Refactor code for protecting default branches

This refactors some of the logic used for protecting default branches,
in particular Project#after_create_default_branch. The logic for this
method is moved into a separate service class. Ideally we'd get rid of
Project#after_create_default_branch entirely, but unfortunately
Project#after_import depends on it. This means it has to stick around
until we also refactor Project#after_import.

For branch protection levels we introduce
Gitlab::Access::BranchProtection, which provides a small wrapper around
Integer based branch protection levels. Using this class removes the
need for having to constantly refer to Gitlab::Access::PROTECTION_*
constants.

1 files changed, 42 insertions, 0 deletions

diff --git a/lib/gitlab/access/branch_protection.rb b/lib/gitlab/access/branch_protection.rb
new file mode 100644
index 00000000000..f039e5c011f
--- /dev/null
+++ b/lib/gitlab/access/branch_protection.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Access
+    # A wrapper around Integer based branch protection levels.
+    #
+    # This wrapper can be used to work with branch protection levels without
+    # having to directly refer to the constants. For example, instead of this:
+    #
+    #     if access_level == Gitlab::Access::PROTECTION_DEV_CAN_PUSH
+    #       ...
+    #     end
+    #
+    # You can write this instead:
+    #
+    #     protection = BranchProtection.new(access_level)
+    #
+    #     if protection.developer_can_push?
+    #       ...
+    #     end
+    class BranchProtection
+      attr_reader :level
+
+      # @param [Integer] level The branch protection level as an Integer.
+      def initialize(level)
+        @level = level
+      end
+
+      def any?
+        level != PROTECTION_NONE
+      end
+
+      def developer_can_push?
+        level == PROTECTION_DEV_CAN_PUSH
+      end
+
+      def developer_can_merge?
+        level == PROTECTION_DEV_CAN_MERGE
+      end
+    end
+  end
+end