tests: Use merge reference object instead of raw commit id.

rhodecode/tests/models/test_pullrequest.py

@@ -25,7 +25,8 b' import textwrap'
 import rhodecode
 from rhodecode.lib.utils2 import safe_unicode
 from rhodecode.lib.vcs.backends import get_backend
-from rhodecode.lib.vcs.backends.base import MergeResponse, MergeFailureReason
+from rhodecode.lib.vcs.backends.base import (
+    MergeResponse, MergeFailureReason, Reference)
 from rhodecode.lib.vcs.exceptions import RepositoryError
 from rhodecode.lib.vcs.nodes import FileNode
 from rhodecode.model.comment import ChangesetCommentsModel
@@ -269,10 +270,10 b' class TestPullRequestModel:'
 
     def test_merge(self, pull_request, merge_extras):
         user = UserModel().get_by_username(TEST_USER_ADMIN_LOGIN)
+        merge_ref = Reference(
+            'type', 'name', '6126b7bfcc82ad2d3deaee22af926b082ce54cc6')
         self.merge_mock.return_value = MergeResponse(
-            True, True,
-            '6126b7bfcc82ad2d3deaee22af926b082ce54cc6',
-            MergeFailureReason.NONE)
+            True, True, merge_ref, MergeFailureReason.NONE)
 
         merge_extras['repository'] = pull_request.target_repo.repo_name
         PullRequestModel().merge(
@@ -308,10 +309,10 b' class TestPullRequestModel:'
 
     def test_merge_failed(self, pull_request, merge_extras):
         user = UserModel().get_by_username(TEST_USER_ADMIN_LOGIN)
+        merge_ref = Reference(
+            'type', 'name', '6126b7bfcc82ad2d3deaee22af926b082ce54cc6')
         self.merge_mock.return_value = MergeResponse(
-            False, False,
-            '6126b7bfcc82ad2d3deaee22af926b082ce54cc6',
-            MergeFailureReason.MERGE_FAILED)
+            False, False, merge_ref, MergeFailureReason.MERGE_FAILED)
 
         merge_extras['repository'] = pull_request.target_repo.repo_name
         PullRequestModel().merge(