chore: improves logic within prerelease_deps session

Author: chalmerlowe

packages/google-cloud-spanner/noxfile.py

@@ -646,39 +646,36 @@ def prerelease_deps(session, protobuf_implementation, database_dialect):
     system_test_path = os.path.join("tests", "system.py")
     system_test_folder_path = os.path.join("tests", "system")
 
-    # Only run system tests for one protobuf implementation on real Spanner to speed up the build.
-    if os.environ.get("SPANNER_EMULATOR_HOST") or protobuf_implementation == "python":
-        # Sanity check: Only run system tests if credentials or emulator are set.
-        if os.environ.get("GOOGLE_APPLICATION_CREDENTIALS") or os.environ.get("SPANNER_EMULATOR_HOST"):
-            # Only run system tests if found.
-            if os.path.exists(system_test_path):
-                session.run(
-                    "py.test",
-                    "--verbose",
-                    f"--junitxml=system_{session.python}_sponge_log.xml",
-                    system_test_path,
-                    *session.posargs,
-                    env={
-                        "PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION": protobuf_implementation,
-                        "SPANNER_DATABASE_DIALECT": database_dialect,
-                        "SKIP_BACKUP_TESTS": "true",
-                    },
-                )
-            elif os.path.exists(system_test_folder_path):
-                session.run(
-                    "py.test",
-                    "--verbose",
-                    f"--junitxml=system_{session.python}_sponge_log.xml",
-                    system_test_folder_path,
-                    *session.posargs,
-                    env={
-                        "PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION": protobuf_implementation,
-                        "SPANNER_DATABASE_DIALECT": database_dialect,
-                        "SKIP_BACKUP_TESTS": "true",
-                    },
-                )
+    if os.environ.get("SPANNER_EMULATOR_HOST"):
+        # Run tests against the emulator
+        run_system = True
+    elif protobuf_implementation == "python":
+        # Run tests against real Spanner, but check creds first
+        if os.environ.get("GOOGLE_APPLICATION_CREDENTIALS"):
+            run_system = True
         else:
-            session.log("Skipping system tests because credentials/emulator are missing")
+            session.log("Skipping system tests because GOOGLE_APPLICATION_CREDENTIALS is not set")
+            run_system = False
+    else:
+        # Skip to speed up build (only run python implementation on real Spanner)
+        session.log(f"Skipping system tests for protobuf={protobuf_implementation} on real Spanner to speed up build")
+        run_system = False
+
+    if run_system:
+        # Run the tests (deduplicated logic)
+        test_path = system_test_path if os.path.exists(system_test_path) else system_test_folder_path
+        session.run(
+            "py.test",
+            "--verbose",
+            f"--junitxml=system_{session.python}_sponge_log.xml",
+            test_path,
+            *session.posargs,
+            env={
+                "PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION": protobuf_implementation,
+                "SPANNER_DATABASE_DIALECT": database_dialect,
+                "SKIP_BACKUP_TESTS": "true",
+            },
+        )
 
 @nox.session(python=DEFAULT_PYTHON_VERSION)
 def mypy(session):