From 7bec7dc38d6f076523652d99f641467970ac6cca Mon Sep 17 00:00:00 2001
From: stacknil <stacknil@proton.me>
Date: Fri, 15 May 2026 18:04:44 +0800
Subject: [PATCH] Improve CLI error reporting

---
 src/telemetry_window_demo/cli.py | 11 ++++---
 src/telemetry_window_demo/io.py  | 19 +++++++-----
 tests/test_cli_errors.py         | 50 ++++++++++++++++++++++++++++++++
 3 files changed, 69 insertions(+), 11 deletions(-)
 create mode 100644 tests/test_cli_errors.py

diff --git a/src/telemetry_window_demo/cli.py b/src/telemetry_window_demo/cli.py
index 6b4f2cc..e66c218 100644
--- a/src/telemetry_window_demo/cli.py
+++ b/src/telemetry_window_demo/cli.py
@@ -42,10 +42,13 @@
 }
 
 
-def main() -> None:
-    parser = build_parser()
-    args = parser.parse_args()
-    args.func(args)
+def main(argv: Sequence[str] | None = None) -> None:
+    parser = build_parser()
+    args = parser.parse_args(argv)
+    try:
+        args.func(args)
+    except (OSError, ValueError) as exc:
+        parser.exit(status=1, message=f"error: {exc}\n")
 
 
 def build_parser() -> argparse.ArgumentParser:
diff --git a/src/telemetry_window_demo/io.py b/src/telemetry_window_demo/io.py
index a04647d..377482f 100644
--- a/src/telemetry_window_demo/io.py
+++ b/src/telemetry_window_demo/io.py
@@ -10,13 +10,18 @@
 from .schema import validate_event_frame
 
 
-def load_config(path: str | Path) -> dict[str, Any]:
-    config_path = Path(path)
-    with config_path.open("r", encoding="utf-8") as handle:
-        config = yaml.safe_load(handle) or {}
-    if not isinstance(config, dict):
-        raise ValueError("Configuration must deserialize to a mapping.")
-    return config
+def load_config(path: str | Path) -> dict[str, Any]:
+    config_path = Path(path)
+    if not config_path.exists():
+        raise FileNotFoundError(f"Config file not found: {config_path}")
+    try:
+        with config_path.open("r", encoding="utf-8") as handle:
+            config = yaml.safe_load(handle) or {}
+    except yaml.YAMLError as exc:
+        raise ValueError(f"Invalid YAML config in {config_path}: {exc}") from exc
+    if not isinstance(config, dict):
+        raise ValueError("Configuration must deserialize to a mapping.")
+    return config
 
 
 def resolve_config_path(config_path: str | Path, value: str | Path) -> Path:
diff --git a/tests/test_cli_errors.py b/tests/test_cli_errors.py
new file mode 100644
index 0000000..5699af7
--- /dev/null
+++ b/tests/test_cli_errors.py
@@ -0,0 +1,50 @@
+from __future__ import annotations
+
+import pytest
+import yaml
+
+from telemetry_window_demo.cli import main
+
+
+def test_main_reports_config_errors_without_traceback(tmp_path, capsys) -> None:
+    config_path = tmp_path / "missing-input-path.yaml"
+    config_path.write_text(
+        yaml.safe_dump({"output_dir": str(tmp_path / "processed")}),
+        encoding="utf-8",
+    )
+
+    with pytest.raises(SystemExit) as excinfo:
+        main(["run", "--config", str(config_path)])
+
+    assert excinfo.value.code == 1
+    stderr = capsys.readouterr().err
+    assert stderr.startswith("error: ")
+    assert "input_path" in stderr
+    assert "Traceback" not in stderr
+
+
+def test_main_reports_missing_config_without_traceback(tmp_path, capsys) -> None:
+    config_path = tmp_path / "missing.yaml"
+
+    with pytest.raises(SystemExit) as excinfo:
+        main(["run", "--config", str(config_path)])
+
+    assert excinfo.value.code == 1
+    stderr = capsys.readouterr().err
+    assert stderr.startswith("error: ")
+    assert "Config file not found" in stderr
+    assert "Traceback" not in stderr
+
+
+def test_main_reports_invalid_yaml_config_without_traceback(tmp_path, capsys) -> None:
+    config_path = tmp_path / "broken.yaml"
+    config_path.write_text("input_path: [\n", encoding="utf-8")
+
+    with pytest.raises(SystemExit) as excinfo:
+        main(["run", "--config", str(config_path)])
+
+    assert excinfo.value.code == 1
+    stderr = capsys.readouterr().err
+    assert stderr.startswith("error: ")
+    assert "Invalid YAML config" in stderr
+    assert "Traceback" not in stderr