CXX-727 Add a name setter for renaming collections

Until now we had support for getting a collection's name by
using the getter collection::name(...); this overloads this
method with an additional name setter.

src/mongocxx/collection.cpp

@@ -65,6 +65,20 @@ stdx::string_view collection::name() const noexcept {
     return _impl->name;
 }
 
+void collection::rename(stdx::string_view new_name, bool drop_target_before_rename) {
+  bson_error_t error;
+
+  auto result = libmongoc::collection_rename(_impl->collection_t, _impl->database_name.c_str(),
+                                              new_name.data(), drop_target_before_rename, &error);
+
+  if (!result) {
+    throw exception::operation(std::make_tuple(error.message, error.code));
+  }
+
+  _impl->name = (std::string)new_name;
+}
+
+
 collection::collection(const database& database, stdx::string_view collection_name)
     : _impl(stdx::make_unique<impl>(
           libmongoc::database_get_collection(database._impl->database_t, collection_name.data()),

src/mongocxx/collection.hpp

@@ -476,6 +476,18 @@ class MONGOCXX_API collection {
     ///
     stdx::string_view name() const noexcept;
 
+    ///
+    /// Rename this collection.
+    ///
+    /// @param new_name The new name to assign to the collection.
+    /// @param drop_target_before_rename Whether to overwrite any
+    ///   existing collections called new_name. The default is false.
+    ///
+    /// @throws exception::operation if the operation fails.
+    ///
+    void rename(stdx::string_view new_name, bool drop_target_before_rename = false);
+
+
     ///
     /// Sets the read_preference for this collection. Changes will not have any effect on existing
     /// cursors or other read operations which use the read preference.

src/mongocxx/private/libmongoc_symbols.hpp

@@ -44,6 +44,7 @@ MONGOCXX_LIBMONGOC_SYMBOL(client_pool_try_pop)
 MONGOCXX_LIBMONGOC_SYMBOL(client_set_read_prefs)
 MONGOCXX_LIBMONGOC_SYMBOL(client_set_ssl_opts)
 MONGOCXX_LIBMONGOC_SYMBOL(client_set_write_concern)
+MONGOCXX_LIBMONGOC_SYMBOL(collection_rename)
 MONGOCXX_LIBMONGOC_SYMBOL(collection_aggregate)
 MONGOCXX_LIBMONGOC_SYMBOL(collection_count)
 MONGOCXX_LIBMONGOC_SYMBOL(collection_count_with_opts)

src/mongocxx/test/collection_mocked.cpp

@@ -466,4 +466,24 @@ TEST_CASE("Collection", "[collection]") {
         REQUIRE(bulk_operation_execute_called);
         REQUIRE(bulk_operation_destroy_called);
     }
+
+    SECTION("Rename Fails, name stays the same", "collection::rename") {
+      bool collection_rename_called  = false, collection_rename_error = false;
+      std::string old_name = (std::string)mongo_coll.name();
+
+      collection_rename->interpose([&](mongoc_collection_t *, const char*, const char*, bool, bson_error_t*) {
+        collection_rename_called = true;
+        return false;
+      });
+
+      try {
+        mongo_coll.rename("bad_name");
+      } catch (exception::operation &) {
+        collection_rename_error = true;
+      }
+
+      REQUIRE(collection_rename_called);
+      REQUIRE(collection_rename_error);
+      REQUIRE(mongocxx::stdx::string_view{old_name} == mongo_coll.name());
+    }
 }

src/third_party/catch/include/helpers.hpp

@@ -103,7 +103,8 @@
     auto collection_count_with_opts = libmongoc::collection_count_with_opts.create_instance();    \
     auto collection_create_index = libmongoc::collection_create_index.create_instance();          \
     auto collection_find = libmongoc::collection_find.create_instance();                          \
-    auto collection_aggregate = libmongoc::collection_aggregate.create_instance();
+    auto collection_aggregate = libmongoc::collection_aggregate.create_instance();                \
+    auto collection_rename = libmongoc::collection_rename.create_instance();
 
 #define MOCK_CURSOR                                                    \
     auto cursor_destroy = libmongoc::cursor_destroy.create_instance(); \