Merge "Look for and process sem-ver pseudo headers in git"

3 files changed, 104 insertions, 4 deletions

diff --git a/doc/source/index.rst b/doc/source/index.rst
index 897f3e5..fa77de1 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -36,6 +36,16 @@ If a given revision is tagged, that's the version.
 If it's not, then we take the last tagged version number and increment it to
 get a minimum target version.
 
+We then walk git history back to the last release. Within each commit we look
+for a sem-ver: pseudo header, and if found parse it looking for keywords.
+Unknown symbols are not an error (so that folk can't wedge pbr or break their
+tree), but we will emit an info level warning message.  Known symbols:
+``feature``, ``api-break``, ``deprecation``, ``bugfix``. A missing
+sem-ver line is equivalent to ``sem-ver: bugfix``. The ``bugfix`` symbol causes
+a patch level increment to the version. The ``feature`` and ``deprecation``
+symbols cause a minor version increment. The ``api-break`` symbol causes a
+major version increment.
+
 If postversioning is in use, we use the resulting version number as the target
 version.
 
diff --git a/pbr/packaging.py b/pbr/packaging.py
index 3f35593..e2fec70 100644
--- a/pbr/packaging.py
+++ b/pbr/packaging.py
@@ -776,6 +776,43 @@ def have_sphinx():
     return _have_sphinx
 
 
+def _get_increment_kwargs(git_dir, tag):
+    """Calculate the sort of semver increment needed from git history.
+
+    Every commit from HEAD to tag is consider for sem-ver metadata lines.
+    See the pbr docs for their syntax.
+
+    :return: a dict of kwargs for passing into SemanticVersion.increment.
+    """
+    result = {}
+    if tag:
+        version_spec = tag + "..HEAD"
+    else:
+        version_spec = "HEAD"
+    changelog = _run_git_command(['log', version_spec], git_dir)
+    header_len = len('    sem-ver:')
+    commands = [line[header_len:].strip() for line in changelog.split('\n')
+                if line.startswith('    sem-ver:')]
+    symbols = set()
+    for command in commands:
+        symbols.update([symbol.strip() for symbol in command.split(',')])
+
+    def _handle_symbol(symbol, symbols, impact):
+        if symbol in symbols:
+            result[impact] = True
+            symbols.discard(symbol)
+    _handle_symbol('bugfix', symbols, 'patch')
+    _handle_symbol('feature', symbols, 'minor')
+    _handle_symbol('deprecation', symbols, 'minor')
+    _handle_symbol('api-break', symbols, 'major')
+    for symbol in symbols:
+        log.info('[pbr] Unknown sem-ver symbol %r' % symbol)
+    # We don't want patch in the kwargs since it is not a keyword argument -
+    # its the default minimum increment.
+    result.pop('patch', None)
+    return result
+
+
 def _get_revno_and_last_tag(git_dir):
     """Return the commit data about the most recent tag.
 
@@ -813,7 +850,7 @@ def _get_version_from_git_target(git_dir, target_version):
         ['log', '-n1', '--pretty=format:%h'], git_dir)
     tag, distance = _get_revno_and_last_tag(git_dir)
     last_semver = version.SemanticVersion.from_pip_string(tag or '0')
-    new_version = last_semver.increment()
+    new_version = last_semver.increment(**_get_increment_kwargs(git_dir, tag))
     if target_version is not None and new_version > target_version:
         raise ValueError(
             "git history requires a target version of %(new)s, but target "
diff --git a/pbr/tests/test_packaging.py b/pbr/tests/test_packaging.py
index 1fe8659..71ce6d3 100644
--- a/pbr/tests/test_packaging.py
+++ b/pbr/tests/test_packaging.py
@@ -73,12 +73,15 @@ class TestRepo(fixtures.Fixture):
              'example@example.com'], self._basedir)
         base._run_cmd(['git', 'add', '.'], self._basedir)
 
-    def commit(self):
+    def commit(self, message_content='test commit'):
         files = len(os.listdir(self._basedir))
         path = self._basedir + '/%d' % files
         open(path, 'wt').close()
         base._run_cmd(['git', 'add', path], self._basedir)
-        base._run_cmd(['git', 'commit', '-m', 'test commit'], self._basedir)
+        base._run_cmd(['git', 'commit', '-m', message_content], self._basedir)
+
+    def uncommit(self):
+        base._run_cmd(['git', 'reset', '--hard', 'HEAD^'], self._basedir)
 
     def tag(self, version):
         base._run_cmd(
@@ -237,6 +240,20 @@ class TestVersions(base.BaseTestCase):
         version = packaging._get_version_from_git()
         self.assertThat(version, matchers.StartsWith('1.2.4.dev1.g'))
 
+    def test_untagged_version_minor_bump(self):
+        self.repo.commit()
+        self.repo.tag('1.2.3')
+        self.repo.commit('sem-ver: deprecation')
+        version = packaging._get_version_from_git()
+        self.assertThat(version, matchers.StartsWith('1.3.0.dev1.g'))
+
+    def test_untagged_version_major_bump(self):
+        self.repo.commit()
+        self.repo.tag('1.2.3')
+        self.repo.commit('sem-ver: api-break')
+        version = packaging._get_version_from_git()
+        self.assertThat(version, matchers.StartsWith('2.0.0.dev1.g'))
+
     def test_untagged_version_has_dev_version_preversion(self):
         self.repo.commit()
         self.repo.tag('1.2.3')
@@ -244,7 +261,7 @@ class TestVersions(base.BaseTestCase):
         version = packaging._get_version_from_git('1.2.5')
         self.assertThat(version, matchers.StartsWith('1.2.5.dev1.g'))
 
-    def test_preversion_too_low(self):
+    def test_preversion_too_low_simple(self):
         # That is, the target version is either already released or not high
         # enough for the semver requirements given api breaks etc.
         self.repo.commit()
@@ -256,6 +273,42 @@ class TestVersions(base.BaseTestCase):
             ValueError, packaging._get_version_from_git, '1.2.3')
         self.assertThat(err.args[0], matchers.StartsWith('git history'))
 
+    def test_preversion_too_low_semver_headers(self):
+        # That is, the target version is either already released or not high
+        # enough for the semver requirements given api breaks etc.
+        self.repo.commit()
+        self.repo.tag('1.2.3')
+        self.repo.commit('sem-ver: feature')
+        # Note that we can't target 1.2.4, the feature header means we need
+        # to be working on 1.3.0 or above.
+        err = self.assertRaises(
+            ValueError, packaging._get_version_from_git, '1.2.4')
+        self.assertThat(err.args[0], matchers.StartsWith('git history'))
+
+    def test_get_kwargs_corner_cases(self):
+        # No tags:
+        git_dir = self.repo._basedir + '/.git'
+        get_kwargs = lambda tag: packaging._get_increment_kwargs(git_dir, tag)
+
+        def _check_combinations(tag):
+            self.repo.commit()
+            self.assertEqual(dict(), get_kwargs(tag))
+            self.repo.commit('sem-ver: bugfix')
+            self.assertEqual(dict(), get_kwargs(tag))
+            self.repo.commit('sem-ver: feature')
+            self.assertEqual(dict(minor=True), get_kwargs(tag))
+            self.repo.uncommit()
+            self.repo.commit('sem-ver: deprecation')
+            self.assertEqual(dict(minor=True), get_kwargs(tag))
+            self.repo.uncommit()
+            self.repo.commit('sem-ver: api-break')
+            self.assertEqual(dict(major=True), get_kwargs(tag))
+            self.repo.commit('sem-ver: deprecation')
+            self.assertEqual(dict(major=True, minor=True), get_kwargs(tag))
+        _check_combinations('')
+        self.repo.tag('1.2.3')
+        _check_combinations('1.2.3')
+
 
 def load_tests(loader, in_tests, pattern):
     return testscenarios.load_tests_apply_scenarios(loader, in_tests, pattern)