active_model_serializers/test/cache_test.rb

require 'test_helper'
require 'tmpdir'
require 'tempfile'

module ActiveModelSerializers
  class CacheTest < ActiveSupport::TestCase
    UncachedAuthor = Class.new(Author) do
      # To confirm cache_key is set using updated_at and cache_key option passed to cache
      undef_method :cache_key
    end

    Article = Class.new(::Model) do
      # To confirm error is raised when cache_key is not set and cache_key option not passed to cache
      undef_method :cache_key
    end

    ArticleSerializer = Class.new(ActiveModel::Serializer) do
      cache only: [:place], skip_digest: true
      attributes :title
    end

    InheritedRoleSerializer = Class.new(RoleSerializer) do
      cache key: 'inherited_role', only: [:name, :special_attribute]
      attribute :special_attribute
    end

    setup do
      cache_store.clear
      @comment        = Comment.new(id: 1, body: 'ZOMG A COMMENT')
      @post           = Post.new(title: 'New Post', body: 'Body')
      @bio            = Bio.new(id: 1, content: 'AMS Contributor')
      @author         = Author.new(name: 'Joao M. D. Moura')
      @blog           = Blog.new(id: 999, name: 'Custom blog', writer: @author, articles: [])
      @role           = Role.new(name: 'Great Author')
      @location       = Location.new(lat: '-23.550520', lng: '-46.633309')
      @place          = Place.new(name: 'Amazing Place')
      @author.posts   = [@post]
      @author.roles   = [@role]
      @role.author    = @author
      @author.bio     = @bio
      @bio.author     = @author
      @post.comments  = [@comment]
      @post.author    = @author
      @comment.post   = @post
      @comment.author = @author
      @post.blog      = @blog
      @location.place = @place

      @location_serializer = LocationSerializer.new(@location)
      @bio_serializer      = BioSerializer.new(@bio)
      @role_serializer     = RoleSerializer.new(@role)
      @post_serializer     = PostSerializer.new(@post)
      @author_serializer   = AuthorSerializer.new(@author)
      @comment_serializer  = CommentSerializer.new(@comment)
      @blog_serializer     = BlogSerializer.new(@blog)
    end

    def test_explicit_cache_store
      default_store = Class.new(ActiveModel::Serializer) do
        cache
      end
      explicit_store = Class.new(ActiveModel::Serializer) do
        cache cache_store: ActiveSupport::Cache::FileStore
      end

      assert ActiveSupport::Cache::MemoryStore, ActiveModelSerializers.config.cache_store
      assert ActiveSupport::Cache::MemoryStore, default_store.cache_store
      assert ActiveSupport::Cache::FileStore, explicit_store.cache_store
    end

    def test_inherited_cache_configuration
      inherited_serializer = Class.new(PostSerializer)

      assert_equal PostSerializer._cache_key, inherited_serializer._cache_key
      assert_equal PostSerializer._cache_options, inherited_serializer._cache_options
    end

    def test_override_cache_configuration
      inherited_serializer = Class.new(PostSerializer) do
        cache key: 'new-key'
      end

      assert_equal PostSerializer._cache_key, 'post'
      assert_equal inherited_serializer._cache_key, 'new-key'
    end

    def test_cache_definition
      assert_equal(cache_store, @post_serializer.class._cache)
      assert_equal(cache_store, @author_serializer.class._cache)
      assert_equal(cache_store, @comment_serializer.class._cache)
    end

    def test_cache_key_definition
      assert_equal('post', @post_serializer.class._cache_key)
      assert_equal('writer', @author_serializer.class._cache_key)
      assert_equal(nil, @comment_serializer.class._cache_key)
    end

    def test_cache_key_interpolation_with_updated_at_when_cache_key_is_not_defined_on_object
      uncached_author            = UncachedAuthor.new(name: 'Joao M. D. Moura')
      uncached_author_serializer = AuthorSerializer.new(uncached_author)

      render_object_with_cache(uncached_author)
      key = "#{uncached_author_serializer.class._cache_key}/#{uncached_author_serializer.object.id}-#{uncached_author_serializer.object.updated_at.strftime("%Y%m%d%H%M%S%9N")}"
      assert_equal(uncached_author_serializer.attributes.to_json, cache_store.fetch(key).to_json)
    end

    def test_default_cache_key_fallback
      render_object_with_cache(@comment)
      key = @comment.cache_key
      assert_equal(@comment_serializer.attributes.to_json, cache_store.fetch(key).to_json)
    end

    def test_error_is_raised_if_cache_key_is_not_defined_on_object_or_passed_as_cache_option
      article = Article.new(title: 'Must Read')
      e = assert_raises ActiveModelSerializers::CachedSerializer::UndefinedCacheKey do
        render_object_with_cache(article)
      end
      assert_match(/ActiveModelSerializers::CacheTest::Article must define #cache_key, or the 'key:' option must be passed into 'CachedActiveModelSerializers_CacheTest_ArticleSerializer.cache'/, e.message)
    end

    def test_cache_options_definition
      assert_equal({ expires_in: 0.1, skip_digest: true }, @post_serializer.class._cache_options)
      assert_equal(nil, @blog_serializer.class._cache_options)
      assert_equal({ expires_in: 1.day, skip_digest: true }, @comment_serializer.class._cache_options)
    end

    def test_fragment_cache_definition
      assert_equal([:name], @role_serializer.class._cache_only)
      assert_equal([:content], @bio_serializer.class._cache_except)
    end

    def test_associations_separately_cache
      cache_store.clear
      assert_equal(nil, cache_store.fetch(@post.cache_key))
      assert_equal(nil, cache_store.fetch(@comment.cache_key))

      Timecop.freeze(Time.current) do
        render_object_with_cache(@post)

        key = @post.cache_key
        assert_equal(@post_serializer.attributes, cache_store.fetch(key))
        key = @comment.cache_key
        assert_equal(@comment_serializer.attributes, cache_store.fetch(key))
      end
    end

    def test_associations_cache_when_updated
      Timecop.freeze(Time.current) do
        # Generate a new Cache of Post object and each objects related to it.
        render_object_with_cache(@post)

        # Check if it cached the objects separately
        key = @post.cache_key
        assert_equal(@post_serializer.attributes, cache_store.fetch(key))
        key = @comment.cache_key
        assert_equal(@comment_serializer.attributes, cache_store.fetch(key))

        # Simulating update on comments relationship with Post
        new_comment            = Comment.new(id: 2567, body: 'ZOMG A NEW COMMENT')
        new_comment_serializer = CommentSerializer.new(new_comment)
        @post.comments         = [new_comment]

        # Ask for the serialized object
        render_object_with_cache(@post)

        # Check if the the new comment was cached
        key = new_comment.cache_key
        assert_equal(new_comment_serializer.attributes, cache_store.fetch(key))
        key = @post.cache_key
        assert_equal(@post_serializer.attributes, cache_store.fetch(key))
      end
    end

    def test_fragment_fetch_with_virtual_associations
      expected_result = {
        id: @location.id,
        lat: @location.lat,
        lng: @location.lng,
        place: 'Nowhere'
      }

      hash = render_object_with_cache(@location)

      assert_equal(hash, expected_result)
      assert_equal({ place: 'Nowhere' }, cache_store.fetch(@location.cache_key))
    end

    def test_fragment_cache_with_inheritance
      inherited = render_object_with_cache(@role, serializer: InheritedRoleSerializer)
      base = render_object_with_cache(@role)

      assert_includes(inherited.keys, :special_attribute)
      refute_includes(base.keys, :special_attribute)
    end

    def test_uses_file_digest_in_cache_key
      render_object_with_cache(@blog)
      key = "#{@blog.cache_key}/#{::Model::FILE_DIGEST}"
      assert_equal(@blog_serializer.attributes, cache_store.fetch(key))
    end

    def test_cache_digest_definition
      assert_equal(::Model::FILE_DIGEST, @post_serializer.class._cache_digest)
    end

    def test_object_cache_keys
      serializer = ActiveModel::Serializer::CollectionSerializer.new([@comment, @comment])
      include_tree = ActiveModel::Serializer::IncludeTree.from_include_args('*')

      actual = CachedSerializer.object_cache_keys(serializer, include_tree)

      assert_equal actual.size, 3
      assert actual.any? { |key| key == 'comment/1' }
      assert actual.any? { |key| key =~ %r{post/post-\d+} }
      assert actual.any? { |key| key =~ %r{author/author-\d+} }
    end

    def test_cached_attributes
      serializer = ActiveModel::Serializer::CollectionSerializer.new([@comment, @comment])

      Timecop.freeze(Time.current) do
        render_object_with_cache(@comment)

        attributes = Adapter::Attributes.new(serializer)
        attributes.send(:cache_attributes)
        cached_attributes = attributes.instance_variable_get(:@cached_attributes)

        assert_equal cached_attributes[@comment.cache_key], Comment.new(id: 1, body: 'ZOMG A COMMENT').attributes
        assert_equal cached_attributes[@comment.post.cache_key], Post.new(id: 'post', title: 'New Post', body: 'Body').attributes

        writer = @comment.post.blog.writer
        writer_cache_key = writer.cache_key

        assert_equal cached_attributes[writer_cache_key], Author.new(id: 'author', name: 'Joao M. D. Moura').attributes
      end
    end

    def test_serializer_file_path_on_nix
      path = '/Users/git/emberjs/ember-crm-backend/app/serializers/lead_serializer.rb'
      caller_line = "#{path}:1:in `<top (required)>'"
      assert_equal caller_line[ActiveModel::Serializer::CALLER_FILE], path
    end

    def test_serializer_file_path_on_windows
      path = 'c:/git/emberjs/ember-crm-backend/app/serializers/lead_serializer.rb'
      caller_line = "#{path}:1:in `<top (required)>'"
      assert_equal caller_line[ActiveModel::Serializer::CALLER_FILE], path
    end

    def test_serializer_file_path_with_space
      path = '/Users/git/ember js/ember-crm-backend/app/serializers/lead_serializer.rb'
      caller_line = "#{path}:1:in `<top (required)>'"
      assert_equal caller_line[ActiveModel::Serializer::CALLER_FILE], path
    end

    def test_serializer_file_path_with_submatch
      # The submatch in the path ensures we're using a correctly greedy regexp.
      path = '/Users/git/ember js/ember:123:in x/app/serializers/lead_serializer.rb'
      caller_line = "#{path}:1:in `<top (required)>'"
      assert_equal caller_line[ActiveModel::Serializer::CALLER_FILE], path
    end

    def test_digest_caller_file
      contents = "puts 'AMS rocks'!"
      dir = Dir.mktmpdir('space char')
      file = Tempfile.new('some_ruby.rb', dir)
      file.write(contents)
      path = file.path
      caller_line = "#{path}:1:in `<top (required)>'"
      file.close
      assert_equal ActiveModel::Serializer.digest_caller_file(caller_line), Digest::MD5.hexdigest(contents)
    ensure
      file.unlink
      FileUtils.remove_entry dir
    end

    def test_warn_on_serializer_not_defined_in_file
      called = false
      serializer = Class.new(ActiveModel::Serializer)
      assert_output(nil, /_cache_digest/) do
        serializer.digest_caller_file('')
        called = true
      end
      assert called
    end

    private

    def render_object_with_cache(obj, options = {})
      serializable(obj, options).serializable_hash
    end

    def cache_store
      ActiveModelSerializers.config.cache_store
    end

    def cached_serialization(serializer)
      cache_key = CachedSerializer.new(serializer).cache_key
      cache_store.fetch(cache_key)
    end
  end
end