Add git pull --rebase {base-branch} call at GitHelper::squashCommits()

Author: phansys

src/Helper/GitHelper.php

@@ -650,6 +650,16 @@ public function squashCommits($base, $branchName, $ignoreMultipleAuthors = false
                 '-author' => $author,
             ]
         );
+
+        try {
+            // Ensure squashed commits don't introduce regressions at base branch
+            $this->processHelper->runCommand(['git', 'pull', '--rebase', $base]);
+        } catch (\Exception $e) {
+            // Error, abort the rebase process
+            $this->processHelper->runCommand(['git', 'rebase', '--abort'], true);
+
+            throw new \RuntimeException(sprintf('Git rebase failed while trying to synchronize history against "%s".', $base), 0, $e);
+        }
     }
 
     public function syncWithRemote($remote, $branchName = null)