[DSL] Implement support for bucket_sort pipeline aggregation

Author: estolfo

lib/elasticsearch/dsl/search/aggregations/pipeline/bucket_sort.rb

@@ -0,0 +1,74 @@
+# Licensed to Elasticsearch B.V. under one or more contributor
+# license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright
+# ownership. Elasticsearch B.V. licenses this file to you under
+# the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#	http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+module Elasticsearch
+  module DSL
+    module Search
+      module Aggregations
+
+        # A parent pipeline aggregation which sorts the buckets of its parent multi-bucket aggregation.
+        #
+        # @example Passing the options as a Hash
+        #
+        #     aggregation :sales_bucket_filter do
+        #       bucket_sort gap_policy: 'insert_zero'
+        #     end
+        #
+        # @example Passing the options as a block
+        #
+        #     aggregation :sales_bucket_sort do
+        #       bucket_sort do
+        #         sort do
+        #           by :total_sales, order: 'desc'
+        #         end
+        #         size 3
+        #       end
+        #     end
+        #
+        # @see https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-pipeline-bucket-sort-aggregation.html
+        #
+        class BucketSort
+          include BaseAggregationComponent
+
+          def sort(*args, &block)
+            if !args.empty? || block
+              @sort = Sort.new(*args, &block)
+              self
+            else
+              @sort
+            end
+          end
+
+          def to_hash
+            call
+
+            if @aggregations
+              @hash[:aggregations] = @aggregations.to_hash
+            end
+
+            @hash[name].merge!(sort: @sort.to_hash) if @sort
+            @hash
+          end
+
+          option_method :from
+          option_method :size
+          option_method :gap_policy
+        end
+      end
+    end
+  end
+end

spec/elasticsearch/dsl/search/aggregations/pipeline/bucket_sort_spec.rb

@@ -0,0 +1,104 @@
+# Licensed to Elasticsearch B.V. under one or more contributor
+# license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright
+# ownership. Elasticsearch B.V. licenses this file to you under
+# the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#	http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+require 'spec_helper'
+
+describe Elasticsearch::DSL::Search::Aggregations::BucketSort do
+
+  let(:search) do
+    described_class.new
+  end
+
+  describe '#to_hash' do
+
+    it 'can be converted to a hash' do
+      expect(search.to_hash).to eq(bucket_sort: {})
+    end
+  end
+
+  context 'when options methods are called' do
+
+    let(:search) do
+      described_class.new
+    end
+
+    describe '#sort' do
+
+      before do
+        search.sort do
+          by :category, order: 'desc'
+        end
+      end
+
+      it 'applies the option' do
+        expect(search.to_hash[:bucket_sort][:sort]).to eq([{ category: { order: 'desc' } }])
+      end
+    end
+
+    describe '#from' do
+
+      before do
+        search.from(5)
+      end
+
+      it 'applies the option' do
+        expect(search.to_hash[:bucket_sort][:from]).to eq(5)
+      end
+    end
+
+    describe '#size' do
+
+      before do
+        search.size(10)
+      end
+
+      it 'applies the option' do
+        expect(search.to_hash[:bucket_sort][:size]).to eq(10)
+      end
+    end
+
+    describe '#gap_policy' do
+
+      before do
+        search.gap_policy('insert_zero')
+      end
+
+      it 'applies the option' do
+        expect(search.to_hash[:bucket_sort][:gap_policy]).to eq('insert_zero')
+      end
+    end
+  end
+
+  describe '#initialize' do
+
+    context 'when a block is provided' do
+
+      let(:search) do
+        described_class.new do
+          sort do
+            by :total_sales, order: 'desc'
+          end
+          size 3
+        end
+      end
+
+      it 'executes the block' do
+        expect(search.to_hash).to eq(bucket_sort: { size: 3, sort: [{ total_sales: { order: 'desc' } }] })
+      end
+    end
+  end
+end