RUBY-945 Add #database_names and #list_databases methods to Client and #list_collections method to Database

lib/mongo/client.rb

@@ -223,6 +223,32 @@ def write_concern
       @write_concern ||= WriteConcern.get(options[:write])
     end
 
+    # Get the names of all databases.
+    #
+    # @example Get the database names.
+    #   client.database_names
+    #
+    # @return [ Array<String> ] The names of the databases.
+    #
+    # @since 2.0.5
+    def database_names
+      list_databases.collect{ |info| info['name'] }
+    end
+
+    # Get info for each database.
+    #
+    # @example Get the info for each database.
+    #   client.list_databases
+    #
+    # @return [ Array<Hash> ] The info for each database.
+    #
+    # @since 2.0.5
+    def list_databases
+      use(Database::ADMIN).command(
+        listDatabases: 1
+      ).first['databases']
+    end
+
     private
 
     def create_from_addresses(addresses, opts = {})

lib/mongo/database.rb

@@ -102,6 +102,18 @@ def collection_names(options = {})
       View.new(self).collection_names(options)
     end
 
+    # Get info on all the collections in the database.
+    #
+    # @example Get info on each collection.
+    #   database.list_collections
+    #
+    # @return [ Array<Hash> ] Info for each collection in the database.
+    #
+    # @since 2.0.5
+    def list_collections
+      View.new(self).list_collections
+    end
+
     # Get all the collections that belong to this database.
     #
     # @example Get all the collections.

lib/mongo/database/view.rb

@@ -57,6 +57,18 @@ def collection_names(options = {})
         end
       end
 
+      # Get info on all the collections in the database.
+      #
+      # @example Get info on each collection.
+      #   database.list_collections
+      #
+      # @return [ Array<Hash> ] Info for each collection in the database.
+      #
+      # @since 2.0.5
+      def list_collections
+        collections_info(next_primary)
+      end
+
       # Create the new database view.
       #
       # @example Create the new database view.

spec/mongo/client_spec.rb

@@ -569,4 +569,23 @@
       end
     end
   end
+
+  describe '#database_names' do
+
+    it 'returns a list of database names' do
+      expect(root_authorized_client.database_names).to include(
+        'admin', 'local', TEST_DB
+      )
+    end
+  end
+
+  describe '#list_databases' do
+
+    it 'returns a list of database info documents' do
+      expect(
+        root_authorized_client.list_databases.collect do |i|
+          i['name']
+        end).to include('admin', 'local', TEST_DB)
+    end
+  end
 end

spec/mongo/database_spec.rb

@@ -95,6 +95,35 @@
     end
   end
 
+  describe '#list_collections' do
+
+    let(:database) do
+      described_class.new(authorized_client, TEST_DB)
+    end
+
+    let(:result) do
+      database.list_collections.map do |info|
+        info['name']
+      end
+    end
+
+    before do
+      database[:users].create
+    end
+
+    after do
+      database[:users].drop
+    end
+
+    it 'returns a list of the collections info', if: write_command_enabled?  do
+      expect(result).to include('users')
+    end
+
+    it 'returns a list of the collections info', unless: write_command_enabled?  do
+      expect(result).to include("#{TEST_DB}.users")
+    end
+  end
+
   describe '#collections' do
 
     context 'when the database exists' do

spec/support/authorization.rb

@@ -77,7 +77,8 @@
     Mongo::Auth::Roles::USER_ADMIN_ANY_DATABASE,
     Mongo::Auth::Roles::DATABASE_ADMIN_ANY_DATABASE,
     Mongo::Auth::Roles::READ_WRITE_ANY_DATABASE,
-    Mongo::Auth::Roles::HOST_MANAGER
+    Mongo::Auth::Roles::HOST_MANAGER,
+    Mongo::Auth::Roles::CLUSTER_ADMIN
   ]
 )
 
@@ -105,8 +106,8 @@
 # @since 2.0.
 TEST_READ_WRITE_USER = Mongo::Auth::User.new(
   database: TEST_DB,
-  user: 'test-user',
-  password: 'password',
+  user: TEST_USER.name,
+  password: TEST_USER.password,
   roles: [ Mongo::Auth::Roles::READ_WRITE, Mongo::Auth::Roles::DATABASE_ADMIN ]
 )