Do not raise an error if a non-existent collection is dropped

Author: estolfo

lib/mongo/collection.rb

@@ -84,6 +84,8 @@ def create
     # Drop the collection. Will also drop all indexes associated with the
     # collection.
     #
+    # @note An error returned if the collection doesn't exist is suppressed.
+    #
     # @example Drop the collection.
     #   collection.drop
     #
@@ -92,6 +94,9 @@ def create
     # @since 2.0.0
     def drop
       database.command(:drop => name)
+    rescue Error::OperationFailure => ex
+      raise ex unless ex.message =~ /ns not found/
+      false
     end
 
     # Find documents in the collection.

spec/mongo/collection_spec.rb

@@ -229,6 +229,13 @@
     it 'drops the collection from the database' do
       expect(database.collection_names).to_not include('specs')
     end
+
+    context 'when the collection does not exist' do
+
+      it 'does not raise an error' do
+        expect(database['non-existent-coll'].drop).to be(false)
+      end
+    end
   end
 
   describe '#find' do