Add context option to .import for passing custom data

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ### New Features
 
+* [#996](https://github.com/toptal/chewy/pull/996): Add `context:` option to `import`/`import!` for passing custom data to crutch blocks and field value procs without redundant DB queries.
+
 ### Changes
 * [#977](https://github.com/toptal/chewy/pull/977): Fewer files on gem installation [@ericproulx](https://github.com/ericproulx).
 

lib/chewy/fields/root.rb

@@ -61,8 +61,8 @@ def compose_id(object)
       # @param fields [Array<Symbol>] a list of fields to compose, every field will be composed if empty
       # @return [Hash] JSON-ready hash with stringified keys
       #
-      def compose(object, crutches = nil, fields: [])
-        result = evaluate([object, crutches])
+      def compose(object, crutches = nil, fields: [], context: {})
+        result = evaluate([object, crutches, context])
 
         if children.present?
           child_fields = if fields.present?
@@ -72,7 +72,7 @@ def compose(object, crutches = nil, fields: [])
           end
 
           child_fields.each_with_object({}) do |field, memo|
-            memo.merge!(field.compose(result, crutches) || {})
+            memo.merge!(field.compose(result, crutches, context) || {})
           end.as_json
         elsif fields.present?
           result.as_json(only: fields, root: false)

lib/chewy/index/crutch.rb

@@ -9,9 +9,12 @@ module Crutch
       end
 
       class Crutches
-        def initialize(index, collection)
+        attr_reader :context
+
+        def initialize(index, collection, context = {})
           @index = index
           @collection = collection
+          @context = context
           @crutches_instances = {}
         end
 
@@ -26,7 +29,14 @@ def respond_to_missing?(name, include_private = false)
         end
 
         def [](name)
-          @crutches_instances[name] ||= @index._crutches[:"#{name}"].call(@collection)
+          @crutches_instances[name] ||= begin
+            block = @index._crutches[:"#{name}"]
+            if block.arity > 1 || block.arity < -1
+              block.call(@collection, @context)
+            else
+              block.call(@collection)
+            end
+          end
         end
       end
 

lib/chewy/index/import.rb

@@ -115,13 +115,13 @@ def bulk(**options)
         # @param crutches [Object] optional crutches object; if omitted - a crutch for the single passed object is created as a fallback
         # @param fields [Array<Symbol>] and array of fields to restrict the generated document
         # @return [Hash] a JSON-ready hash
-        def compose(object, crutches = nil, fields: [])
-          crutches ||= Chewy::Index::Crutch::Crutches.new self, [object]
+        def compose(object, crutches = nil, fields: [], context: {})
+          crutches ||= Chewy::Index::Crutch::Crutches.new self, [object], context
 
           if witchcraft? && root.children.present?
-            cauldron(fields: fields).brew(object, crutches)
+            cauldron(fields: fields).brew(object, crutches, context)
           else
-            root.compose(object, crutches, fields: fields)
+            root.compose(object, crutches, fields: fields, context: context)
           end
         end
 

lib/chewy/index/import/bulk_builder.rb

@@ -13,11 +13,12 @@ class BulkBuilder
         # @param to_index [Array<Object>] objects to index
         # @param delete [Array<Object>] objects or ids to delete
         # @param fields [Array<Symbol, String>] and array of fields for documents update
-        def initialize(index, to_index: [], delete: [], fields: [])
+        def initialize(index, to_index: [], delete: [], fields: [], context: {})
           @index = index
           @to_index = to_index
           @delete = delete
           @fields = fields.map!(&:to_sym)
+          @context = context
         end
 
         # Returns ES API-ready bulk requiest body.
@@ -42,7 +43,7 @@ def index_objects_by_id
       private
 
         def crutches_for_index
-          @crutches_for_index ||= Chewy::Index::Crutch::Crutches.new @index, @to_index
+          @crutches_for_index ||= Chewy::Index::Crutch::Crutches.new @index, @to_index, @context
         end
 
         def index_entry(object)
@@ -257,7 +258,7 @@ def join_field?
         end
 
         def data_for(object, fields: [], crutches: crutches_for_index)
-          @index.compose(object, crutches, fields: fields)
+          @index.compose(object, crutches, fields: fields, context: @context)
         end
 
         def parent_changed?(data, old_parent)

lib/chewy/index/import/routine.rb

@@ -56,6 +56,7 @@ def initialize(index, **options)
               {}
             end
           end
+          @context = @options.delete(:context) || {}
           @errors = []
           @stats = {}
           @leftovers = []
@@ -78,7 +79,7 @@ def create_indexes!
         # @param delete [Array<Object>] any acceptable objects for deleting
         # @return [true, false] the result of the request, true if no errors
         def process(index: [], delete: [])
-          bulk_builder = BulkBuilder.new(@index, to_index: index, delete: delete, fields: @options[:update_fields])
+          bulk_builder = BulkBuilder.new(@index, to_index: index, delete: delete, fields: @options[:update_fields], context: @context)
           bulk_body = bulk_builder.bulk_body
 
           if @options[:journal]

lib/chewy/index/witchcraft.rb

@@ -51,15 +51,15 @@ def initialize(index, fields: [])
           @fields = fields
         end
 
-        def brew(object, crutches = nil)
-          alicorn.call(locals, object, crutches).as_json
+        def brew(object, crutches = nil, context = {})
+          alicorn.call(locals, object, crutches, context).as_json
         end
 
       private
 
         def alicorn
           @alicorn ||= singleton_class.class_eval <<-RUBY, __FILE__, __LINE__ + 1
-            -> (locals, object0, crutches) do
+            -> (locals, object0, crutches, context) do
               #{composed_values(@index.root, 0)}
             end
           RUBY
@@ -182,6 +182,7 @@ def source_for(proc, nesting)
               source = replace_lvar(source, proc_params[n], :"object#{n}") if proc_params[n]
             end
             source = replace_lvar(source, proc_params[nesting + 1], :crutches) if proc_params[nesting + 1]
+            source = replace_lvar(source, proc_params[nesting + 2], :context) if proc_params[nesting + 2]
 
             binding_variable_list(source).each do |variable|
               locals.push(proc.binding.eval(variable.to_s))

spec/chewy/index/import/bulk_builder_spec.rb

@@ -157,6 +157,90 @@ def derived
       end
     end
 
+    context 'context' do
+      before do
+        stub_index(:cities) do
+          crutch :names do |collection, context|
+            context[:names] || collection.to_h { |item| [item.id, "Name#{item.id}"] }
+          end
+
+          field :name, value: ->(o, c) { c.names[o.id] }
+        end
+      end
+
+      let(:to_index) { [double(id: 42)] }
+
+      context 'without context' do
+        specify do
+          expect(subject.bulk_body).to eq([
+            {index: {_id: 42, data: {'name' => 'Name42'}}}
+          ])
+        end
+      end
+
+      context 'with context' do
+        subject { described_class.new(index, to_index: to_index, delete: delete, fields: fields, context: {names: {42 => 'ContextName42'}}) }
+
+        specify do
+          expect(subject.bulk_body).to eq([
+            {index: {_id: 42, data: {'name' => 'ContextName42'}}}
+          ])
+        end
+      end
+
+      context 'with context passed to field value' do
+        before do
+          stub_index(:cities) do
+            crutch :names do |collection|
+              collection.to_h { |item| [item.id, "Name#{item.id}"] }
+            end
+
+            field :name, value: ->(o, crutches, context) { context[:prefix].to_s + crutches.names[o.id] }
+          end
+        end
+
+        context 'without context' do
+          specify do
+            expect(subject.bulk_body).to eq([
+              {index: {_id: 42, data: {'name' => 'Name42'}}}
+            ])
+          end
+        end
+
+        context 'with context' do
+          subject { described_class.new(index, to_index: to_index, delete: delete, fields: fields, context: {prefix: '[ctx] '}) }
+
+          specify do
+            expect(subject.bulk_body).to eq([
+              {index: {_id: 42, data: {'name' => '[ctx] Name42'}}}
+            ])
+          end
+        end
+      end
+
+      context 'witchcraft' do
+        before { CitiesIndex.witchcraft! }
+
+        context 'without context' do
+          specify do
+            expect(subject.bulk_body).to eq([
+              {index: {_id: 42, data: {'name' => 'Name42'}}}
+            ])
+          end
+        end
+
+        context 'with context' do
+          subject { described_class.new(index, to_index: to_index, delete: delete, fields: fields, context: {names: {42 => 'ContextName42'}}) }
+
+          specify do
+            expect(subject.bulk_body).to eq([
+              {index: {_id: 42, data: {'name' => 'ContextName42'}}}
+            ])
+          end
+        end
+      end
+    end
+
     context 'empty ids' do
       before do
         stub_index(:cities) do

spec/chewy/index/witchcraft_spec.rb

@@ -84,6 +84,19 @@ def self.mapping(&block)
       end
     end
 
+    context 'context' do
+      mapping do
+        field :name, value: ->(_o, _c, ctx) { ctx[:name] }
+      end
+
+      context do
+        let(:object) { double(name: 'Name') }
+        let(:crutches) { double }
+        let(:context) { {name: 'FromContext'} }
+        specify { expect(index.cauldron.brew(object, crutches, context)).to eq({name: 'FromContext'}.as_json) }
+      end
+    end
+
     context 'nesting' do
       context do
         mapping do