Constants for Protected Branches feature

app/assets/javascripts/protected_branches/ee/constants.js

+export const ACCESS_LEVELS = {
+  MERGE: 'merge_access_levels',
+  PUSH: 'push_access_levels',
+};
+
+export const LEVEL_TYPES = {
+  ROLE: 'role',
+  USER: 'user',
+  GROUP: 'group',
+};
+
+export const ACCESS_LEVEL_NONE = 0;