jsonapi-serializer · stas · Oct 21, 2020
diff --git a/.rubocop.yml b/.rubocop.yml
@@ -2,6 +2,9 @@ require:
   - rubocop-performance
   - rubocop-rspec
 
+AllCops:
+    NewCops: enable
+
 Style/FrozenStringLiteralComment:
   Enabled: false
 
@@ -38,41 +41,25 @@ Performance/TimesMap:
   Exclude:
     - 'spec/**/**.rb'
 
-# TODO: Fix these...
-Style/Documentation:
+Metrics/ModuleLength:
   Enabled: false
 
-Style/GuardClause:
-  Exclude:
-    - 'lib/**/**.rb'
-
-Style/ConditionalAssignment:
-  Exclude:
-    - 'lib/**/**.rb'
-
-Style/IfUnlessModifier:
-  Exclude:
-    - 'lib/**/**.rb'
-
-Lint/AssignmentInCondition:
-  Exclude:
-    - 'lib/**/**.rb'
-
-Metrics:
+Metrics/BlockLength:
   Exclude:
-    - 'lib/**/**.rb'
+    - 'spec/**/**.rb'
 
-Metrics/BlockLength:
+Metrics/MethodLength:
   Enabled: false
 
-Layout/LineLength:
-  Exclude:
-    - 'lib/**/**.rb'
+Metrics/CyclomaticComplexity:
+  Max: 12
 
-Naming/PredicateName:
-  Exclude:
-    - 'lib/**/**.rb'
+Metrics/PerceivedComplexity:
+  Max: 12
+
+Metrics/AbcSize:
+  Max: 36
 
 Naming/AccessorMethodName:
   Exclude:
-    - 'lib/**/**.rb'
+    - '**/**/dsl.rb'
diff --git a/jsonapi-serializer.gemspec b/jsonapi-serializer.gemspec
@@ -19,9 +19,7 @@ Gem::Specification.new do |gem|
   gem.require_paths = ['lib']
   gem.extra_rdoc_files = ['LICENSE.txt', 'README.md']
 
-  gem.add_runtime_dependency('activesupport', '>= 4.2')
-
-  gem.add_development_dependency('activerecord')
+  gem.add_development_dependency('dry-inflector')
   gem.add_development_dependency('bundler')
   gem.add_development_dependency('byebug')
   gem.add_development_dependency('ffaker')
@@ -33,4 +31,5 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency('rubocop-rspec')
   gem.add_development_dependency('simplecov')
   gem.add_development_dependency('sqlite3')
+  gem.add_development_dependency('activesupport')
 end
diff --git a/lib/jsonapi/serializer.rb b/lib/jsonapi/serializer.rb
@@ -1,12 +1,67 @@
-require 'fast_jsonapi'
+require 'jsonapi/serializer/base'
+require 'jsonapi/serializer/core'
+require 'jsonapi/serializer/dsl'
+require 'jsonapi/serializer/errors'
+require 'jsonapi/serializer/trackable'
 
+# Provides JSONAPI related functionality
 module JSONAPI
+  # Provides JSONAPI serialization functionality
   module Serializer
-    # TODO: Move and cleanup the old implementation...
+    extend Trackable
+
+    # Self registers any inherited/extended class to keep track of it
+    #
+    # @return nothing
     def self.included(base)
+      super
+
+      register_serializer(base)
+
       base.class_eval do
-        include FastJsonapi::ObjectSerializer
+        include ::JSONAPI::Serializer::Base
+        extend ::JSONAPI::Serializer::DSL
+        extend ::JSONAPI::Serializer::Core
       end
     end
+
+    # Serializes an object or a collection
+    #
+    # The `options` are passed to the serializer instance and follow the
+    # same purpose.
+    #
+    # The only extra option is the `options[:serializers]`
+    # one can use to pass a mapping of object to serializer classes to
+    # be strict about how each object is serialized.
+    #
+    # @param object_or_collection [Object] to be serialized
+    # @param options [Hash] serialization parameters
+    # @return [Hash] of serialized JSONAPI data
+    def self.serialize(object_or_collection, options: nil)
+      options = options.dup || {}
+      serializers = options.delete(:serializers)
+      is_col = options[:is_collection] = collection?(
+        object_or_collection, force: options[:is_collection]
+      )
+
+      serializer = for_object(object_or_collection.first, serializers) if is_col
+      serializer ||= for_object(object_or_collection, serializers)
+
+      serializer.new(object_or_collection, options).serializable_hash
+    end
+
+    # Detects a collection/enumerable
+    #
+    # @param resource [Object] to detect
+    # @return [TrueClass] on a successful detection
+    def self.collection?(resource, force: nil)
+      return force unless force.nil?
+
+      # Rails 4 does not use [Enumerable]...
+      active_record = defined?(ActiveRecord::Relation)
+      return true if active_record && resource.is_a?(ActiveRecord::Relation)
+
+      resource.is_a?(Enumerable) && !resource.respond_to?(:each_pair)
+    end
   end
 end
diff --git a/lib/jsonapi/serializer/base.rb b/lib/jsonapi/serializer/base.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+module JSONAPI
+  module Serializer
+    # Our serializer PORO functionality
+    module Base
+      def initialize(resource, opts = {})
+        @resource = resource
+        @options = opts.dup
+        @params = @options.delete(:params) || {}
+        @fieldsets = @options.delete(:fields) || {}
+        @includes = @options.delete(:include) || []
+        @include = @includes.map(&:to_s).map(&:strip).reject(&:empty?)
+      end
+
+      def serializable_hash
+        is_collection = ::JSONAPI::Serializer.collection?(
+          @resource, force: @options[:is_collection]
+        )
+
+        jsonapi = { data: nil }
+        jsonapi[:data] = [] if is_collection
+        jsonapi[:meta] = @options[:meta] if @options[:meta].is_a?(Hash)
+        jsonapi[:links] = @options[:links] if @options[:links].is_a?(Hash)
+
+        return jsonapi if @resource.nil? || (is_collection && @resource.empty?)
+
+        data = []
+        included = []
+
+        # Used to avoid including duplicate records...
+        included_oids = Set.new
+
+        Array(@resource).each do |record|
+          serializer_class = self.class unless is_collection
+          serializer_class ||= JSONAPI::Serializer.for_object(record)
+
+          fieldset = @fieldsets[serializer_class.record_type]
+          data << serializer_class.record_hash(record, fieldset, @params)
+
+          included += serializer_class.record_includes(
+            record, @includes, included_oids, @fieldsets, @params
+          )
+        end
+
+        jsonapi[:data] = data
+        jsonapi[:data] = data.first unless is_collection
+        jsonapi[:included] = included unless @includes.empty?
+        jsonapi
+      end
+    end
+  end
+end