MONGOID-5388 - Add Index wildcard_projection option and test for wildcard index (#5328)

* Add Index wildcard_projection option and test for wildcard index

* Update lib/mongoid/indexable/validators/options.rb

* Remove unneeded specs

Co-authored-by: shields <[email protected]>
Co-authored-by: Oleg Pudeyev <[email protected]>

Author: johnnyshields

lib/config/locales/en.yml

@@ -238,6 +238,7 @@ en:
             \_\_language_override\n
             \_\_default_language\n
             \_\_collation\n
+            \_\_wildcard_projection: { 'path.to.field.a': 1, 'path.to.field.b': 0 }\n
             Valid types are: 1, -1, '2d', '2dsphere', 'geoHaystack (deprecated)', 'text', 'hashed'\n\n
             Example:\n
             \_\_class Band\n

lib/mongoid/indexable/validators/options.rb

@@ -28,7 +28,8 @@ module Options
           :text_version,
           :version,
           :partial_filter_expression,
-          :collation
+          :collation,
+          :wildcard_projection,
         ]
 
         VALID_TYPES = [

spec/mongoid/indexable_spec.rb

@@ -223,8 +223,11 @@ def self.hereditary?
     let(:klass) do
       Class.new do
         include Mongoid::Document
-        field :a, as: :authentication_token
+
         store_in collection: :specs
+
+        field :a, as: :authentication_token
+        field :username
       end
     end
 
@@ -588,6 +591,25 @@ def self.hereditary?
       end
     end
 
+    context "when using a wildcard index" do
+
+      before do
+        klass.index({ '$**': 1 }, wildcard_projection: { _id: 1, username: 0 })
+      end
+
+      let(:spec) do
+        klass.index_specification('$**': 1)
+      end
+
+      it "creates the index" do
+        expect(spec).to be_a(Mongoid::Indexable::Specification)
+      end
+
+      it "sets the index with correct options" do
+        expect(spec.options).to eq(wildcard_projection: { _id: 1, username: 0 })
+      end
+    end
+
     context "when providing an invalid option" do
 
       it "raises an error" do