RUBY-1592 Add tests for connecting to all topologies in all possible ways (#1168)

Author: p-mongo

spec/integration/client_connectivity_spec.rb

@@ -1,5 +1,8 @@
 require 'spec_helper'
 
+# This test is for checking connectivity of the test client to the
+# test cluster. In other words, it is a test that the test suite is
+# configured correctly.
 describe 'Client connectivity' do
   shared_examples_for 'is correctly configured' do
     it 'is configured with the correct database' do

spec/integration/client_construction_spec.rb

@@ -0,0 +1,94 @@
+require 'spec_helper'
+
+# Create a client with all possible configurations (forcing/discovering each
+# topology type) and ensure the resulting client is usable.
+describe 'Client construction' do
+  let(:base_options) do
+    SpecConfig.instance.test_options.merge(
+      database: SpecConfig.instance.test_db,
+      user: SpecConfig.instance.test_user.name,
+      password: SpecConfig.instance.test_user.password)
+  end
+
+  context 'in single topology' do
+    require_topology :single
+
+    it 'discovers standalone' do
+      options = base_options.dup
+      options.delete(:connect)
+      client = ClientRegistry.instance.new_local_client([SpecConfig.instance.addresses.first],
+        options)
+      client['client_construction'].insert_one(test: 1)
+      expect(client.cluster.topology).to be_a(Mongo::Cluster::Topology::Single)
+      expect(client.options[:connect]).to be nil
+    end
+
+    it 'connects directly' do
+      client = ClientRegistry.instance.new_local_client([SpecConfig.instance.addresses.first],
+        base_options.merge(connect: :direct))
+      client['client_construction'].insert_one(test: 1)
+      expect(client.cluster.topology).to be_a(Mongo::Cluster::Topology::Single)
+      expect(client.options[:connect]).to eq :direct
+    end
+  end
+
+  context 'in replica set topology' do
+    require_topology :replica_set
+
+    it 'discovers replica set' do
+      options = base_options.dup
+      options.delete(:connect)
+      options.delete(:replica_set)
+      client = ClientRegistry.instance.new_local_client([SpecConfig.instance.addresses.first],
+        options)
+      client['client_construction'].insert_one(test: 1)
+      expect(client.cluster.topology).to be_a(Mongo::Cluster::Topology::ReplicaSetWithPrimary)
+      expect(client.options[:connect]).to be nil
+      expect(client.options[:replica_set]).to be nil
+    end
+
+    it 'forces replica set' do
+      replica_set_name = ClusterConfig.instance.replica_set_name
+      expect(replica_set_name).not_to be nil
+      client = ClientRegistry.instance.new_local_client([SpecConfig.instance.addresses.first],
+        base_options.merge(connect: :replica_set,
+          replica_set: replica_set_name))
+      client['client_construction'].insert_one(test: 1)
+      expect(client.cluster.topology).to be_a(Mongo::Cluster::Topology::ReplicaSetWithPrimary)
+      expect(client.options[:connect]).to be :replica_set
+      expect(client.options[:replica_set]).to eq(replica_set_name)
+    end
+
+    it 'connects directly' do
+      primary_address = ClusterConfig.instance.primary_address
+      client = ClientRegistry.instance.new_local_client([primary_address],
+        base_options.merge(connect: :direct))
+      client['client_construction'].insert_one(test: 1)
+      expect(client.cluster.topology).to be_a(Mongo::Cluster::Topology::Single)
+      expect(client.options[:connect]).to eq :direct
+    end
+  end
+
+  context 'in sharded topology' do
+    require_topology :sharded
+
+    it 'connects to sharded cluster' do
+      options = base_options.dup
+      options.delete(:connect)
+      client = ClientRegistry.instance.new_local_client([SpecConfig.instance.addresses.first],
+        base_options.merge(connect: :sharded))
+      client['client_construction'].insert_one(test: 1)
+      expect(client.cluster.topology).to be_a(Mongo::Cluster::Topology::Sharded)
+      expect(client.options[:connect]).to be :sharded
+    end
+
+    it 'connects directly' do
+      primary_address = ClusterConfig.instance.primary_address
+      client = ClientRegistry.instance.new_local_client([SpecConfig.instance.addresses.first],
+        base_options.merge(connect: :direct))
+      client['client_construction'].insert_one(test: 1)
+      expect(client.cluster.topology).to be_a(Mongo::Cluster::Topology::Single)
+      expect(client.options[:connect]).to eq :direct
+    end
+  end
+end