Allow version detection from conventional commits

CHANGELOG.md

@@ -12,6 +12,7 @@
 - Hooks are now passed the VERSION as an environment variable.
 - Hooks can now be placed in files inside `.maintain/hooks` such as
   `.maintain/hooks/pre_release`.
+- Added a Conventional Commits releaser.
 
 
 ## 0.2.0 (2016-05-10)

docs/index.rst

@@ -67,6 +67,7 @@ Maintain supports the following releasers:
    release/npm
    release/cocoapods
    release/c
+   release/conventional-commits
 
 Custom Hooks
 ~~~~~~~~~~~~

docs/release/conventional-commits.md

@@ -0,0 +1,17 @@
+# Conventional Commits Releaser
+
+Conventional Commit releaser allows the detection of the next semantic version
+based upon the [conventional commit](http://conventionalcommits.org) messages.
+
+## Detect
+
+Detection is disabled. The Conventional Commits release needs to be explicitly
+enabled.
+
+## Bump
+
+There is no bump steps for the Conventional Commits releaser.
+
+## Release
+
+There is no release steps for the Conventional Commits releaser.

maintain/release/conventional_commits.py

@@ -0,0 +1,59 @@
+import os
+import re
+
+from semantic_version import Version
+from git import Repo, TagReference
+
+from maintain.release.base import Releaser
+
+
+class ConvetionalCommitsReleaser(Releaser):
+    name = 'Conventional Commits'
+
+    @classmethod
+    def detect(cls):
+        return os.path.exists('.git')
+
+    def __init__(self):
+        self.repo = Repo()
+
+    def determine_current_version(self):
+        tags = TagReference.list_items(self.repo)
+        versions = [Version(tag.tag.tag) for tag in tags]
+        return next(reversed(sorted(versions)))
+
+    def determine_next_version(self):
+        current_version = self.determine_current_version()
+
+        if current_version.prerelease or current_version.build:
+            return None
+
+        breaking = 0
+        feats = 0
+        fixes = 0
+
+        pattern = re.compile(r'^((\w+)(?:\(([^\)\s]+)\))?: (.+))+', re.MULTILINE)
+
+        commits = self.repo.iter_commits('master...{}'.format(current_version))
+        for commit in commits:
+            if 'BREAKING CHANGE:' in commit.message:
+                breaking += 1
+
+            result = pattern.search(commit.message.strip())
+            if result:
+                typ = result.group(2)
+                if typ == 'feat':
+                    feats += 1
+                elif typ == 'fix':
+                    fixes += 1
+                else:
+                    raise Exception('Commit "{}" uses unsupported type {}'.format(commit, typ))
+            else:
+                raise Exception('Commit "{}" does not follow conventional commit'.format(commit))
+
+        if breaking > 0:
+            return current_version.next_major()
+        elif feats > 0:
+            return current_version.next_minor()
+        elif fixes > 0:
+            return current_version.next_patch()

tests/release/test_conventional_commits.py

@@ -0,0 +1,122 @@
+import unittest
+
+from maintain.release.conventional_commits import ConvetionalCommitsReleaser
+from ..utils import git_repo, touch
+
+
+class ConventionalCommitsReleaserTestCase(unittest.TestCase):
+    # Detection
+
+    def test_detects_git_repo(self):
+        with git_repo():
+            self.assertTrue(ConvetionalCommitsReleaser.detect())
+
+    # Detect Current Version
+
+    def test_detect_current_version(self):
+        with git_repo() as repo:
+            version = '1.0.0'
+            touch('README.md')
+            repo.index.add(['README.md'])
+            repo.index.commit('Initial commit')
+            repo.create_tag(version, message=version)
+
+            version = '1.1.0'
+            touch('TEST.md')
+            repo.index.add(['TEST.md'])
+            repo.index.commit('Second Commit')
+            repo.create_tag(version, message=version)
+
+            releaser = ConvetionalCommitsReleaser()
+            current_version = releaser.determine_current_version()
+            self.assertEqual(str(current_version), '1.1.0')
+
+    # Detect Next Version
+
+    def test_detect_next_version_patch(self):
+        with git_repo() as repo:
+            version = '1.0.0'
+            touch('README.md')
+            repo.index.add(['README.md'])
+            repo.index.commit('Initial commit')
+            repo.create_tag(version, message=version)
+
+            touch('TEST.md')
+            repo.index.add(['TEST.md'])
+            repo.index.commit('fix: some bug')
+
+            releaser = ConvetionalCommitsReleaser()
+            current_version = releaser.determine_next_version()
+            self.assertEqual(str(current_version), '1.0.1')
+
+    def test_detect_next_version_minor(self):
+        with git_repo() as repo:
+            version = '1.0.0'
+            touch('README.md')
+            repo.index.add(['README.md'])
+            repo.index.commit('Initial commit')
+            repo.create_tag(version, message=version)
+
+            touch('TEST.md')
+            repo.index.add(['TEST.md'])
+            repo.index.commit('feat: some bug')
+
+            releaser = ConvetionalCommitsReleaser()
+            current_version = releaser.determine_next_version()
+            self.assertEqual(str(current_version), '1.1.0')
+
+    def test_detect_next_version_major(self):
+        with git_repo() as repo:
+            version = '1.0.0'
+            touch('README.md')
+            repo.index.add(['README.md'])
+            repo.index.commit('Initial commit')
+            repo.create_tag(version, message=version)
+
+            touch('TEST.md')
+            repo.index.add(['TEST.md'])
+            repo.index.commit('feat: some bug\n\nBREAKING CHANGE: This removes some flag')
+
+            releaser = ConvetionalCommitsReleaser()
+            current_version = releaser.determine_next_version()
+            self.assertEqual(str(current_version), '2.0.0')
+
+    def test_detect_next_version_various_commits(self):
+        with git_repo() as repo:
+            version = '1.0.0'
+            touch('README.md')
+            repo.index.add(['README.md'])
+            repo.index.commit('Initial commit')
+            repo.create_tag(version, message=version)
+
+            touch('TEST.md')
+            repo.index.add(['TEST.md'])
+            repo.index.commit('fix: that awful bug')
+
+            touch('TEST1.md')
+            repo.index.add(['TEST1.md'])
+            repo.index.commit('feat: awesome feature')
+
+            touch('TEST2.md')
+            repo.index.add(['TEST2.md'])
+            repo.index.commit('fix: some other bug')
+
+            releaser = ConvetionalCommitsReleaser()
+            current_version = releaser.determine_next_version()
+            self.assertEqual(str(current_version), '1.1.0')
+
+    def test_detect_next_version_with_scope(self):
+        with git_repo() as repo:
+            version = '1.0.0'
+            touch('README.md')
+            repo.index.add(['README.md'])
+            repo.index.commit('Initial commit')
+            repo.create_tag(version, message=version)
+
+            touch('TEST.md')
+            repo.index.add(['TEST.md'])
+            repo.index.commit('feat(scope): that awful bug')
+
+            releaser = ConvetionalCommitsReleaser()
+            current_version = releaser.determine_next_version()
+            self.assertEqual(str(current_version), '1.1.0')