Fix the order of checks for in-memory duckdb option

dlt/destinations/impl/duckdb/configuration.py

@@ -119,9 +119,6 @@ def is_partial(self) -> bool:
         return self.database == ":pipeline:"
 
     def on_resolved(self) -> None:
-        if isinstance(self.database, str) and self.database == ":memory:":
-            raise InvalidInMemoryDuckdbCredentials()
-
         # do not set any paths for external database
         if self.database == ":external:":
             return
@@ -138,6 +135,12 @@ def on_resolved(self) -> None:
                 is_default_path = maybe_is_default_path
                 self.database = maybe_database
 
+        # We need to check it here because the default `native_value` for duckdb is :memory:
+        # thus if we do this check at the very beginning we will fail the default usecase
+        # when users just specify destination="duckdb" thus it is undesired behavior.
+        if isinstance(self.database, str) and self.database == ":memory:":
+            raise InvalidInMemoryDuckdbCredentials()
+
         # always make database an abs path
         self.database = os.path.abspath(self.database)
         # do not save the default path into pipeline's local state

tests/load/duckdb/test_duckdb_client.py

@@ -64,7 +64,11 @@ def test_duckdb_in_memory_mode_via_factory(preserve_environ):
 
         # Check if passing external duckdb connection works fine
         db = duckdb.connect(":memory:")
-        dlt.pipeline(pipeline_name="booboo", destination=dlt.destinations.duckdb(db))
+        p = dlt.pipeline(pipeline_name="booboo", destination=dlt.destinations.duckdb(db))
+        p.run()
+
+        p = dlt.pipeline(pipeline_name="normal-pipeline-with-duckdb", destination="duckdb")
+        p.run()
 
         # Check if passing :memory: to factory fails
         with pytest.raises(PipelineStepFailed) as exc: