Fix:Error message for invalid task ID

Author: rahul-flex

Diff for: CHANGELOG.md

@@ -14,6 +14,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 - Compatibility with `xarray>=2025.03`.
 
+### Changed
+- Error message for invalid task ID.
+
 ## [2.8.1] - 2025-03-20
 
 ### Added

Diff for: tests/test_web/test_webapi.py

@@ -39,6 +39,7 @@
     upload,
 )
 from tidy3d.web.core.environment import Env
+from tidy3d.web.core.exceptions import TaskNotFoundError
 from tidy3d.web.core.types import TaskType
 
 TASK_NAME = "task_name_test"
@@ -722,3 +723,18 @@ def save_sim_to_path(path: str) -> None:
                 "--inspect_sim",
             ]
         )
+
+
+@responses.activate
+def test_load_invalid_task_raises(mock_webapi):
+    """Ensure that load() raises TaskNotFoundError for a non-existent task ID."""
+    fake_id = "INVALID_TASK_ID"
+
+    responses.add(
+        responses.GET,
+        f"{Env.current.web_api_endpoint}/tidy3d/tasks/{fake_id}/detail",
+        json={"error": "Task not found"},
+        status=404,
+    )
+    with pytest.raises(TaskNotFoundError, match="does not exist"):
+        load(fake_id)

Diff for: tidy3d/web/core/exceptions.py

@@ -11,3 +11,15 @@ def __init__(self, message: str = None):
         log = get_logger()
         super().__init__(message)
         log.error(message)
+
+
+class TaskNotFoundError(WebError):
+    """Raised when a requested task ID does not exist on the server."""
+
+    pass
+
+
+class WebNotFoundError(WebError):
+    """A generic error indicating an HTTP 404 (resource not found)."""
+
+    pass

Diff for: tidy3d/web/core/http_util.py

@@ -25,7 +25,7 @@
 )
 from .core_config import get_logger
 from .environment import Env
-from .exceptions import WebError
+from .exceptions import WebError, WebNotFoundError
 
 REINITIALIZED = False
 
@@ -131,7 +131,7 @@ def wrapper(*args, **kwargs):
 
         if resp.status_code != ResponseCodes.OK.value:
             if resp.status_code == ResponseCodes.NOT_FOUND.value:
-                return None
+                raise WebNotFoundError("Resource not found (HTTP 404).")
             json_resp = resp.json()
             if "error" in json_resp.keys():
                 raise WebError(json_resp["error"])

Diff for: tidy3d/web/core/task_core.py

@@ -17,7 +17,7 @@
 from .constants import SIM_ERROR_FILE, SIM_FILE_HDF5_GZ, SIM_LOG_FILE, SIMULATION_DATA_HDF5_GZ
 from .core_config import get_logger_console
 from .environment import Env
-from .exceptions import WebError
+from .exceptions import TaskNotFoundError, WebError, WebNotFoundError
 from .file_util import read_simulation_from_hdf5
 from .http_util import http
 from .s3utils import download_file, download_gz_file, upload_file
@@ -261,7 +261,10 @@ def get(cls, task_id: str, verbose: bool = True) -> SimulationTask:
             :class:`.SimulationTask` object containing info about status,
              size, credits of task and others.
         """
-        resp = http.get(f"tidy3d/tasks/{task_id}/detail")
+        try:
+            resp = http.get(f"tidy3d/tasks/{task_id}/detail")
+        except WebNotFoundError:
+            raise TaskNotFoundError(f"The requested task ID '{task_id}' does not exist.")
         task = SimulationTask(**resp) if resp else None
         return task