Proof of concept on "strict" field option

Author: johnnyshields

docs/reference/fields.txt

@@ -827,6 +827,34 @@ Mongoid also defines the ``id`` field aliased to ``_id``. The ``id``
 alias can :ref:`be removed <unalias-id>` if desired (such as to integrate
 with systems that use the ``id`` field to store value different from ``_id``.
 
+.. _uncastable-values:
+
+Assigning Uncastable Values
+---------------------------
+
+In Mongoid 8, Mongoid has standardized the treatment of the assignment of
+"uncastable" values. A value is considered "uncastable" when it cannot be
+coerced to the type of the field. For example:
+
+.. code::
+
+  class User
+    include Mongoid::Document
+
+    field :name, type: Integer
+  end
+
+  User.new(name: [ "hello" ])
+
+Assigning an array to a field of type Integer doesn't work since an array can't
+be coerced to an Integer. The assignment of uncastable values to a field will
+cause a ``nil`` to be written:
+
+.. code::
+
+  User.new(name: [ "hello" ])
+  # => #<User _id: 62b222d43282a47bf73e3264, name: nil>
+
 
 .. _customizing-field-behavior:
 
@@ -978,6 +1006,12 @@ setter methods for fields of your custom type.
    venue = Venue.new(location: point) # This uses the Point#mongoize instance method.
    venue = Venue.new(location: [ 12, 24 ]) # This uses the Point.mongoize class method.
 
+.. note::
+
+  The ``mongoize`` method should return ``nil`` on values that are uncastable to
+  your custom type. See the secion on :ref:`Uncastable Values <uncastable-values>`
+  for more details.
+
 The class method ``demongoize`` does the inverse of ``mongoize``. It takes the raw object
 from the MongoDB Ruby driver and converts it to an instance of your custom type.
 In this case, the database driver returns an ``Array`` and we instantiate a ``Point`` from it.

docs/release-notes/mongoid-8.0.txt

@@ -57,6 +57,39 @@ changed in Mongoid 8.0:
 Please refer to :ref:`configuration option <configuration-options>` for
 the description and effects of each of these options.
 
+Storing Uncastable Value
+------------------------
+
+In Mongoid 8, Mongoid standardizes the storing of "uncastable values." On
+attempting to write an uncastable value, a ``nil`` is written instead. See the
+secion on :ref:`Uncastable Values <uncastable-values>` for more details.
+
+Some ``mongoize`` methods were also changed to perform consistently with rails
+and the other mongoize methods. The following is a table of the changes in
+functionality:
+
++--------------+------------------------+------------------------+-------------------+
+| Field Type   | Situation              | Previous Functionality | New Functionality |
++==============+========================+========================+===================+
+| Boolean      | When a non-boolean     | return ``false``       | return ``nil``    |
+|              | string is assigned:    |                        |                   |
+|              | "bogus value"          |                        |                   |
++--------------+------------------------+------------------------+-------------------+
+| Symbol       | When a value that does | return ``nil``         | return ``nil``    |
+|              | not respond to         |                        |                   |
+|              | ``to_sym`` is          |                        |                   |
+|              | assigned: ``[]``       |                        |                   |
++--------------+------------------------+------------------------+-------------------+
+| Array/Set    | When a value that is   | raise ``InvalidValue`` | return ``nil``    |
+|              | not an array or set is | error                  |                   |
+|              | assigned, and does NOT |                        |                   |
+|              | respond to ``to_a``: 1 |                        |                   |
++--------------+------------------------+------------------------+-------------------+
+| All Other    | When an uncastable     | undefined behavior,    | return ``nil``    |
+| Types        | value is assigned      | occasionally raises    |                   |
+|              |                        | ``NoMethodError``      |                   |
++--------------+------------------------+------------------------+-------------------+
+
 
 Order of Callback Invocation
 ----------------------------

lib/config/locales/en.yml

@@ -372,10 +372,6 @@ en:
             from the child side which association to go in."
           resolution: "Set the values from the parent, or redefine the association
             with only a single definition in the parent."
-        invalid_value:
-          message: "Value of type %{value_class} cannot be written to a field of type %{field_class}"
-          summary: "Tried to set a value of type %{value_class} to a field of type %{field_class}"
-          resolution: "Verify if the value to be set correspond to field definition"
         mixed_relations:
           message: "Referencing a(n) %{embedded} document from the %{root}
             document via a non-embedded association is not allowed since the

lib/mongoid/criteria/queryable/extensions/array.rb

@@ -133,10 +133,11 @@ module ClassMethods
             #
             # @return [ Object ] The evolved object.
             def evolve(object)
-              if object.is_a?(::Array)
+              case object
+              when ::Array, ::Set
                 object.map { |obj| obj.class.evolve(obj) }
               else
-                object
+                Mongoid::UncastableValue(object, 'Array')
               end
             end
           end

lib/mongoid/criteria/queryable/extensions/boolean.rb

@@ -20,7 +20,8 @@ module ClassMethods
             # @return [ true, false ] The boolean value.
             def evolve(object)
               __evolve__(object) do |obj|
-                obj.to_s =~ (/\A(true|t|yes|y|on|1|1.0)\z/i) ? true : false
+                res = mongoize(object)
+                res.nil? ? object : res
               end
             end
           end

lib/mongoid/errors.rb

@@ -37,7 +37,6 @@
 require "mongoid/errors/invalid_storage_options"
 require "mongoid/errors/invalid_storage_parent"
 require "mongoid/errors/invalid_time"
-require "mongoid/errors/invalid_value"
 require "mongoid/errors/inverse_not_found"
 require "mongoid/errors/mixed_relations"
 require "mongoid/errors/mixed_client_configuration"

lib/mongoid/extensions/array.rb

@@ -87,7 +87,7 @@ def multi_arged?
       # @example Mongoize the object.
       #   object.mongoize
       #
-      # @return [ Array ] The object.
+      # @return [ Array | nil ] The object or nil.
       def mongoize
         ::Array.mongoize(self)
       end
@@ -144,12 +144,14 @@ def __mongoize_fk__(association, object)
         #
         # @param [ Object ] object The object to mongoize.
         #
-        # @return [ Array ] The object mongoized.
+        # @return [ Array | nil ] The object mongoized or nil.
         def mongoize(object)
-          if object.is_a?(::Array)
+          return if object.nil?
+          case object
+          when ::Array, ::Set
             evolve(object).collect{ |obj| obj.class.mongoize(obj) }
           else
-            evolve(object)
+            Mongoid::UncastableValue(object, 'Array')
           end
         end
 

lib/mongoid/extensions/big_decimal.rb

@@ -20,13 +20,9 @@ def __to_inc__
       # @example Mongoize the object.
       #   object.mongoize
       #
-      # @return [ Object ] The object.
+      # @return [ String | BSON::Decimal128 | nil ] The object or nil.
       def mongoize
-        if Mongoid.map_big_decimal_to_decimal128
-          BSON::Decimal128.new(self)
-        else
-          to_s
-        end
+        ::BigDecimal.mongoize(self)
       end
 
       # Is the BigDecimal a number?
@@ -67,21 +63,25 @@ def demongoize(object)
         # @param [ Object ] object The object to Mongoize
         #
         # @return [ String | BSON::Decimal128 | nil ] A String or Decimal128
-        #   representing the object or nil.
+        #   representing the object or nil. String if Mongoid.map_big_decimal_to_decimal128
+        #   is false, BSON::Decimal128 otherwise.
         def mongoize(object)
-          unless object.nil?
+          return if object.blank?
+          if Mongoid.map_big_decimal_to_decimal128
             if object.is_a?(BSON::Decimal128)
               object
-            elsif Mongoid.map_big_decimal_to_decimal128
-              if object.is_a?(BigDecimal)
-                BSON::Decimal128.new(object)
-              elsif object.numeric?
-                BSON::Decimal128.new(object.to_s)
-              else
-                object.mongoize
-              end
+            elsif object.is_a?(BigDecimal)
+              BSON::Decimal128.new(object)
             elsif object.numeric?
+              BSON::Decimal128.new(object.to_s)
+            else
+              Mongoid::UncastableValue(object, 'BigDecimal')
+            end
+          else
+            if object.is_a?(BSON::Decimal128) || object.numeric?
               object.to_s
+            else
+              Mongoid::UncastableValue(object, 'BigDecimal')
             end
           end
         end

lib/mongoid/extensions/binary.rb

@@ -10,7 +10,7 @@ module Binary
       # @example Mongoize the object.
       #   object.mongoize
       #
-      # @return [ Object ] The object.
+      # @return [ BSON::Binary | nil ] The object.
       def mongoize
         BSON::Binary.mongoize(self)
       end
@@ -24,19 +24,13 @@ module ClassMethods
         #
         # @param [ Object ] object The object to Mongoize
         #
-        # @return [ String | Symbol | BSON::Binary | nil ] A String or Binary
-        #   representing the object or nil.
+        # @return [ BSON::Binary | nil ] A Binary representing the object or nil.
         def mongoize(object)
           return if object.nil?
-
           case object
-          when BSON::Binary
-            object
-          when String, Symbol
-            BSON::Binary.new(object.to_s)
-          else
-            # TODO: MONGOID-5222 raise on the setting of feature flag.
-            nil
+          when BSON::Binary then object
+          when String, Symbol then BSON::Binary.new(object.to_s)
+          else Mongoid::UncastableValue(object, 'BSON::Binary')
           end
         end
       end

lib/mongoid/extensions/boolean.rb

@@ -8,12 +8,19 @@ class << self
       # Turn the object from the ruby type we deal with to a Mongo friendly
       # type.
       #
-      # @example Mongoize the object.
+
       #   Boolean.mongoize("123.11")
       #
-      # @return [ String ] The object mongoized.
+      # @return [ true | false | nil ] The object mongoized or nil.
       def mongoize(object)
-        evolve(object)
+        return if object.nil?
+        if object.to_s =~ (/\A(true|t|yes|y|on|1|1.0)\z/i)
+          true
+        elsif object.to_s =~ (/\A(false|f|no|n|off|0|0.0)\z/i)
+          false
+        else
+          Mongoid::UncastableValue(object, 'Boolean')
+        end
       end
     end
   end