SNOW-2306184: config refactor - connections toml merging split

Author: sfc-gh-mraba

src/snowflake/cli/api/config_provider.py

@@ -448,9 +448,17 @@ def _get_connection_dict_internal(self, connection_name: str) -> Dict[str, Any]:
                 param_names.add(param_name)
 
         # Get param names from flat keys (general env vars, SnowSQL env, CLI params)
-        # Skip internal CLI arguments that aren't connection parameters
+        # Skip internal CLI arguments and global settings that aren't connection parameters
         for key in self._config_cache.keys():
-            if "." not in key and key not in ("enable_diag", "temporary_connection"):
+            if "." not in key and key not in (
+                "enable_diag",
+                "temporary_connection",
+                "default_connection_name",
+                "connection_name",
+                "diag_log_path",
+                "diag_allowlist_path",
+                "mfa_passcode",
+            ):
                 param_names.add(key)
 
         # For each parameter, determine the best value based on source priority

tests/test_config.py

@@ -34,6 +34,11 @@
 from tests_common import IS_WINDOWS
 
 
+def is_config_ng_enabled():
+    """Check if config_ng is enabled via environment variable"""
+    return os.getenv("SNOWFLAKE_CLI_CONFIG_V2_ENABLED") == "true"
+
+
 def test_empty_config_file_is_created_if_not_present():
     from snowflake.cli.api.utils.path_utils import path_resolver
 
@@ -383,7 +388,12 @@ def assert_correct_connections_loaded():
         assert_correct_connections_loaded()
 
 
-def test_connections_toml_override_config_toml(
+# Legacy version - skip when config_ng is enabled
+@pytest.mark.skipif(
+    is_config_ng_enabled(),
+    reason="Legacy behavior: connections.toml replaces all connections from config.toml",
+)
+def test_connections_toml_override_config_toml_legacy(
     test_snowcli_config, snowflake_home, config_manager
 ):
     connections_toml = snowflake_home / "connections.toml"
@@ -394,12 +404,49 @@ def test_connections_toml_override_config_toml(
     )
     config_init(test_snowcli_config)
 
+    # Legacy: Only connections from connections.toml are present
     assert get_default_connection_dict() == {"database": "overridden_database"}
     assert config_manager["connections"] == {
         "default": {"database": "overridden_database"}
     }
 
 
+# Config_ng version - skip when config_ng is NOT enabled
+@pytest.mark.skipif(
+    not is_config_ng_enabled(),
+    reason="Config_ng behavior: connections.toml merges with config.toml per-key",
+)
+def test_connections_toml_override_config_toml_config_ng(
+    test_snowcli_config, snowflake_home, config_manager
+):
+    """Test config_ng behavior: connections.toml merges with config.toml per-key"""
+    connections_toml = snowflake_home / "connections.toml"
+    connections_toml.write_text(
+        """[default]
+    database = "overridden_database"
+    """
+    )
+    config_init(test_snowcli_config)
+
+    # Config_ng: Merged - database from connections.toml, other keys from config.toml
+    # The key difference from legacy: keys from config.toml are preserved
+    default_conn = get_default_connection_dict()
+
+    # Key from connections.toml (level 3) overrides
+    assert default_conn["database"] == "overridden_database"
+
+    # Keys from config.toml (level 2) are preserved
+    assert default_conn["schema"] == "test_public"
+    assert default_conn["role"] == "test_role"
+    assert default_conn["warehouse"] == "xs"
+    assert default_conn["password"] == "dummy_password"
+
+    # Verify other connections from config.toml are also accessible
+    full_conn = get_connection_dict("full")
+    assert full_conn["account"] == "dev_account"
+    assert full_conn["user"] == "dev_user"
+
+
 parametrize_chmod = pytest.mark.parametrize(
     "chmod",
     [