skip missing check if no time in variable (#382)

<!-- Please ensure the PR fulfills the following requirements! -->
<!-- If this is your first PR, make sure to add your details to the
AUTHORS.rst! -->
### Pull Request Checklist:
- [x] This PR addresses an already opened issue (for bug fixes /
features)
    - This PR fixes #xyz
- [x] (If applicable) Documentation has been added / updated (for bug
fixes / features).
- [x] (If applicable) Tests have been added.
- [x] This PR does not seem to break the templates.
- [x] CHANGES.rst has been updated (with summary of main changes).
- [x] Link to issue (:issue:`number`) and pull request (:pull:`number`)
has been added.

### What kind of change does this PR introduce?

* Added a check to make sure that the `time` dimension exists for the
variable before checking for missing data.

### Does this PR introduce a breaking change?

* No.

### Other information:

CHANGES.rst

@@ -34,6 +34,7 @@ Bug fixes
 * `creep_weights` now correctly handles the case where the grid is small, `n` is large, and `mode=wrap`. (:issue:`367`).
 * Fixed a bug in ``tasmin_from_dtr`` and ``tasmax_from_dtr``, when `dtr` units differed from tasmin/max. (:pull:`372`).
 * Fixed a bug where the requested chunking would be ignored when saving a dataset (:pull:`379`).
+* The missing value check in ``health_checks`` will no longer crasg if a variable has no time dimension. (:pull:`382`).
 
 v0.8.3 (2024-02-28)
 -------------------

xscen/diagnostics.py

@@ -262,11 +262,16 @@ def _message():
             for method, kwargs in missing.items():
                 kwargs.setdefault("freq", "YS")
                 for v in ds.data_vars:
-                    ms = getattr(xc.core.missing, method)(ds[v], **kwargs)
-                    if ms.any():
-                        _error(
-                            f"The variable '{v}' has missing values according to the '{method}' method.",
-                            "missing",
+                    if "time" in ds[v].dims:
+                        ms = getattr(xc.core.missing, method)(ds[v], **kwargs)
+                        if ms.any():
+                            _error(
+                                f"The variable '{v}' has missing values according to the '{method}' method.",
+                                "missing",
+                            )
+                    else:
+                        logger.info(
+                            f"Variable '{v}' has no time dimension. The missing data check will be skipped.",
                         )
 
     if flags is not None: