refactor: improve type safety and error handling

- Add explicit variable initializations to avoid unbound errors.
- Add runtime checks and raise exceptions for unexpected None values.
- Refactor conditional logic for clarity and correctness.
- Add missing assertions and error messages for better diagnostics.
- Add pyright ignore comments for type checking compatibility.
- Improve error handling in dbsync queries and utility functions.
- Remove unnecessary comments and update ignore directives.
- No breaking changes to public APIs.

These changes improve static analysis compatibility (e.g., pyright) and
make error handling more robust throughout the codebase.

Author: mkoura

cardano_node_tests/cardano_cli_coverage.py

@@ -57,7 +57,7 @@
 
 def get_args() -> argparse.Namespace:
     """Get script command line arguments."""
-    parser = argparse.ArgumentParser(description=__doc__.split("\n", maxsplit=1)[0])
+    parser = argparse.ArgumentParser(description=(__doc__ or "").split("\n", maxsplit=1)[0])
     parser.add_argument(
         "-i",
         "--input-files",

cardano_node_tests/chang_us_coverage.py

@@ -14,7 +14,7 @@
 
 def get_args() -> argparse.Namespace:
     """Get command line arguments."""
-    parser = argparse.ArgumentParser(description=__doc__.split("\n", maxsplit=1)[0])
+    parser = argparse.ArgumentParser(description=(__doc__ or "").split("\n", maxsplit=1)[0])
     parser.add_argument(
         "-i",
         "--input-file",

cardano_node_tests/cluster_management/cluster_getter.py

@@ -33,9 +33,7 @@
     _xdist_sleep = time.sleep
 else:
 
-    def _xdist_sleep(
-        secs: float,
-    ) -> None:
+    def _xdist_sleep(seconds: float, /) -> None:
         """No need to sleep if tests are running on a single worker."""
 
 
@@ -167,6 +165,7 @@ def _netstat_log_func(msg: str) -> None:
         excp: Exception | None = None
         netstat_out = ""
         ports = self.ports
+        cluster_obj = None
         for i in range(2):
             if i > 0:
                 self.log(
@@ -234,6 +233,11 @@ def _netstat_log_func(msg: str) -> None:
             status_files.create_cluster_dead_file(instance_num=self.cluster_instance_num)
             return False
 
+        if cluster_obj is None:
+            # Should never reach this
+            self.log(f"c{self.cluster_instance_num}: failed to start cluster")
+            return False
+
         # Generate ID for the new cluster instance so it is possible to match log entries with
         # cluster instance files saved as artifacts.
         cluster_instance_id = helpers.get_rand_str(8)

cardano_node_tests/defragment_utxos.py

@@ -17,7 +17,7 @@
 
 def get_args() -> argparse.Namespace:
     """Get command line arguments."""
-    parser = argparse.ArgumentParser(description=__doc__.split("\n", maxsplit=1)[0])
+    parser = argparse.ArgumentParser(description=(__doc__ or "").split("\n", maxsplit=1)[0])
     parser.add_argument(
         "-a",
         "--address",

cardano_node_tests/dump_requirements_coverage.py

@@ -14,7 +14,7 @@
 
 def get_args() -> argparse.Namespace:
     """Get command line arguments."""
-    parser = argparse.ArgumentParser(description=__doc__.split("\n", maxsplit=1)[0])
+    parser = argparse.ArgumentParser(description=(__doc__ or "").split("\n", maxsplit=1)[0])
     parser.add_argument(
         "-m",
         "--requirements-mapping",

cardano_node_tests/prepare_cluster_scripts.py

@@ -21,7 +21,7 @@
 
 def get_args() -> argparse.Namespace:
     """Get command line arguments."""
-    parser = argparse.ArgumentParser(description=__doc__.split("\n", maxsplit=1)[0])
+    parser = argparse.ArgumentParser(description=(__doc__ or "").split("\n", maxsplit=1)[0])
     parser.add_argument(
         "-d",
         "--dest-dir",

cardano_node_tests/pytest_plugins/xdist_scheduler.py

@@ -67,7 +67,7 @@ def _split_scope(self, nodeid: str) -> str:
 
         return comps[1]  # nodeid has a group name
 
-    def _is_long_pending(self, assigned_to_node: collections.OrderedDict) -> bool:
+    def _is_long_pending(self, assigned_to_node: dict) -> bool:
         """Return True if there is a long-running test pending."""
         for nodeids_dict in assigned_to_node.values():
             for nodeid, is_completed in nodeids_dict.items():
@@ -104,7 +104,7 @@ def _assign_work_unit(self, node: workermanage.WorkerController) -> None:
         scope, work_unit = None, None
 
         # Check if there are any long-running tests already pending
-        # pyrefly: ignore  # bad-argument-type
+
         long_pending = self._is_long_pending(assigned_to_node)
 
         if long_pending:

cardano_node_tests/split_topology.py

@@ -16,7 +16,7 @@
 
 def get_args() -> argparse.Namespace:
     """Get command line arguments."""
-    parser = argparse.ArgumentParser(description=__doc__.split("\n", maxsplit=1)[0])
+    parser = argparse.ArgumentParser(description=(__doc__ or "").split("\n", maxsplit=1)[0])
     parser.add_argument(
         "-d",
         "--dest-dir",

cardano_node_tests/testnet_cleanup.py

@@ -23,7 +23,7 @@
 
 def get_args() -> argparse.Namespace:
     """Get command line arguments."""
-    parser = argparse.ArgumentParser(description=__doc__.split("\n", maxsplit=1)[0])
+    parser = argparse.ArgumentParser(description=(__doc__ or "").split("\n", maxsplit=1)[0])
     parser.add_argument(
         "-a",
         "--artifacts-base-dir",

cardano_node_tests/testnet_cleanup_info.py

@@ -17,7 +17,7 @@
 
 def get_args() -> argparse.Namespace:
     """Get command line arguments."""
-    parser = argparse.ArgumentParser(description=__doc__.split("\n", maxsplit=1)[0])
+    parser = argparse.ArgumentParser(description=(__doc__ or "").split("\n", maxsplit=1)[0])
     parser.add_argument(
         "-a",
         "--artifacts-base-dir",