Prefetch relationships according to JSONAPI include

ams_lazy_relationships.gemspec

@@ -35,6 +35,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency "active_model_serializers"
   spec.add_dependency "batch-loader", "~> 1.2"
+  spec.add_dependency "jsonapi-renderer"
 
   spec.add_development_dependency "activerecord"
   # A Ruby library for testing against different versions of dependencies

lib/ams_lazy_relationships/core.rb

@@ -43,9 +43,11 @@ module Initializer
     def initialize(object, options = {})
       super
 
-      # binding.pry
-      # self.class.include_directive_from_options(@instance_options)
-      self.class.send(:load_all_lazy_relationships, self, options.fetch(:level, 0))
+      prefetch = options.fetch(:prefetch) {
+        self.class.include_directive_from_options(@instance_options)
+      }
+
+      self.class.send(:load_all_lazy_relationships, self, prefetch)
     end
   end
 end

lib/ams_lazy_relationships/core/evaluation.rb

@@ -1,41 +1,43 @@
 # frozen_string_literal: true
 
+require "jsonapi/include_directive"
+
 module AmsLazyRelationships::Core
   # Module responsible for lazy loading the relationships during the runtime
   module Evaluation
     private
 
-    LAZY_NESTING_LEVELS = 3
-    NESTING_START_LEVEL = 1
+    DEFAULT_PREFETCH = JSONAPI::IncludeDirective.new("")
 
     # Recursively loads the tree of lazy relationships
     #
     # @param instance [Object] Lazy relationships will be loaded for this serializer.
-    def load_all_lazy_relationships(instance, level = NESTING_START_LEVEL)
+    def load_all_lazy_relationships(instance, prefetch)
       return unless instance.object
-      return if level >= LAZY_NESTING_LEVELS
 
       return unless lazy_relationships
 
-      lazy_relationships.each_value do |lrm|
-        load_lazy_relationship(lrm, instance, level)
+      lazy_relationships.each do |key, lrm|
+        next unless prefetch.key? key
+
+        next_prefetch = prefetch[key]
+        load_lazy_relationship(lrm, instance, next_prefetch)
       end
     end
 
     # @param lrm [LazyRelationshipMeta] relationship data
     # @param instance [Object] Serializer instance to load the relationship for
-    def load_lazy_relationship(lrm, instance, level = NESTING_START_LEVEL)
-
+    def load_lazy_relationship(lrm, instance, prefetch = DEFAULT_PREFETCH)
       lrm.loader.load(instance, lrm.load_for) do |batch_records|
         deep_load_for_yielded_records(
           batch_records,
           lrm,
-          level
+          prefetch
         )
       end
     end
 
-    def deep_load_for_yielded_records(batch_records, lrm, level)
+    def deep_load_for_yielded_records(batch_records, lrm, prefetch)
       # There'll be no more nesting if there's no
       # reflection for this relationship. We can skip deeper lazy loading.
       return unless lrm.reflection
@@ -44,7 +46,7 @@ def deep_load_for_yielded_records(batch_records, lrm, level)
         serializer_class =
           lrm.serializer_class || ActiveModel::Serializer.serializer_for(r)
 
-        serializer_class.new(r, level: level + 1)
+        serializer_class.new(r, prefetch: prefetch)
       end
     end
   end