msg in msgs:
+            commit = self.rorepo.commit('master')
+            commit = copy.copy(commit)
+            commit.message = msg
+            assert KEY_1 in commit.trailers.keys()
+            assert KEY_2 in commit.trailers.keys()
+            assert commit.trailers[KEY_1] == VALUE_1
+            assert commit.trailers[KEY_2] == VALUE_2
+
+        # Check that trailer stays empty for multiple msg combinations
+        msgs = []
+        msgs.append(f"Subject\n")
+        msgs.append(f"Subject\n\nBody with some\nText\n")
+        msgs.append(f"Subject\n\nBody with\nText\n\nContinuation but\n doesn't contain colon\n")
+        msgs.append(f"Subject\n\nBody with\nText\n\nContinuation but\n only contains one :\n")
+        msgs.append(f"Subject\n\nBody with\nText\n\nKey: Value\nLine without colon\n")
+        msgs.append(f"Subject\n\nBody with\nText\n\nLine without colon\nKey: Value\n")
+
+        for msg in msgs:
+            commit = self.rorepo.commit('master')
+            commit = copy.copy(commit)
+            commit.message = msg
+            assert len(commit.trailers.keys()) == 0
+
+        # check that only the last key value paragraph is evaluated
+        commit = self.rorepo.commit('master')
+        commit = copy.copy(commit)
+        commit.message = f"Subject\n\nMultiline\nBody\n\n{KEY_1}: {VALUE_1}\n\n{KEY_2}: {VALUE_2}\n"
+        assert KEY_1 not in commit.trailers.keys()
+        assert KEY_2 in commit.trailers.keys()
+        assert commit.trailers[KEY_2] == VALUE_2