Add commit support.

Author: waylan

README.md

@@ -113,7 +113,25 @@ The following table provides various examples (with the defaults set as
 
 ### Commits
 
-This feature is *not yet implemented*.
+Link directly to a GitHub Commit. Note that no verification is made that an
+actual commit exists.
+
+Commit links consist of a complete 40 character SHA hash and may optionally be
+prefaced by `{user}@` or `{user/project}@`. `{user}` and `{project}` will use
+the defaults defined in the configuration options if not provided. To avoid a 40
+character hash from being linked, wrap it in a code span.
+
+All issue links are assigned the `gh-commit` class.
+
+The following table provides various examples (with the defaults set as
+`user='user', project='project'`):
+
+| shorthand                                          | href                                                                              | rendered result                                                                                                                                                     |
+| -------------------------------------------------- | --------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `72df691791fb36f00cf5363fefe757c8d3042656`         | `https://github.com/user/project/commit/72df691791fb36f00cf5363fefe757c8d3042656` | [72df691](https://github.com/user/project/commit/72df691791fb36f00cf5363fefe757c8d3042656 "GitHub Commit: user/project@72df691791fb36f00cf5363fefe757c8d3042656")   |
+| `foo@72df691791fb36f00cf5363fefe757c8d3042656`     | `https://github.com/foo/project/commit/72df691791fb36f00cf5363fefe757c8d3042656`  | [foo@72df691](https://github.com/foo/project/commit/72df691791fb36f00cf5363fefe757c8d3042656 "GitHub Commit: foo/project@72df691791fb36f00cf5363fefe757c8d3042656") |
+| `foo/bar@72df691791fb36f00cf5363fefe757c8d3042656` | `https://github.com/foo/bar/commit/72df691791fb36f00cf5363fefe757c8d3042656`      | [foo/bar@72df691](https://github.com/foo/bar/commit/72df691791fb36f00cf5363fefe757c8d3042656 "GitHub Commit: foo/bar@72df691791fb36f00cf5363fefe757c8d3042656")     |
+| `` `72df691791fb36f00cf5363fefe757c8d3042656` ``   |                                                                                   | `72df691791fb36f00cf5363fefe757c8d3042656`                                                                                                                          |
 
 ## License
 

mdx_gh_links.py

@@ -37,7 +37,7 @@
 
 URL_BASE = 'https://github.com'
 RE_PARTS = dict(
-    USER=r'[-_\w]+',
+    USER=r'[-_\w]{1,39}\b',
     PROJECT=r'[-_.\w]+\b'
 )
 
@@ -86,6 +86,27 @@ def handleMatch(self, m):
         return _build_link(label, title, href, 'gh-link gh-issue')
 
 
+class CommitPattern(Pattern):
+    def __init__(self, config, md):
+        COMMIT_RE = r'((?:({USER})(?:\/({PROJECT}))?@|\b)([a-f0-9]{{40}})\b)'.format(**RE_PARTS)
+        super(CommitPattern, self).__init__(COMMIT_RE, md)
+        self.config = config
+
+    def handleMatch(self, m):
+        user = m.group(3)
+        project = m.group(4) or self.config['project']
+        commit = m.group(5)
+        short = commit[:7]
+        if user:
+            label = '{0}@{1}'.format(m.group(2).split('@')[0], short)
+        else:
+            label = short
+            user = self.config['user']
+        title = 'GitHub Commit: {0}/{1}@{2}'.format(user, project, commit)
+        href = '{0}/{1}/{2}/commit/{3}'.format(URL_BASE, user, project, commit)
+        return _build_link(label, title, href, 'gh-link gh-commit')
+
+
 class GithubLinks(Extension):
     def __init__(self, *args, **kwargs):
         self.config = {
@@ -98,6 +119,7 @@ def extendMarkdown(self, md, md_globals):
         md.ESCAPED_CHARS.append('@')
         md.inlinePatterns['issue'] = IssuePattern(self.getConfigs(), md)
         md.inlinePatterns['mention'] = MentionPattern(self.getConfigs(), md)
+        md.inlinePatterns['commit'] = CommitPattern(self.getConfigs(), md)
 
 
 def makeExtension(*args, **kwargs):

test_gh_links.py

@@ -147,6 +147,38 @@ def test_escape_mention_project(self):
             '<p>User @foo/bar.</p>',
         )
 
+    # Commit Tests
+    def test_commit(self):
+        self.assertMarkdownRenders(
+            'Commit 83fb46b3b7ab8ad4316681fc4637c521da265f1d.',
+            '<p>Commit <a class="gh-link gh-commit" '
+            'href="https://github.com/Python-Markdown/github-links/commit/83fb46b3b7ab8ad4316681fc4637c521da265f1d" '
+            'title="GitHub Commit: Python-Markdown/github-links@83fb46b3b7ab8ad4316681fc4637c521da265f1d"'
+            '>83fb46b</a>.</p>',
+        )
+
+    def test_commit_user(self):
+        self.assertMarkdownRenders(
+            'Commit foo@15abb8b3b02df0e380e9b4c71f3bd206c9751a93.',
+            '<p>Commit <a class="gh-link gh-commit" '
+            'href="https://github.com/foo/github-links/commit/15abb8b3b02df0e380e9b4c71f3bd206c9751a93" '
+            'title="GitHub Commit: foo/github-links@15abb8b3b02df0e380e9b4c71f3bd206c9751a93"''>foo@15abb8b</a>.</p>',
+        )
+
+    def test_commit_user_project(self):
+        self.assertMarkdownRenders(
+            'Commit foo/bar@a75944f869d728ca9bc5472daf3f249b6c341308.',
+            '<p>Commit <a class="gh-link gh-commit" '
+            'href="https://github.com/foo/bar/commit/a75944f869d728ca9bc5472daf3f249b6c341308" '
+            'title="GitHub Commit: foo/bar@a75944f869d728ca9bc5472daf3f249b6c341308">foo/bar@a75944f</a>.</p>',
+        )
+
+    def test_escape_commit(self):
+        self.assertMarkdownRenders(
+            'Commit `83fb46b3b7ab8ad4316681fc4637c521da265f1d`.',
+            '<p>Commit <code>83fb46b3b7ab8ad4316681fc4637c521da265f1d</code>.</p>',
+        )
+
 
 if __name__ == '__main__':
     unittest.main()