Add Mongo::Client#collections spec

Author: namusyaka

spec/mongo/client_spec.rb

@@ -742,4 +742,28 @@
       expect(client.dup.options).to be_a(Mongo::Options::Redacted)
     end
   end
+
+  describe '#collections' do
+
+    let(:client) do
+      described_class.new(['127.0.0.1:27017'], :database => TEST_DB)
+    end
+
+    before do
+      client.database[:users].create
+    end
+
+    after do
+      client.database[:users].drop
+    end
+
+    let(:collection) do
+      Mongo::Collection.new(client.database, 'users')
+    end
+
+    it 'refers the current database collections' do
+      expect(client.collections).to include(collection)
+      expect(client.collections).to all(be_a(Mongo::Collection))
+    end
+  end
 end