Add separate flag for optimistic batching

This commit is still missing the logic to ensure
that the individual MR hashes and those in the
batch MR match

Author: David Szervanszky

marge/app.py

@@ -208,6 +208,11 @@ def regexp(str_regex):
         action='store_true',
         help='Debug logging (includes all HTTP requests etc).\n',
     )
+    parser.add_argument(
+        '--optimistic-batch',
+        action='store_true',
+        help='Experimental optimistic batch (adds trailers to MRs before batching)\n',
+    )
     config = parser.parse_args(args)
 
     if config.use_merge_strategy and config.batch:
@@ -275,6 +280,11 @@ def main(args=None):
         if options.batch:
             logging.warning('Experimental batch mode enabled')
 
+        if options.optimistic_batch:
+            logging.warning(
+                'Experimental optimistic batch mode enabled. This may cause undesirable behaviour with respect to MRs.'
+            )
+
         if options.use_merge_strategy:
             fusion = bot.Fusion.merge
         elif options.rebase_remotely:
@@ -308,6 +318,7 @@ def main(args=None):
                 fusion=fusion,
             ),
             batch=options.batch,
+            optimistic_batch=options.optimistic_batch,
         )
 
         marge_bot = bot.Bot(api=api, config=config)

marge/batch_job.py

@@ -16,8 +16,9 @@ class CannotBatch(Exception):
 class BatchMergeJob(MergeJob):
     BATCH_BRANCH_NAME = 'marge_bot_batch_merge_job'
 
-    def __init__(self, *, api, user, project, repo, options, merge_requests):
+    def __init__(self, *, api, user, project, repo, options, optimistic, merge_requests):
         super().__init__(api=api, user=user, project=project, repo=repo, options=options)
+        self._optimistic = optimistic
         self._merge_requests = merge_requests
 
     def remove_batch_branch(self):
@@ -199,6 +200,10 @@ def execute(self):
                     '%s/%s' % (merge_request_remote, merge_request.source_branch),
                 )
 
+                # Apply the trailers before running the batch MR
+                self.add_trailers(merge_request)
+                self.push_force_to_mr(merge_request, True, source_repo_url, skip_ci=True)
+
                 # Update <source_branch> on latest <batch> branch so it contains previous MRs
                 self.fuse(
                     merge_request.source_branch,

marge/bot.py

@@ -146,7 +146,7 @@ def _process_merge_requests(self, repo_manager, project, merge_requests):
             raise
 
         log.info('Got %s requests to merge;', len(merge_requests))
-        if self._config.batch and len(merge_requests) > 1:
+        if (self._config.batch or self._config.optimistic_batch) and len(merge_requests) > 1:
             log.info('Attempting to merge as many MRs as possible using BatchMergeJob...')
             batch_merge_job = batch_job.BatchMergeJob(
                 api=self._api,
@@ -155,6 +155,7 @@ def _process_merge_requests(self, repo_manager, project, merge_requests):
                 merge_requests=merge_requests,
                 repo=repo,
                 options=self._config.merge_opts,
+                optimistic=self._config.optimistic_batch,
             )
             try:
                 batch_merge_job.execute()
@@ -187,7 +188,7 @@ def _get_single_job(self, project, merge_request, repo, options):
 
 class BotConfig(namedtuple('BotConfig',
                            'user ssh_key_file project_regexp merge_order merge_opts git_timeout ' +
-                           'git_reference_repo branch_regexp source_branch_regexp batch')):
+                           'git_reference_repo branch_regexp source_branch_regexp batch optimistic_batch')):
     pass
 
 

marge/git.py

@@ -131,7 +131,7 @@ def remove_branch(self, branch, *, new_current_branch='master'):
     def checkout_branch(self, branch, start_point=''):
         self.git('checkout', '-B', branch, start_point, '--')
 
-    def push(self, branch, *, source_repo_url=None, force=False):
+    def push(self, branch, *, source_repo_url=None, force=False, skip_ci=False):
         self.git('checkout', branch, '--')
 
         self.git('diff-index', '--quiet', 'HEAD')  # check it is not dirty
@@ -146,7 +146,8 @@ def push(self, branch, *, source_repo_url=None, force=False):
         else:
             source = 'origin'
         force_flag = '--force' if force else ''
-        self.git('push', force_flag, source, '%s:%s' % (branch, branch))
+        skip_flag = ['-o', 'ci.skip'] if skip_ci else []
+        self.git('push', force_flag, *skip_flag, source, '%s:%s' % (branch, branch))
 
     def get_commit_hash(self, rev='HEAD'):
         """Return commit hash for `rev` (default "HEAD")."""

marge/job.py

@@ -336,12 +336,14 @@ def push_force_to_mr(
         merge_request,
         branch_was_modified,
         source_repo_url=None,
+        skip_ci=False,
     ):
         try:
             self._repo.push(
                 merge_request.source_branch,
                 source_repo_url=source_repo_url,
                 force=True,
+                skip_ci=skip_ci,
             )
         except git.GitError:
             def fetch_remote_branch():

pylintrc

@@ -30,6 +30,7 @@ max-line-length=110
 [DESIGN]
 max-args=10
 max-attributes=15
+max-locals=16
 max-public-methods=35
 
 [REPORTS]

tests/git_repo_mock.py

@@ -178,9 +178,11 @@ def merge(self, arg):
             self._local_repo.set_ref(self._branch, new_sha)
 
     def push(self, *args):
-        force_flag, remote_name, refspec = args
+        force_flag, skip_1, skip_2, remote_name, refspec = args
 
         assert force_flag in ('', '--force')
+        assert skip_1 in ('', '-o')
+        assert skip_2 in ('', 'ci.skip')
 
         branch, remote_branch = refspec.split(':')
         remote_url = self._remotes[remote_name]