Add predicate methods for CurrentAttributes

Add support for predicate with no arguments

activesupport/lib/active_support/current_attributes.rb

@@ -112,6 +112,12 @@ def attribute(*names)
                 "attributes[:#{name}] = value" <<
                 "end"
             end
+            owner.define_cached_method("#{name}?", namespace: :current_attributes) do |batch|
+              batch <<
+              "def #{name}?(value = nil)" <<
+              "value ? attributes[:#{name}] == value : attributes[:#{name}].present?" <<
+              "end"
+            end
           end
         end
 

activesupport/test/current_attributes_test.rb

@@ -176,6 +176,43 @@ def after_teardown
     assert_equal true, Current.respond_to?("respond_to_test")
   end
 
+  test "+attribute+? returns true if value set and no argument given" do
+    person = Person.new(42, "David", "Central Time (US & Canada)")
+    Current.person = person
+    assert Current.person?
+  end
+
+  test "+attribute+? returns false if value nil and no argument given" do
+    Current.world = nil
+    refute Current.world?
+  end
+
+  test "+attribute+? returns false if value blank and no argument" do
+    Current.world = ""
+    refute Current.world?
+  end
+
+  test "+attribute+? returns true if value matches argument" do
+    person = Person.new(42, "David", "Central Time (US & Canada)")
+    Current.person = person
+    assert Current.person?(person)
+  end
+
+  test "+attribute+? returns false if value doesn't match argument" do
+    person_a = Person.new(42, "David", "Central Time (US & Canada)")
+    person_b = Person.new(43, "Other Person", "Central Time (US & Canada)")
+    Current.person = person_a
+    refute Current.person?(person_b)
+  end
+
+  test "+attribute+? returns true in block Current.set" do
+    person = Person.new(42, "David", "Central Time (US & Canada)")
+    Current.set(person: person) do
+      assert Current.person?(person)
+    end
+    refute Current.person?(person)
+  end
+
   test "CurrentAttributes use fiber-local variables" do
     previous_level = ActiveSupport::IsolatedExecutionState.isolation_level
     ActiveSupport::IsolatedExecutionState.isolation_level = :fiber