Make sure commit linter checks all commits

In a previous commit (0cba95a) test_commit_message.py was introduced
under the assumption that circleci would run against all commits. We
soon realized that this was not the case and in fact we were only
checking the HEAD commit.

This commit introduces the following changes:

  1) Creates a new direrctory called 'ci'
  2) Moves test_commit_message.py from 'tests' to 'ci'
  3) Made moderate edits to test_commit_message.py in order to create a
     separate commit message linting function. Also updated the error
     messages to specify the offending commit.

Resolves tern-tools#309

Signed-off-by: Rose Judge <[email protected]>

.circleci/config.yml

@@ -41,7 +41,7 @@ jobs:
     steps:
       - setup
       - run: pip install -r dev-requirements.txt
-      - run: python tests/test_commit_message.py
+      - run: python ci/test_commit_message.py
   # full functional test for photonOS
   funcphoton:
     executor: ubuntu1604

ci/test_commit_message.py

@@ -0,0 +1,60 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2019 VMware, Inc. All Rights Reserved.
+# SPDX-License-Identifier: BSD-2-Clause
+
+from git import Repo
+import os
+import re
+import sys
+
+# This script is written to be used with circleci and
+# is not meant to be run locally
+
+def lint_commit(commit_id):
+    """Given a commit ID, determine if the 
+    commit message complies with the tern guidelines. If
+    it does not comply, output the offending commit and
+    specify the reason for failure."""
+
+    r = Repo(os.getcwd())
+    check = True
+    message = r.commit(commit_id).message
+    sha_short = r.git.rev_parse(commit_id, short=7)
+
+    # Check 1: Subject, body and DCO exist
+    # Note that git does not allow for empty subjects
+    if len(re.split('\n\n|\r', message)) <= 2:
+        print("Commit {} does not have a body.".format(sha_short))
+        check = False
+
+    # Check 2: Subject length is less than about 50
+    if len(re.split('\n\n', message)[0]) > 54:
+        print("The subject of commit {} should be 50 characters or less.".format(sha_short))
+        check = False
+
+    #Check 3: Each line of the body is less than 72
+    body = re.split('\n\n|\r', message, 1)[1]
+    for i in range(len(body)):
+        if len(body[i]) > 72:
+            print("Line {0} of commit {1} exceeds 72 characters.".format(i+1, sha_short))
+            check = False
+
+    if not check:
+        sys.exit(1)
+
+if __name__ == '__main__':
+    # Get the list of commits and loop through them,
+    # inputting each one into the linting function
+
+    # We are in the 'tern' directory
+    repo = Repo(os.getcwd())
+    repo.git.remote('add', 'upstream', '[email protected]:vmware/tern.git')
+    repo.git.fetch('upstream')
+    # Will give list of commit IDs differentiating HEAD and master
+    commits = repo.git.rev_list('HEAD', '^upstream/master').split('\n')
+
+    for commit_id in commits:
+        lint_commit(commit_id)
+
+