Don't allow re-assigning Query#validate after validation

lib/graphql/query.rb

@@ -34,7 +34,16 @@ def initialize(name)
     attr_accessor :operation_name
 
     # @return [Boolean] if false, static validation is skipped (execution behavior for invalid queries is undefined)
-    attr_accessor :validate
+    attr_reader :validate
+
+    # @param new_validate [Boolean] if false, static validation is skipped. This can't be reasssigned after validation.
+    def validate=(new_validate)
+      if defined?(@validation_pipeline) && @validation_pipeline && @validation_pipeline.has_validated?
+        raise ArgumentError, "Can't reassign Query#validate= after validation has run, remove this assignment."
+      else
+        @validate = new_validate
+      end
+    end
 
     attr_writer :query_string
 

lib/graphql/query/validation_pipeline.rb

@@ -45,6 +45,10 @@ def analyzers
         @query_analyzers
       end
 
+      def has_validated?
+        @has_validated == true
+      end
+
       private
 
       # If the pipeline wasn't run yet, run it.

spec/graphql/query_spec.rb

@@ -720,6 +720,24 @@ def self.parse_error(err, ctx)
       assert_equal true, query.valid?
       assert_equal 0, query.static_errors.length
     end
+
+    it "can't be reassigned after validating" do
+      query = GraphQL::Query.new(schema, "{ nonExistingField }")
+      assert query.fingerprint
+      query.validate = false
+      assert_equal true, query.valid?
+      assert_equal 0, query.static_errors.length
+      err = assert_raises ArgumentError do
+        query.validate = true
+      end
+
+      err2 = assert_raises ArgumentError do
+        query.validate = false
+      end
+      expected_message = "Can't reassign Query#validate= after validation has run, remove this assignment."
+      assert_equal expected_message, err.message
+      assert_equal expected_message, err2.message
+    end
   end
 
   describe "validating with optional arguments and variables: nil" do