MONGOID-5467 MONGOID-5320 Change usage of ActiveModel::MissingAttributeError to Mongoid::Errors:AttributeNotLoaded (#5437)

* Change usage of ActiveModel::MissingAttributeError to Mongoid::Errors::AttributeNotLoaded.

* Fix specs

* Improve release notes

Co-authored-by: shields <[email protected]>

Author: johnnyshields

docs/reference/crud.txt

@@ -657,7 +657,7 @@ Mongoid provides several ways of accessing field values.
 .. note::
 
   All of the access methods described below raise
-  ``ActiveModel::MissingAttributeError`` when the field being accessed is
+  ``Mongoid::Errors::AttributeNotLoaded`` when the field being accessed is
   :ref:`projected out <projection>`, either by virtue of not being included in
   :ref:`only <only>` or by virtue of being included in
   :ref:`without <without>`. This applies to both reads and writes.

docs/reference/queries.txt

@@ -775,12 +775,12 @@ operation is sometimes called "projection".
   band = Band.only(:name).first
 
 Attempting to reference attributes which have not been loaded results in
-``ActiveModel::MissingAttributeError``.
+``Mongoid::Errors::AttributeNotLoaded``.
 
 .. code-block:: ruby
 
   band.label
-  # ActiveModel::MissingAttributeError (Missing attribute: 'label'.)
+  #=> raises Mongoid::Errors::AttributeNotLoaded
 
 Even though Mongoid currently allows writing to attributes that have not
 been loaded, such writes will not be persisted

docs/release-notes/mongoid-9.0.txt

@@ -0,0 +1,42 @@
+***********
+Mongoid 9.0
+***********
+
+.. default-domain:: mongodb
+
+.. contents:: On this page
+   :local:
+   :backlinks: none
+   :depth: 2
+   :class: singlecol
+
+This page describes significant changes and improvements in Mongoid 9.0.
+The complete list of releases is available `on GitHub
+<https://github.com/mongodb/mongoid/releases>`_ and `in JIRA
+<https://jira.mongodb.org/projects/MONGOID?selectedItem=com.atlassian.jira.jira-projects-plugin:release-page>`_;
+please consult GitHub releases for detailed release notes and JIRA for
+the complete list of issues fixed in each release, including bug fixes.
+
+
+Raise AttributeNotLoaded error when accessing fields omitted from query projection
+----------------------------------------------------------------------------------
+
+When attempting to access a field on a model instance which was
+excluded with the ``.only`` or ``.without`` query projections methods
+when the instance was loaded, Mongoid will now raise a
+``Mongoid::Errors::AttributeNotLoaded`` error.
+
+.. code-block:: ruby
+
+  Band.only(:name).first.label
+  #=> raises Mongoid::Errors::AttributeNotLoaded
+
+  Band.without(:label).first.label = 'Sub Pop Records'
+  #=> raises Mongoid::Errors::AttributeNotLoaded
+
+In earlier Mongoid versions, the same conditions would raise an
+``ActiveModel::MissingAttributeError``. Please check your code for
+any Mongoid-specific usages of this class, and change them to
+``Mongoid::Errors::AttributeNotLoaded``. Note additionally that
+``AttributeNotLoaded`` inherits from ``Mongoid::Errors::MongoidError``,
+while ``ActiveModel::MissingAttributeError`` does not.

lib/config/locales/en.yml

@@ -23,6 +23,17 @@ en:
           resolution: "On the %{name} association on %{inverse} you must add an
             :inverse_of option to specify the exact association on %{klass}
             that is the opposite of %{name}."
+        attribute_not_loaded:
+          message: "Attempted to access attribute '%{name}' on %{klass} which
+            was not loaded."
+          summary:
+            "You loaded an instance of %{klass} using a query projection method
+            such as `.only` or `.without`, then attempted to read or write an
+            attribute '%{name}' which was not included in the projection.
+            Mongoid intentionally prevents this to avoid overwriting data."
+          resolution: "Ensure your query projection methods such as `.only` and
+            `.without` include field '%{name}' when loading instances of %{klass},
+            or remove such projections methods entirely."
         callbacks:
           message: "Calling %{method} on %{klass} resulted in a false return
             from a callback."

lib/mongoid/association/accessors.rb

@@ -115,7 +115,7 @@ def get_relation(name, association, object, reload = false)
         # during binding or when cascading callbacks. Whenever we retrieve
         # associations within the codebase, we use without_autobuild.
         if !without_autobuild? && association.embedded? && attribute_missing?(field_name)
-          raise ActiveModel::MissingAttributeError, "Missing attribute: '#{field_name}'"
+          raise Mongoid::Errors::AttributeNotLoaded.new(self.class, field_name)
         end
 
         if !reload && (value = ivar(name)) != false

lib/mongoid/attributes.rb

@@ -31,7 +31,7 @@ module Attributes
     def attribute_present?(name)
       attribute = read_raw_attribute(name)
       !attribute.blank? || attribute == false
-    rescue ActiveModel::MissingAttributeError
+    rescue Mongoid::Errors::AttributeNotLoaded
       false
     end
 
@@ -165,7 +165,7 @@ def write_attribute(name, value)
       field_name = database_field_name(name)
 
       if attribute_missing?(field_name)
-        raise ActiveModel::MissingAttributeError, "Missing attribute: '#{name}'"
+        raise Mongoid::Errors::AttributeNotLoaded.new(self.class, field_name)
       end
 
       if attribute_writable?(field_name)
@@ -291,7 +291,7 @@ def read_raw_attribute(name)
       normalized = database_field_name(name.to_s)
 
       if attribute_missing?(normalized)
-        raise ActiveModel::MissingAttributeError, "Missing attribute: '#{name}'"
+        raise Mongoid::Errors::AttributeNotLoaded.new(self.class, name)
       end
 
       if hash_dot_syntax?(normalized)

lib/mongoid/errors.rb

@@ -2,6 +2,7 @@
 
 require "mongoid/errors/mongoid_error"
 require "mongoid/errors/ambiguous_relationship"
+require "mongoid/errors/attribute_not_loaded"
 require "mongoid/errors/callback"
 require "mongoid/errors/criteria_argument_required"
 require "mongoid/errors/document_not_destroyed"

lib/mongoid/errors/attribute_not_loaded.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Mongoid
+  module Errors
+
+    # Raised when attempting to read or write an attribute which has
+    # not been loaded. This can occur when using `.only` or `.without`
+    # query projection methods.
+    #
+    # @example Getting a field which has not been loaded.
+    #   Band.only(:name).first.label
+    #   #=> raises Mongoid::Errors::AttributeNotLoaded
+    #
+    # @example Setting a field which has not been loaded.
+    #   Band.without(:label).first.label = 'Sub Pop Records'
+    #   #=> raises Mongoid::Errors::AttributeNotLoaded
+    class AttributeNotLoaded < MongoidError
+
+      # Create the new error.
+      #
+      # @example Instantiate the error.
+      #   AttributeNotLoaded.new(Person, "title")
+      #
+      # @param [ Class ] klass The model class.
+      # @param [ String | Symbol ] name The name of the attribute.
+      def initialize(klass, name)
+        super(
+          compose_message("attribute_not_loaded", { klass: klass.name, name: name })
+        )
+      end
+    end
+  end
+end

spec/mongoid/association/accessors_spec.rb

@@ -625,7 +625,7 @@
           it 'does not create an accessor for another field on the embedded document' do
             expect do
               persisted_person.passport.country
-            end.to raise_error(ActiveModel::MissingAttributeError)
+            end.to raise_error(Mongoid::Errors::AttributeNotLoaded, /Attempted to access attribute 'country' on Passport which was not loaded/)
           end
         end
 
@@ -655,7 +655,7 @@
               it 'does not create an accessor for another field on the embedded document' do
                 expect do
                   persisted_person.passport.country
-                end.to raise_error(ActiveModel::MissingAttributeError)
+                end.to raise_error(Mongoid::Errors::AttributeNotLoaded, /Attempted to access attribute 'country' on Passport which was not loaded/)
               end
             end
 
@@ -717,7 +717,7 @@
           it 'does not create an accessor for another field on the embedded document' do
             expect do
               persisted_person.phone_numbers.first.landline
-            end.to raise_error(ActiveModel::MissingAttributeError)
+            end.to raise_error(Mongoid::Errors::AttributeNotLoaded, /Attempted to access attribute 'landline' on Phone which was not loaded/)
           end
         end
 
@@ -746,7 +746,7 @@
               it 'does not create an accessor for another field on the embedded document' do
                 expect do
                   persisted_person.phone_numbers.first.landline
-                end.to raise_error(ActiveModel::MissingAttributeError)
+                end.to raise_error(Mongoid::Errors::AttributeNotLoaded, /Attempted to access attribute 'landline' on Phone which was not loaded/)
               end
 
             end

spec/mongoid/association/embedded/embeds_many_query_spec.rb

@@ -23,7 +23,7 @@
       # has a default value specified in the model
       expect do
         legislator.b
-      end.to raise_error(ActiveModel::MissingAttributeError)
+      end.to raise_error(Mongoid::Errors::AttributeNotLoaded, /Attempted to access attribute 'b' on EmmLegislator which was not loaded/)
       expect(legislator.attributes.keys).to eq(['_id', 'a'])
     end
 
@@ -53,10 +53,10 @@
         EmmCongress.where(name: 'foo').only(:_id).first
       end
 
-      it 'raises a MissingAttributeError' do
+      it 'raises AttributeNotLoaded' do
         expect do
           congress.legislators
-        end.to raise_error(ActiveModel::MissingAttributeError)
+        end.to raise_error(Mongoid::Errors::AttributeNotLoaded, /Attempted to access attribute 'legislators' on EmmCongress which was not loaded/)
       end
     end
   end