Merge pull request #5 from DmitryTsepelev/array-types

Add array type generation via Model#to_array_type

.travis.yml

@@ -10,6 +10,7 @@ rvm:
   - ruby-head
 gemfile:
   - gemfiles/rails_5_2.gemfile
+  - gemfiles/rails_6_0.gemfile
   - gemfiles/railsmaster.gemfile
 
 notifications:
@@ -18,9 +19,14 @@ notifications:
 matrix:
   fast_finish: true
   exclude:
+    - rvm: 2.3
+      gemfile: gemfiles/rails_6_0.gemfile
     - rvm: 2.3
       gemfile: gemfiles/railsmaster.gemfile
+    - rvm: 2.4
+      gemfile: gemfiles/rails_6_0.gemfile
     - rvm: 2.4
       gemfile: gemfiles/railsmaster.gemfile
   allow_failures:
     - rvm: ruby-head
+    - gemfile: gemfiles/railsmaster.gemfile

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## master
 
+- [PR #5](https://github.com/DmitryTsepelev/store_model/pull/5) Raise error when `#cast` cannot handle the passed instance ([@DmitryTsepelev][])
+- [PR #5](https://github.com/DmitryTsepelev/store_model/pull/5) Add array type generation via Model#to_array_type ([@DmitryTsepelev][])
+
 ## 0.1.2 (2019-03-14)
 
 - `:store_model` validation should not allow nil by default

Gemfile.local

@@ -0,0 +1,2 @@
+gem "rails", github: "rails/rails"
+gem "sqlite3", "~> 1.4"

README.md

@@ -70,6 +70,18 @@ class Product < ApplicationRecord
 end
 ```
 
+## Handling arrays
+
+Should you store an array of models, you can use `#to_array_type` method:
+
+```ruby
+class Product < ApplicationRecord
+  attribute :configurations, Configuration.to_array_type
+end
+```
+
+After that, your attribute will return array of `Configuration` instances.
+
 ## Validations
 
 `StoreModel` supports all the validations shipped with `ActiveModel`. Start with defining validation for the store model:

gemfiles/rails_6_0.gemfile

@@ -0,0 +1,6 @@
+source "https://rubygems.org"
+
+gem "sqlite3", "~> 1.4.0"
+gem "activerecord", "~> 6.0.0.rc1"
+
+gemspec path: "../"

gemfiles/railsmaster.gemfile

@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
 gem "rails", github: "rails/rails"
-gem "sqlite3", "~> 1.3.6"
+gem "sqlite3", "~> 1.4"
 
 gemspec path: ".."

lib/store_model/model.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "store_model/json_model_type"
+require "store_model/types"
 
 module StoreModel
   module Model
@@ -10,7 +10,11 @@ def self.included(base)
 
       base.extend(Module.new do
         def to_type
-          JsonModelType.new(self)
+          Types::JsonType.new(self)
+        end
+
+        def to_array_type
+          Types::ArrayType.new(self)
         end
       end)
     end

lib/store_model/types.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+require "store_model/types/json_type"
+require "store_model/types/array_type"
+
+module StoreModel
+  module Types
+    class CastError < StandardError; end
+  end
+end

lib/store_model/types/array_type.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require "active_model"
+
+module StoreModel
+  module Types
+    class ArrayType < ActiveModel::Type::Value
+      def initialize(model_klass)
+        @model_klass = model_klass
+      end
+
+      def type
+        :array
+      end
+
+      def cast_value(value)
+        case value
+        when String then decode_and_initialize(value)
+        when Array then ensure_model_class(value)
+        else
+          raise StoreModel::Types::CastError,
+                "failed casting #{value.inspect}, only String or Array instances are allowed"
+        end
+      end
+
+      def serialize(value)
+        case value
+        when Array
+          ActiveSupport::JSON.encode(value)
+        else
+          super
+        end
+      end
+
+      def changed_in_place?(raw_old_value, new_value)
+        cast_value(raw_old_value) != new_value
+      end
+
+      private
+
+      # rubocop:disable Style/RescueModifier
+      def decode_and_initialize(array_value)
+        decoded = ActiveSupport::JSON.decode(array_value) rescue []
+        decoded.map { |attributes| @model_klass.new(attributes) }
+      end
+      # rubocop:enable Style/RescueModifier
+
+      def ensure_model_class(array)
+        array.map do |object|
+          object.is_a?(@model_klass) ? object : @model_klass.new(object)
+        end
+      end
+    end
+  end
+end

lib/store_model/types/json_type.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require "active_model"
+
+module StoreModel
+  module Types
+    class JsonType < ActiveModel::Type::Value
+      def initialize(model_klass)
+        @model_klass = model_klass
+      end
+
+      def type
+        :json
+      end
+
+      def cast_value(value)
+        case value
+        when String then decode_and_initialize(value)
+        when Hash then @model_klass.new(value)
+        when @model_klass then value
+        else
+          raise StoreModel::Types::CastError,
+                "failed casting #{value.inspect}, only String, " \
+                "Hash or #{@model_klass.name} instances are allowed"
+        end
+      end
+
+      def serialize(value)
+        case value
+        when Hash, @model_klass
+          ActiveSupport::JSON.encode(value)
+        else
+          super
+        end
+      end
+
+      def changed_in_place?(raw_old_value, new_value)
+        cast_value(raw_old_value) != new_value
+      end
+
+      private
+
+      # rubocop:disable Style/RescueModifier
+      def decode_and_initialize(value)
+        decoded = ActiveSupport::JSON.decode(value) rescue nil
+        @model_klass.new(decoded) unless decoded.nil?
+      end
+      # rubocop:enable Style/RescueModifier
+    end
+  end
+end

spec/store_model/model_spec.rb

@@ -69,7 +69,7 @@
     end
   end
 
-  describe ".as_type" do
+  describe ".to_type" do
     subject { custom_product_class.new }
 
     let(:custom_product_class) do
@@ -82,4 +82,18 @@
       expect(subject.configuration).to be_a_kind_of(Configuration)
     end
   end
+
+  describe ".to_array_type" do
+    subject { custom_product_class.new }
+
+    let(:custom_product_class) do
+      build_custom_product_class do
+        attribute :configuration, Configuration.to_array_type
+      end
+    end
+
+    it "configures type using field name" do
+      expect(subject.configuration).to be_a_kind_of(Array)
+    end
+  end
 end

spec/store_model/types/array_type_spec.rb

@@ -0,0 +1,96 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+RSpec.describe StoreModel::Types::ArrayType do
+  let(:type) { described_class.new(Configuration) }
+
+  let(:attributes_array) do
+    [
+      {
+        color: "red",
+        disabled_at: Time.new(2019, 2, 22, 12, 30)
+      },
+      {
+        color: "green",
+        disabled_at: Time.new(2019, 3, 12, 8, 10)
+      }
+    ]
+  end
+
+  describe "#type" do
+    subject { type.type }
+
+    it { is_expected.to eq(:array) }
+  end
+
+  describe "#changed_in_place?" do
+    let(:configurations) do
+      attributes_array.map { |attributes| Configuration.new(attributes) }
+    end
+
+    it "marks object as changed" do
+      expect(type.changed_in_place?([], configurations)).to be_truthy
+    end
+  end
+
+  describe "#cast_value" do
+    shared_examples "cast examples" do
+      subject { type.cast_value(value) }
+
+      it { is_expected.to be_a(Array) }
+      it "assigns attributes" do
+        subject.zip(attributes_array).each do |config, config_attributes|
+          expect(config).to have_attributes(config_attributes)
+        end
+      end
+    end
+
+    context "when String is passed" do
+      let(:value) { ActiveSupport::JSON.encode(attributes_array) }
+      include_examples "cast examples"
+    end
+
+    context "when Array of hashes is passed" do
+      let(:value) { attributes_array }
+      include_examples "cast examples"
+    end
+
+    context "when Array of instances is passed" do
+      let(:value) { attributes_array.map { |attrs| Configuration.new(attrs) } }
+      include_examples "cast examples"
+    end
+
+    context "when instance of illegal class is passed" do
+      let(:value) { {} }
+
+      it "raises exception" do
+        expect { type.cast_value(value) }.to raise_error(
+          StoreModel::Types::CastError,
+          "failed casting {}, only String or Array instances are allowed"
+        )
+      end
+    end
+  end
+
+  describe "#serialize" do
+    shared_examples "serialize examples" do
+      subject { type.serialize(value) }
+
+      it { is_expected.to be_a(String) }
+      it "is equal to attributes" do
+        expect(subject).to eq(ActiveSupport::JSON.encode(attributes_array))
+      end
+    end
+
+    context "when Array is passed" do
+      let(:value) { attributes_array }
+      include_examples "serialize examples"
+    end
+
+    context "when String is passed" do
+      let(:value) { ActiveSupport::JSON.encode(attributes_array) }
+      include_examples "serialize examples"
+    end
+  end
+end