[#647] Add git hook script

.prepare-commit-msg.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+
+# This script is an optional git hook and will prepend the issue
+# number to a commit message in the correct format for Github to parse.
+#
+# If you wish to use it, create a shortcut to this file in .git/hooks called
+# 'prepare-commit-msg' e.g. from top folder of your project:
+#   ln -s ./.prepare-commit-msg.py .git/hooks/prepare-commit-msg
+#
+# or, for Windows users:
+#   mklink .git\hooks\prepare-commit-msg .prepare-commit-msg.py
+#
+# If you use a graphical git client, you can configure it so that the issue
+# numbers become clickable in the log view. e.g. for Atlassian SourceTree:
+#   From the 'Repository Settings' menu, click the 'Advanced' tab
+#   In the 'Commit Text Replacements', click the 'Add' button
+#   Select 'Other' as the 'Replacement Type'
+#   Enter '#(\d{1,})' as the 'Regex Pattern'
+#   Enter '<a href="/~https://github.com/Axelrod-Python/Axelrod/issues/$1">#$1</a>' as the 'Replace With'
+#
+# Any issue numbers created by this hook (or entered manually in the correct)
+# format will now be clickable links in the log view.
+
+import sys
+import re
+from subprocess import check_output
+
+# By default, the hook will check to see if the branch name starts with
+# 'issue-' and will then prepend whatever follows in the commit message.
+# e.g. for a branch named 'issue-123', the commit message will start with
+# '[#123]'
+# If you wish to use a diferent prefix on branch names, change it here.
+issue_prefix = 'issue-'
+
+commit_msg_filepath = sys.argv[1]
+branch = check_output(
+    ['git', 'symbolic-ref', '--short', 'HEAD']
+).strip().decode(encoding='UTF-8')
+
+if branch.startswith(issue_prefix):
+    issue_number = re.match('%s(.*)' % issue_prefix, branch).group(1)
+    print("prepare-commit-msg: Prepending [#%s] to commit message" % issue_number)
+
+    with open(commit_msg_filepath, 'r+') as f:
+        content = f.read()
+        f.seek(0, 0)
+        f.write("[#%s] %s" % (issue_number, content))
+else:
+    print("prepare-commit-msg: No changes made to commit message")