CXX-802 - coll.drop() no longer throws if collection doesn't exist

Author: Tess Avitabile

examples/mongocxx/bulk_write.cpp

@@ -29,15 +29,8 @@ using bsoncxx::builder::stream::open_document;
 int main(int, char**) {
     mongocxx::instance inst{};
     mongocxx::client conn{mongocxx::uri{}};
-
-    auto db = conn["test"];
-
-    // Ensure collection is empty.
-    if (db.has_collection("coll")) {
-        db["coll"].drop();
-    }
-
-    auto coll = db["coll"];
+    auto coll = conn["test"]["coll"];
+    coll.drop();
 
     // @begin: cpp-bulk-write
     auto doc1 = document{} << "a" << 1 << finalize;

src/mongocxx/collection.cpp

@@ -735,7 +735,7 @@ void collection::drop() {
 
     auto result = libmongoc::collection_drop(_get_impl().collection_t, &error);
 
-    if (!result) {
+    if (!result && (error.code != ::MONGOC_ERROR_COLLECTION_DOES_NOT_EXIST)) {
         throw_exception<operation_exception>(error);
     }
 }

src/mongocxx/exception/private/error_category.cpp

@@ -252,6 +252,8 @@ class mongoc_query_error_category final : public std::error_category {
                 return "mongoc query_failure error";
             case ::MONGOC_ERROR_QUERY_NOT_TAILABLE:
                 return "mongoc query_not_tailable error";
+            case ::MONGOC_ERROR_COLLECTION_DOES_NOT_EXIST:
+                return "mongoc collection_does_not_exist error";
             default:
                 return "unknown mongoc query error";
         }

src/mongocxx/test/collection.cpp

@@ -73,7 +73,7 @@ TEST_CASE("CRUD functionality", "[driver::collection]") {
     database db = mongodb_client["test"];
     collection coll = db["mongo_cxx_driver"];
 
-    if (db.has_collection("mongo_cxx_driver")) coll.drop();
+    coll.drop();
 
     SECTION("insert and read single document", "[collection]") {
         auto b = document{} << "_id" << bsoncxx::oid{bsoncxx::oid::init_tag} << "x" << 1
@@ -526,9 +526,8 @@ TEST_CASE("CRUD functionality", "[driver::collection]") {
     SECTION("distinct works", "[collection]") {
         auto distinct_cname = "distinct_coll";
         auto distinct_coll = db[distinct_cname];
-        if (db.has_collection(distinct_cname)) {
-            distinct_coll.drop();
-        }
+        distinct_coll.drop();
+        
         auto doc1 = document{} << "foo"
                                << "baz"
                                << "garply" << 1 << finalize;

src/mongocxx/test/database.cpp

@@ -32,17 +32,6 @@ using bsoncxx::builder::stream::document;
 using bsoncxx::builder::stream::finalize;
 using bsoncxx::builder::stream::open_document;
 
-namespace {
-
-// Clean up the given collection if it exists
-void clear_collection(const database& database, bsoncxx::stdx::string_view collection_name) {
-    if (database.has_collection(collection_name)) {
-        database[collection_name].drop();
-    }
-}
-
-}  // namespace
-
 TEST_CASE("A default constructed database is false-ish", "[database]") {
     database d;
     REQUIRE(!d);
@@ -269,14 +258,14 @@ TEST_CASE("Database integration tests", "[database]") {
 
     SECTION("A database may create a collection via create_collection") {
         SECTION("without any options") {
-            clear_collection(database, collection_name);
+            database[collection_name].drop();
 
             collection obtained_collection = database.create_collection(collection_name);
             REQUIRE(obtained_collection.name() == collection_name);
         }
 
         SECTION("with options") {
-            clear_collection(database, collection_name);
+            database[collection_name].drop();
 
             options::create_collection opts;
             opts.capped(true);
@@ -289,14 +278,14 @@ TEST_CASE("Database integration tests", "[database]") {
         }
 
         SECTION("but raises exception when collection already exists") {
-            clear_collection(database, collection_name);
+            database[collection_name].drop();
 
             database.create_collection(collection_name);
 
             REQUIRE_THROWS(database.create_collection(collection_name));
         }
 
-        clear_collection(database, collection_name);
+        database[collection_name].drop();
     }
 
     SECTION("A collection may be modified via modify_collection") {
@@ -322,7 +311,7 @@ TEST_CASE("Database integration tests", "[database]") {
     }
 
     SECTION("A database may be dropped") {
-        clear_collection(database, collection_name);
+        database[collection_name].drop();
 
         database.create_collection(collection_name);
         REQUIRE(database.has_collection(collection_name));