Extend validation of finecode-user.toml

Author: Aksem

src/finecode/wm_server/config/read_configs.py

@@ -40,7 +40,8 @@ def read_project_user_config(project_dir: Path) -> dict | None:
     Returns the parsed mapping, or None if the file does not exist.
 
     Raises:
-        ConfigurationError: File is malformed or contains a [workspace] table.
+        ConfigurationError: File is malformed or contains a [workspace] or
+            [tool] table.
     """
     user_config_path = project_dir / "finecode-user.toml"
     if not user_config_path.exists():
@@ -58,6 +59,13 @@ def read_project_user_config(project_dir: Path) -> dict | None:
             f"{user_config_path}. "
             f"Workspace configuration must live in finecode-workspace.toml."
         )
+    if "tool" in raw:
+        raise config_models.ConfigurationError(
+            f"The [tool] table is not allowed in {user_config_path}. "
+            f"finecode-user.toml uses the same fields as finecode.toml but "
+            f"without the [tool.finecode] wrapper — write tables directly, "
+            f"e.g. [action.x] instead of [tool.finecode.action.x]."
+        )
     return raw
 
 
@@ -563,6 +571,13 @@ def read_preset_config(
             raise config_models.ConfigurationError(
                 f"The [workspace] table is not allowed in {preset_user_config_path}."
             )
+        if "tool" in preset_user_raw:
+            raise config_models.ConfigurationError(
+                f"The [tool] table is not allowed in {preset_user_config_path}. "
+                f"finecode-user.toml uses the same fields as preset.toml but "
+                f"without the [tool.finecode] wrapper — write tables directly, "
+                f"e.g. [action.x] instead of [tool.finecode.action.x]."
+            )
         if "dependency-groups" in preset_user_raw:
             logger.warning(
                 f"[dependency-groups] in {preset_user_config_path} is not supported "

tests/unit/test_read_configs.py

@@ -44,6 +44,23 @@ def test_project_user_config_workspace_table_raises(tmp_path: pathlib.Path) -> N
         read_project_user_config(tmp_path)
 
 
+def test_project_user_config_tool_table_raises(tmp_path: pathlib.Path) -> None:
+    """A [tool] table in finecode-user.toml is rejected with a clear error.
+
+    finecode-user.toml is unwrapped (no [tool.finecode] prefix); writing
+    [tool.finecode.action.x] instead of [action.x] used to reach
+    `_merge_projects_configs` and crash there with a bare `KeyError('tool')`
+    surfaced to the client as `API error (-32603): 'tool'`. Reject it eagerly
+    with an actionable message instead.
+    """
+    _write_toml(
+        tmp_path / "finecode-user.toml",
+        "[tool.finecode.action.lint]\nhandlers = []\n",
+    )
+    with pytest.raises(config_models.ConfigurationError, match=r"\[tool\]"):
+        read_project_user_config(tmp_path)
+
+
 def test_project_user_config_malformed_raises(tmp_path: pathlib.Path) -> None:
     """A parse error in finecode-user.toml is a hard failure.
 
@@ -846,3 +863,20 @@ def test_preset_user_config_workspace_table_raises(tmp_path: pathlib.Path) -> No
     _write_toml(tmp_path / "finecode-user.toml", "[workspace]\nfoo = 1\n")
     with pytest.raises(config_models.ConfigurationError, match="workspace"):
         read_preset_config(tmp_path / "preset.toml", "mypkg")
+
+
+def test_preset_user_config_tool_table_raises(tmp_path: pathlib.Path) -> None:
+    """A [tool] table in a preset-level finecode-user.toml is rejected.
+
+    Same double-wrapping bug as at the project level — a preset's
+    finecode-user.toml is unwrapped, so [tool.finecode.action.x] used to
+    reach `_merge_projects_configs` and crash with a bare `KeyError('tool')`
+    instead of an actionable error.
+    """
+    _write_minimal_preset(tmp_path)
+    _write_toml(
+        tmp_path / "finecode-user.toml",
+        "[tool.finecode.action.lint]\nhandlers = []\n",
+    )
+    with pytest.raises(config_models.ConfigurationError, match=r"\[tool\]"):
+        read_preset_config(tmp_path / "preset.toml", "mypkg")