Add Mongoid::RawValue wrapper

Author: johnnyshields

docs/release-notes/mongoid-8.1.txt

@@ -118,6 +118,24 @@ See the section on :ref:`Localize :present Field Option <present-fields>` for
 more details on how these are used.
 
 
+Support for Passing Raw Values into Queries
+-------------------------------------------
+
+When performing queries, it is now possible skip Mongoid's type coercion logic
+using the ``Mongoid::RawValue`` wrapper class. This can be useful when legacy
+data in the database is of a different type than the field definition.
+
+.. code-block:: ruby
+
+   class Person
+     include Mongoid::Document
+     field :age, type: Integer
+   end
+
+   # Query for the string "42", not the integer 42
+   Person.where(age: Mongoid::RawValue("42"))
+
+
 Added ``:to`` and ``:from`` options to ``attribute_changed?``
 -------------------------------------------------------------
 

lib/mongoid/criteria/queryable/selector.rb

@@ -150,16 +150,20 @@ def evolve_multi(specs)
         #
         # @return [ Object ] The serialized object.
         def evolve(serializer, value)
-          case value
-          when Hash
-            evolve_hash(serializer, value)
-          when Array
-            evolve_array(serializer, value)
-          when Range
-            value.__evolve_range__(serializer: serializer)
-          else
-            (serializer || value.class).evolve(value)
-          end
+          _value = case value
+                   when Hash
+                     evolve_hash(serializer, value)
+                   when Array
+                     evolve_array(serializer, value)
+                   when Range
+                     value.__evolve_range__(serializer: serializer)
+                   when Mongoid::RawValue
+                     value
+                   else
+                     (serializer || value.class).evolve(value)
+                   end
+          _value = _value.raw_value if _value.is_a?(Mongoid::RawValue)
+          _value
         end
 
         # Evolve a single key selection with array values.

lib/mongoid/extensions.rb

@@ -48,6 +48,7 @@ def transform_keys
 require "mongoid/extensions/object"
 require "mongoid/extensions/object_id"
 require "mongoid/extensions/range"
+require "mongoid/extensions/raw_value"
 require "mongoid/extensions/regexp"
 require "mongoid/extensions/set"
 require "mongoid/extensions/string"

lib/mongoid/extensions/raw_value.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# Wrapper class used when a value cannot be casted in evolve method.
+module Mongoid
+  def RawValue(*args)
+    RawValue.new(*args)
+  end
+
+  class RawValue
+
+    attr_reader :raw_value
+
+    def initialize(raw_value)
+      @raw_value = raw_value
+    end
+
+    # Delegate all missing methods to the raw value.
+    #
+    # @param [ String, Symbol ] method_name The name of the method.
+    # @param [ Array ] args The arguments passed to the method.
+    ruby2_keywords def method_missing(method_name, *args, &block)
+      raw_value.send(method_name, *args, &block)
+    end
+
+    # Delegate all missing methods to the raw value.
+    #
+    # @param [ String, Symbol ] method_name The name of the method.
+    # @param [ true | false ] include_private Whether to check private methods.
+    def respond_to_missing?(method_name, include_private = false)
+      raw_value.respond_to?(method_name, include_private)
+    end
+  end
+end