feat(orm): introduce Prism and Orm

lib/prism/orm/serialization.rb

@@ -0,0 +1,111 @@
+module Prism
+  module Orm
+    # Mixed into Relation/HabtmCollection so `json(Post.all)`/`render json:
+    # post.comments` works the same way as a single record: each element is
+    # serialized through Model#as_json (so hide_from_json still applies to
+    # every record in the collection, not just a lone one).
+    module CollectionSerialization
+      def as_json(options = {})
+        to_a.map { |record| record.as_json(options) }
+      end
+
+      def to_json(*args)
+        as_json.to_json(*args)
+      end
+    end
+
+    # ActiveModel::Serialization-lite: turns a record into a plain Hash
+    # (#serializable_hash) or a JSON string (#as_json/#to_json), Rails-style
+    # only:/except:/methods:/include:.
+    #
+    # Before this existed, `render json: record`/`json(record)` fell through
+    # to the stdlib json library's default Object#to_json (String#to_json of
+    # #to_s, e.g. "#<Post:0x...>") and hand-built hashes in controllers had
+    # no protection against leaking a raw column - notably SecurePassword's
+    # digest column, since Model#to_h dumps every attribute unfiltered.
+    # `hide_from_json` closes that: a class can mark a column excluded by
+    # default, and an explicit `only:` naming it is the one way to opt back
+    # in (a deliberate ask overrides the safety net, it does not disable it).
+    module Serialization
+      def self.included(base)
+        base.extend(ClassMethods)
+      end
+
+      module ClassMethods
+        # Same superclass-plus-own fallback as Callbacks#callbacks_for /
+        # Controller#before_actions - a plain `@ivar ||= []` per class would
+        # silently drop a base class's hidden columns in every subclass.
+        def json_hidden_attributes
+          inherited = superclass.respond_to?(:json_hidden_attributes) ? superclass.json_hidden_attributes : []
+          inherited + own_json_hidden_attributes
+        end
+
+        def hide_from_json(*names)
+          own_json_hidden_attributes.concat(names.map(&:to_s))
+        end
+
+        def own_json_hidden_attributes
+          @own_json_hidden_attributes ||= []
+        end
+      end
+
+      def serializable_hash(only: nil, except: nil, methods: nil, include: nil)
+        only_names = only && Array(only).map(&:to_s)
+        except_names = Array(except).map(&:to_s)
+        hidden = self.class.json_hidden_attributes
+
+        hash = to_h.each_with_object({}) do |(key, value), acc|
+          allowed = only_names ? only_names.include?(key) : !hidden.include?(key) && !except_names.include?(key)
+          acc[key] = value if allowed
+        end
+
+        Array(methods).each { |name| hash[name.to_s] = send(name) }
+        merge_included_associations(hash, include) if include
+        hash
+      end
+
+      def as_json(options = {})
+        jsonify(serializable_hash(**options))
+      end
+
+      def to_json(*args)
+        as_json.to_json(*args)
+      end
+
+      private
+
+      def jsonify(value)
+        case value
+        when Hash then value.transform_values { |nested| jsonify(nested) }
+        when Array then value.map { |nested| jsonify(nested) }
+        when Time, Date, DateTime then value.iso8601
+        else value
+        end
+      end
+
+      def merge_included_associations(hash, include)
+        normalize_include(include).each do |name, nested_options|
+          associated = send(name)
+          hash[name.to_s] = serialize_association(associated, nested_options || {})
+        end
+      end
+
+      def serialize_association(associated, nested_options)
+        if associated.is_a?(Model)
+          associated.serializable_hash(**nested_options)
+        elsif associated.respond_to?(:map)
+          associated.map { |record| record.serializable_hash(**nested_options) }
+        end
+      end
+
+      def normalize_include(include)
+        case include
+        when Symbol, String then { include.to_sym => nil }
+        when Array then include.each_with_object({}) { |name, acc| acc[name.to_sym] = nil }
+        when Hash then include
+        else {}
+        end
+      end
+    end
+  end
+end