fix: return 400 on duplicate logger name in PUT /api/logger/:id

CHANGELOG.md

@@ -20,6 +20,7 @@ When adding a new entry, please use the following format:
 
 - [2026-03-30] fix: added test decorators to resolve lack of "TTN_API_KEY" on fork PR's. removed k6 from github actions. changed github action to utilize env-import.py as opposeed to directly accessing s3 bucket for env variables. [#736] (https://github.com/jlab-sensing/ENTS-backend/pull/736)
 - [2026-03-23] fix: increase fallback SECRET_KEY length to resolve PyJWT InsecureKeyLengthWarning [#682](https://github.com/jlab-sensing/ENTS-backend/pull/682)
+- [2026-03-21] fix: Return 400 on duplicate logger name in PUT /api/logger/:id [#710](https://github.com/jlab-sensing/ENTS-backend/pull/710)
 - [2026-03-12] fix: safely catch PyJWT DecodeErrors and remove log spam for invalid tokens [#683](https://github.com/jlab-sensing/ENTS-backend/pull/683)
 - [2026-03-12] hotfix: linted AddCellModal, ensured functionality of D10 charts, and added flags to github action pytest for logging [#703](https://github.com/jlab-sensing/ENTS-backend/pull/703)
 - [2026-03-12] hotfix: Resolve global frontend linting failure in AddCellModal [#709](https://github.com/jlab-sensing/ENTS-backend/pull/709)

backend/api/resources/logger.py

@@ -221,6 +221,9 @@ def put(self, _user, logger_id: int):
         # Update database fields
         updated = False
         if "name" in json_data:
+            existing = LoggerModel.find_by_name(json_data["name"])
+            if existing and existing.id != logger_id:
+                return {"message": "Duplicate logger name"}, 400
             logger.name = json_data.get("name")
             updated = True
         if "description" in json_data:

backend/api/schemas/cell_schema.py

@@ -1,5 +1,8 @@
 from ..schemas import ma
 from ..models.cell import Cell
+from ..models.user import (
+    User,  # noqa: F401 - ensures User is registered before SQLAlchemy mapper configures
+)
 
 
 class CellSchema(ma.SQLAlchemyAutoSchema):

backend/tests/test_logger.py

@@ -288,3 +288,49 @@ def _raise_integrity(*_args, **_kwargs):
 
     assert status == 400
     assert body["message"] == "Duplicate logger name"
+
+
+def test_put_duplicate_name_returns_400(monkeypatch):
+    """PUT /api/logger/:id with a name already used by another logger returns 400."""
+    existing_logger = StubLogger(logger_id=1)
+    target_logger = StubLogger(logger_id=2)
+
+    monkeypatch.setattr(
+        "api.resources.logger.LoggerModel.get",
+        lambda logger_id: target_logger,
+    )
+    monkeypatch.setattr(
+        "api.resources.logger.LoggerModel.find_by_name",
+        lambda name: existing_logger,  # name already taken by a different logger
+    )
+
+    app = _make_test_app()
+    with app.test_request_context(json={"name": "existing-name"}):
+        body, status = LoggerResource().put(None, logger_id=2)
+
+    assert status == 400
+    assert body["message"] == "Duplicate logger name"
+
+
+def test_put_same_name_returns_200(monkeypatch):
+    """PUT /api/logger/:id renaming to its own current name should succeed."""
+    stub_logger = StubLogger(logger_id=1)
+    stub_logger.name = "my-logger"
+    stub_logger.description = "desc"
+    stub_logger.type = ""
+    stub_logger.save = lambda: None
+
+    monkeypatch.setattr(
+        "api.resources.logger.LoggerModel.get",
+        lambda logger_id: stub_logger,
+    )
+    monkeypatch.setattr(
+        "api.resources.logger.LoggerModel.find_by_name",
+        lambda name: stub_logger,  # same logger — not a conflict
+    )
+
+    app = _make_test_app()
+    with app.test_request_context(json={"name": "my-logger"}):
+        body, status = LoggerResource().put(None, logger_id=1)
+
+    assert status == 200

frontend/src/pages/profile/components/EditLoggerModal.jsx

@@ -15,10 +15,12 @@ function EditLoggerModal({ logger }) {
   const [formData, setFormData] = useState({ ...logger });
   const [response, setResponse] = useState(null);
   const [isSubmitting, setSubmitting] = useState(false);
+  const [error, setError] = useState(null);
 
   const handleOpen = () => {
     setOpen(true);
     setResponse(null);
+    setError(null);
     setFormData({ ...logger });
   };
 
@@ -40,9 +42,13 @@ function EditLoggerModal({ logger }) {
     updateLogger(logger.id, updateData, auth?.accessToken)
       .then((res) => {
         setResponse(res);
+        setError(null);
         refetch();
       })
-      .catch((err) => console.error('Edit failed:', err))
+      .catch((err) => {
+        const msg = err?.response?.data?.message || 'Failed to update logger.';
+        setError(msg);
+      })
       .finally(() => setSubmitting(false));
   };
 
@@ -176,6 +182,21 @@ function EditLoggerModal({ logger }) {
                   />
                 </Box>
 
+                {/* Error Message */}
+                {error && (
+                  <Box sx={{
+                    mt: '1rem',
+                    p: '0.75rem 1rem',
+                    backgroundColor: '#fdecea',
+                    borderRadius: '8px',
+                    border: '1px solid #f5c6cb'
+                  }}>
+                    <Typography color='error' variant='body2'>
+                      {error}
+                    </Typography>
+                  </Box>
+                )}
+
                 {/* Action Buttons */}
                 <Box sx={{ 
                   display: 'flex',