1 files changed, 56 insertions, 0 deletions
diff --git a/app/graphql/mutations/branch_rules/create.rb b/app/graphql/mutations/branch_rules/create.rb
new file mode 100644
index 00000000000..c478d981c33
--- /dev/null
+++ b/app/graphql/mutations/branch_rules/create.rb
@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+module Mutations
+  module BranchRules
+    class Create < BaseMutation
+      graphql_name 'BranchRuleCreate'
+
+      argument :project_path, GraphQL::Types::ID,
+        required: true,
+        description: 'Full path to the project that the branch is associated with.'
+
+      argument :name, GraphQL::Types::String,
+        required: true,
+        description: 'Branch name, with wildcards, for the branch rules.'
+
+      field :branch_rule,
+        Types::Projects::BranchRuleType,
+        null: true,
+        description: 'Branch rule after mutation.'
+
+      def resolve(project_path:, name:)
+        project = Project.find_by_full_path(project_path)
+
+        service_params = protected_branch_params(name)
+        protected_branch = ::ProtectedBranches::CreateService.new(project, current_user, service_params).execute
+
+        if protected_branch.persisted?
+          {
+            branch_rule: ::Projects::BranchRule.new(project, protected_branch),
+            errors: []
+          }
+        else
+          { errors: errors_on_object(protected_branch) }
+        end
+      rescue Gitlab::Access::AccessDeniedError
+        raise_resource_not_available_error!
+      end
+
+      def protected_branch_params(name)
+        {
+          name: name,
+          push_access_levels_attributes: access_level_attributes(:push),
+          merge_access_levels_attributes: access_level_attributes(:merge)
+        }
+      end
+
+      def access_level_attributes(type)
+        ::ProtectedRefs::AccessLevelParams.new(
+          type,
+          {},
+          with_defaults: true
+        ).access_levels
+      end
+    end
+  end
+end