fix: [SNOW-3480430] actionable error when a [connections] entry is not a table

RELEASE-NOTES.md

@@ -26,6 +26,7 @@
 * Fixed `SELECT *` output being corrupted when joined tables share column names. Duplicate column names are now disambiguated by appending a numeric suffix (e.g. `NAME`, `NAME_2`).
 * Fixed `snow connection generate-jwt` and `snow connection generate-workload-identity-token` failing with `Connection None is not configured` when used with `--temporary-connection`.
 * The internal connection cache now remembers failed connect attempts and re-raises the original exception on subsequent accesses within the same process, instead of re-dialing Snowflake every time a command accesses the shared connection. This fixes, among other cases, the customer-visible duplicate `LOGIN_HISTORY` events (and `OVERFLOW_FAILURE_EVENTS_ELIDED`) previously emitted when a `snow` invocation was rejected by an authentication policy.
+* `snow connection list` (and other commands that enumerate connections) now raises a clear, actionable error when the `[connections]` section of `config.toml` contains an entry that is not a table (for example, a stray `default = "something"` line at the top of the section). Previously these configurations produced an unhandled `AttributeError: 'String' object has no attribute 'items'` with no indication of which entry was wrong.
 
 
 # v3.17.0

src/snowflake/cli/api/config_provider.py

@@ -136,14 +136,21 @@ def get_connection_dict(self, connection_name: str) -> dict:
             )
 
     def get_all_connections(self, include_env_connections: bool = False) -> dict:
+        from click import ClickException
         from snowflake.cli.api.config import ConnectionConfig, get_config_section
 
         # Legacy provider ignores the flag since it never had env connections
         connections = get_config_section("connections")
-        return {
-            name: ConnectionConfig.from_dict(config)
-            for name, config in connections.items()
-        }
+        result = {}
+        for name, config in connections.items():
+            if not isinstance(config, dict):
+                raise ClickException(
+                    f"Connection '{name}' in the configuration file is malformed: "
+                    f"expected a table of connection parameters but found a {type(config).__name__}. "
+                    f"Each connection must be defined as [connections.{name}] with key = value entries."
+                )
+            result[name] = ConnectionConfig.from_dict(config)
+        return result
 
 
 class AlternativeConfigProvider(ConfigProvider):

tests/test_connection.py

@@ -415,6 +415,32 @@ def test_mask_sensitive_parameters_masks_all_known_sensitive_keys():
     assert params["password"] == "hunter2"
 
 
+@mock.patch.dict(os.environ, {}, clear=True)
+def test_connection_list_reports_malformed_connection_entry(runner):
+    with NamedTemporaryFile("w+", suffix=".toml") as tmp_file:
+        tmp_file.write(
+            dedent(
+                """\
+                [connections]
+                default = "conn"
+
+                [connections.conn]
+                user = "foo"
+                """
+            )
+        )
+        tmp_file.flush()
+        os.chmod(tmp_file.name, 0o600)
+        result = runner.invoke_with_config_file(
+            tmp_file.name, ["connection", "list", "--format", "json"]
+        )
+
+    assert result.exit_code != 0, result.output
+    assert "malformed" in result.output
+    assert "default" in result.output
+    assert "[connections.default]" in result.output
+
+
 @mock.patch.dict(
     os.environ,
     {