Add `source_branch` option for various git operations

If `source_branch` option is passed, and target branch cannot be found,
`Repository#update_branch_with_hooks` would try to create a new branch
from `source_branch`.

This way, we could make changes in the new branch while only firing
the hooks once for the changes. Previously, we can only create a new
branch first then make changes to the new branch, firing hooks twice.
This behaviour is bad for CI.

Fixes #7237

1 files changed, 11 insertions, 11 deletions

diff --git a/app/services/create_branch_service.rb b/app/services/create_branch_service.rb
index 757fc35a78f..f4270a09928 100644
--- a/app/services/create_branch_service.rb
+++ b/app/services/create_branch_service.rb
@@ -2,18 +2,9 @@ require_relative 'base_service'
 
 class CreateBranchService < BaseService
   def execute(branch_name, ref, source_project: @project)
-    valid_branch = Gitlab::GitRefValidator.validate(branch_name)
+    failure = validate_new_branch(branch_name)
 
-    unless valid_branch
-      return error('Branch name is invalid')
-    end
-
-    repository = project.repository
-    existing_branch = repository.find_branch(branch_name)
-
-    if existing_branch
-      return error('Branch already exists')
-    end
+    return failure if failure
 
     new_branch = if source_project != @project
                    repository.fetch_ref(
@@ -41,4 +32,13 @@ class CreateBranchService < BaseService
   def success(branch)
     super().merge(branch: branch)
   end
+
+  private
+
+  def validate_new_branch(branch_name)
+    result = ValidateNewBranchService.new(project, current_user).
+      execute(branch_name)
+
+    error(result[:message]) if result[:status] == :error
+  end
 end