GitRepository: add describe() method

Change GitRepository.find_tag() to its original simple version.

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>

3 files changed, 64 insertions, 22 deletions

diff --git a/gbp/git/repository.py b/gbp/git/repository.py
index 77c7cf7a..31a4eb49 100644
--- a/gbp/git/repository.py
+++ b/gbp/git/repository.py
@@ -624,37 +624,56 @@ class GitRepository(object):
         out, ret = self._git_getoutput('tag', [ '-l', tag ])
         return [ False, True ][len(out)]
 
-    def find_tag(self, commit, pattern=None, longfmt=False, always=False):
+    def describe(self, commitish, pattern=None, longfmt=False, always=False,
+                 abbrev=None):
         """
-        Find the closest tag to a given commit
+        Describe commit, relative to the latest tag reachable from it.
 
-        @param commit: the commit to describe
-        @type commit: C{str}
+        @param commitish: the commit-ish to describe
+        @type commitish: C{str}
         @param pattern: only look for tags matching I{pattern}
         @type pattern: C{str}
-        @param longfmt: return the tag in the long format
+        @param longfmt: describe the commit in the long format
         @type longfmt: C{bool}
-        @param always: return commit sha1 as fallback
+        @param always: return commit sha1 as fallback if no tag is found
         @type always: C{bool}
-        @return: the found tag
+        @param abbrev: abbreviate sha1 to given length instead of the default
+        @type abbrev: None or C{long}
+        @return: tag name plus/or the abbreviated sha1
         @rtype: C{str}
         """
         args = GitArgs()
         args.add_true(pattern, ['--match' , pattern])
-        if not longfmt and not always:
-            args.add('--abbrev=0')
-        else:
-            args.add_true(longfmt, '--long')
-            args.add_true(always, '--always')
-        args.add(commit)
+        args.add_true(longfmt, '--long')
+        # 'long' and 'abbrev=0' are incompatible, behave similar to
+        # 'always' and 'abbrev=0'
+        if longfmt and abbrev == 0:
+            args.add('--abbrev=40')
+        elif abbrev is not None:
+            args.add('--abbrev=%s' % abbrev)
+        args.add_true(always, '--always')
+        args.add(commitish)
 
         tag, err, ret = self._git_inout('describe', args.args,
                                         capture_stderr=True)
         if ret:
-            raise GitRepositoryError("Can't find tag for %s. Git error: %s" % \
-                                         (commit, err.strip()))
+            raise GitRepositoryError("Can't describe %s. Git error: %s" % \
+                                         (commitish, err.strip()))
         return tag.strip()
 
+    def find_tag(self, commit, pattern=None):
+        """
+        Find the closest tag to a given commit
+
+        @param commit: the commit to describe
+        @type commit: C{str}
+        @param pattern: only look for tags matching I{pattern}
+        @type pattern: C{str}
+        @return: the found tag
+        @rtype: C{str}
+        """
+        return self.describe(commit, pattern, abbrev=0)
+
     def get_tags(self, pattern=None):
         """
         List tags
diff --git a/gbp/scripts/buildpackage_rpm.py b/gbp/scripts/buildpackage_rpm.py
index 33c5f447..831d85f2 100755
--- a/gbp/scripts/buildpackage_rpm.py
+++ b/gbp/scripts/buildpackage_rpm.py
@@ -603,10 +603,10 @@ def main(argv):
                                    'GBP_SHA1': sha})()
         else:
             try:
-                tree_name = repo.find_tag(tree, longfmt=True, always=True)
+                tree_name = repo.describe(tree, longfmt=True, always=True)
             except GitRepositoryError:
                 # If tree is not commit-ish, expect it to be from current HEAD
-                tree_name = repo.find_tag('HEAD', longfmt=True, always=True) +\
+                tree_name = repo.describe('HEAD', longfmt=True, always=True) +\
                             '-dirty'
         # Put 'VCS:' tag to .spec
         spec.set_tag('VCS', None,
diff --git a/tests/test_GitRepository.py b/tests/test_GitRepository.py
index 3b6b924b..443c81dc 100644
--- a/tests/test_GitRepository.py
+++ b/tests/test_GitRepository.py
@@ -252,6 +252,33 @@ def test_tag():
     ['tag', 'tag2']
     """
 
+def test_describe():
+    """
+    Describe commit-ish
+
+    Methods tested:
+         - L{gbp.git.GitRepository.describe}
+
+    >>> import gbp.git
+    >>> repo = gbp.git.GitRepository(repo_dir)
+    >>> sha = repo.rev_parse('HEAD')
+    >>> repo.describe('HEAD')
+    'tag2'
+    >>> repo.describe('HEAD', longfmt=True) == 'tag2-0-g%s' % sha[:7]
+    True
+    >>> repo.describe('HEAD', pattern='foo*')
+    Traceback (most recent call last):
+    ...
+    GitRepositoryError: Can't describe HEAD. Git error: fatal: No names found, cannot describe anything.
+    >>> repo.describe('HEAD', pattern='foo*', always=True) == sha[:7]
+    True
+    >>> repo.describe('HEAD', always=True, abbrev=16)
+    'tag2'
+    >>> repo.describe('HEAD', pattern='foo*', always=True, abbrev=16) == sha[:16]
+    True
+    >>> tag = repo.describe('HEAD', longfmt=True, abbrev=16) == 'tag2-0-g%s' % sha[:16]
+    """
+
 def test_find_tag():
     """
     Find tags
@@ -263,14 +290,10 @@ def test_find_tag():
     >>> repo = gbp.git.GitRepository(repo_dir)
     >>> repo.find_tag('HEAD')
     'tag2'
-    >>> repo.find_tag('HEAD', longfmt=True)[:7]
-    'tag2-0-'
     >>> repo.find_tag('HEAD', pattern='foo*')
     Traceback (most recent call last):
     ...
-    GitRepositoryError: Can't find tag for HEAD. Git error: fatal: No names found, cannot describe anything.
-    >>> len(repo.find_tag('HEAD', pattern='foo*', always=True))
-    7
+    GitRepositoryError: Can't describe HEAD. Git error: fatal: No names found, cannot describe anything.
     """
 
 def test_move_tag():