MONGOID-5474 add readonly! and raise on save/update (#5455)

* MONGOID-5474 add readonly! and raise on save/update

* MONGOID-5474 flip flag for 9.0 and add default

* MONGOID-5474 fix error tests

* Update spec/mongoid/config_spec.rb

* Apply suggestions from code review

Co-authored-by: Oleg Pudeyev <39304720+p-mongo@users.noreply.github.com>

* Update lib/mongoid/config.rb

Co-authored-by: Oleg Pudeyev <39304720+p-mongo@users.noreply.github.com>

Co-authored-by: Oleg Pudeyev <39304720+p-mongo@users.noreply.github.com>

Author: neilshweky

lib/config/locales/en.yml

@@ -567,9 +567,8 @@ en:
           resolution: "Don't define '%{name}' as readonly, or do not attempt
             to update its value after the document is persisted."
         readonly_document:
-          message: "Attempted to persist the readonly document '%{klass}'."
-          summary: "Documents loaded from the database using #only
-            cannot be persisted."
+          message: "Attempted to persist a readonly document of class '%{klass}'."
+          summary: "Documents that are marked readonly cannot be persisted."
           resolution: "Don't attempt to persist documents that are flagged as
             readonly."
         scope_overwrite:

lib/mongoid/config.rb

@@ -127,6 +127,16 @@ module Config
     # always return a Hash.
     option :legacy_attributes, default: false
 
+    # When this flag is true, a document is only readonly if it has been
+    # projected using #only or #without, and readonly documents will not
+    # be deletable/destroyable. When this flag is false, a document will
+    # become readonly only once the #readonly! method is called, and an error
+    # will be raised on attempting to save or update such documents, instead
+    # of just on delete.
+    # When this feature flag is turned on, the readonly state will be reset on
+    # reload, but when it is turned off, it won't be.
+    option :legacy_readonly, default: false
+
     # Returns the Config singleton, for use in the configure DSL.
     #
     # @return [ self ] The Config singleton.

lib/mongoid/config/defaults.rb

@@ -19,7 +19,7 @@ def load_defaults(version)
         # versions are to give old functionality. Because of this, it is
         # possible to recurse to later version to get all of the options to
         # turn off. Note that this won't be true when adding feature flags to
-        # 8.1, since the default will be the old functionality until the next
+        # 9.x, since the default will be the old functionality until the next
         # major version is released. More likely, the recursion will have to go
         # in the other direction (towards earlier versions).
 
@@ -48,6 +48,7 @@ def load_defaults(version)
           self.map_big_decimal_to_decimal128 = false
         when "8.0"
           # All flag defaults currently reflect 8.0 behavior.
+          self.legacy_readonly = true
         when "8.1"
           # All flag defaults currently reflect 8.1 behavior.
         when "9.0"

lib/mongoid/persistable.rb

@@ -180,6 +180,7 @@ def post_process_persist(result, options = {})
     #
     # @return [ Object ] The result of the operation.
     def prepare_atomic_operation
+      raise Errors::ReadonlyDocument.new(self.class) if readonly? && !Mongoid.legacy_readonly
       operations = yield({})
       persist_or_delay_atomic_operation(operations)
       self

lib/mongoid/persistable/creatable.rb

@@ -100,6 +100,7 @@ def post_process_insert
       #
       # @return [ Document ] The document.
       def prepare_insert(options = {})
+        raise Errors::ReadonlyDocument.new(self.class) if readonly? && !Mongoid.legacy_readonly
         return self if performing_validations?(options) &&
           invalid?(options[:context] || :create)
         run_callbacks(:save, with_children: false) do

lib/mongoid/persistable/deletable.rb

@@ -16,7 +16,6 @@ module Deletable
       #
       # @return [ TrueClass ] True.
       def delete(options = {})
-        raise Errors::ReadonlyDocument.new(self.class) if readonly?
         prepare_delete do
           unless options[:persist] == false
             if embedded?
@@ -102,6 +101,7 @@ def notifying_parent?(options = {})
       #
       # @return [ Object ] The result of the block.
       def prepare_delete
+        raise Errors::ReadonlyDocument.new(self.class) if readonly?
         yield(self)
         freeze
         self.destroyed = true

lib/mongoid/persistable/updatable.rb

@@ -96,6 +96,7 @@ def init_atomic_updates
       #
       # @return [ true | false ] The result of the update.
       def prepare_update(options = {})
+        raise Errors::ReadonlyDocument.new(self.class) if readonly? && !Mongoid.legacy_readonly
         return false if performing_validations?(options) &&
           invalid?(options[:context] || :update)
         process_flagged_destroys

lib/mongoid/persistable/upsertable.rb

@@ -38,6 +38,7 @@ def upsert(options = {})
       #
       # @return [ true | false ] If the operation succeeded.
       def prepare_upsert(options = {})
+        raise Errors::ReadonlyDocument.new(self.class) if readonly? && !Mongoid.legacy_readonly
         return false if performing_validations?(options) && invalid?(:upsert)
         result = run_callbacks(:upsert) do
           yield(self)

lib/mongoid/stateful.rb

@@ -95,14 +95,35 @@ def pushable?
         !_parent.delayed_atomic_sets[atomic_path]
     end
 
+    # Flags the document as readonly. Will cause a ReadonlyDocument error to be
+    # raised if the document is attempted to be saved, updated or destroyed.
+    #
+    # @example Flag the document as readonly.
+    #   document.readonly!
+    #
+    # @return [ true | false ] true if the document was successfully marked
+    #   readonly, false otherwise.
+    def readonly!
+      if Mongoid.legacy_readonly
+        Mongoid::Warnings.warn_legacy_readonly
+        false
+      else
+        @readonly = true
+      end
+    end
+
     # Is the document readonly?
     #
     # @example Is the document readonly?
     #   document.readonly?
     #
     # @return [ true | false ] If the document is readonly.
     def readonly?
-      __selected_fields != nil
+      if Mongoid.legacy_readonly
+        __selected_fields != nil
+      else
+        @readonly ||= false
+      end
     end
 
     # Determine if the document can be set.

lib/mongoid/warnings.rb

@@ -24,5 +24,6 @@ def warning(id, message)
     warning :geo_haystack_deprecated, 'The geoHaystack type is deprecated.'
     warning :as_json_compact_deprecated, '#as_json :compact option is deprecated. Please call #compact on the returned Hash object instead.'
     warning :symbol_type_deprecated, 'The BSON Symbol type is deprecated by MongoDB. Please use String or StringifiedSymbol field types instead of the Symbol field type'
+    warning :legacy_readonly, 'The readonly! method will only mark the document readonly when the legacy_readonly feature flag is switched off.'
   end
 end