1 files changed, 44 insertions, 0 deletions
diff --git a/lib/declarative_policy/policy_dsl.rb b/lib/declarative_policy/policy_dsl.rb
new file mode 100644
index 00000000000..f11b6e9f730
--- /dev/null
+++ b/lib/declarative_policy/policy_dsl.rb
@@ -0,0 +1,44 @@
+module DeclarativePolicy
+  # The return value of a rule { ... } declaration.
+  # Can call back to register rules with the containing
+  # Policy class (context_class here). See Base.rule
+  #
+  # Note that the #policy method just performs an #instance_eval,
+  # which is useful for multiple #enable or #prevent callse.
+  #
+  # Also provides a #method_missing proxy to the context
+  # class's class methods, so that helper methods can be
+  # defined and used in a #policy { ... } block.
+  class PolicyDsl
+    def initialize(context_class, rule)
+      @context_class = context_class
+      @rule = rule
+    end
+
+    def policy(&b)
+      instance_eval(&b)
+    end
+
+    def enable(*abilities)
+      @context_class.enable_when(abilities, @rule)
+    end
+
+    def prevent(*abilities)
+      @context_class.prevent_when(abilities, @rule)
+    end
+
+    def prevent_all
+      @context_class.prevent_all_when(@rule)
+    end
+
+    def method_missing(m, *a, &b)
+      return super unless @context_class.respond_to?(m)
+
+      @context_class.__send__(m, *a, &b) # rubocop:disable GitlabSecurity/PublicSend
+    end
+
+    def respond_to_missing?(m)
+      @context_class.respond_to?(m) || super
+    end
+  end
+end