add more corner case tests

erddapy/core/url.py

@@ -23,14 +23,19 @@ def _sort_url(url):
     """
     parts = parse.urlparse(url)
     if parts.query:
-        variables, constraints = parts.query.split("&", maxsplit=1)
+        query = parts.query.split("&", maxsplit=1)
+        if len(query) == 1:
+            variables = parts.query
+            constraints = ""
+        else:
+            variables, constraints = parts.query.split("&", maxsplit=1)
         sorted_variables = ",".join(sorted(variables.split(",")))
         sorted_query = OrderedDict(sorted(dict(parse.parse_qsl(constraints)).items()))
         sorted_query_str = parse.unquote(parse.urlencode(sorted_query))
         sorted_url = f"{parts.scheme}://{parts.netloc}{parts.path}?{parts.params}{sorted_variables}&{sorted_query_str}{parts.fragment}"
     else:
         sorted_url = url
-    return sorted_url
+    return sorted_url.strip("&")
 
 
 @functools.lru_cache(maxsize=128)

tests/test_to_objects.py

@@ -212,9 +212,35 @@ def test_download_file(dataset_tabledap):
 
 
 @pytest.mark.web
-def test_download_file_undefined_query(dataset_tabledap):
+def test_download_file_variables_only(dataset_tabledap):
+    """Test direct download of tabledap dataset with undefined constraints."""
+    dataset_tabledap.constraints = {}
+    fn = dataset_tabledap.download_file("nc")
+    ds = xr.load_dataset(fn)
+    assert ds["time"].name == "time"
+    assert ds["temperature"].name == "temperature"
+    dataset_tabledap.variables = dataset_tabledap.variables[::-1]
+    fn_new = dataset_tabledap.download_file("nc")
+    assert fn_new == fn
+
+
+@pytest.mark.web
+def test_download_file_constraints_only(dataset_tabledap):
     """Test direct download of tabledap dataset with undefined constraints."""
     dataset_tabledap.variables = []
+    fn = dataset_tabledap.download_file("nc")
+    ds = xr.load_dataset(fn)
+    assert ds["time"].name == "time"
+    assert ds["temperature"].name == "temperature"
+    dataset_tabledap.variables = dataset_tabledap.variables[::-1]
+    fn_new = dataset_tabledap.download_file("nc")
+    assert fn_new == fn
+
+
+@pytest.mark.web
+def test_download_file_undefined_query(dataset_tabledap):
+    """Test direct download of tabledap dataset with undefined variables and constraints."""
+    dataset_tabledap.variables = []
     dataset_tabledap.constraints = {}
     fn = dataset_tabledap.download_file("nc")
     ds = xr.load_dataset(fn)

tests/test_url_handling.py

@@ -5,7 +5,7 @@
 import httpx
 import pytest
 
-from erddapy.core.url import check_url_response, urlopen
+from erddapy.core.url import _sort_url, check_url_response, urlopen
 
 
 @pytest.mark.web
@@ -39,3 +39,26 @@ def test_check_url_response():
     )
     with pytest.raises(httpx.HTTPError):
         check_url_response(bad_request)
+
+
+def test__sort_url():
+    url = "https://erddap.sensors.ioos.us/erddap/tabledap/amelia_20180501t0000.nc?time,temperature&time>=1525737600.0&time<=1526245200.0&latitude>=36&latitude<=38&longitude>=-76&longitude<=-73"
+    expected = "https://erddap.sensors.ioos.us/erddap/tabledap/amelia_20180501t0000.nc?temperature,time&latitude<=38&latitude>=36&longitude<=-73&longitude>=-76&time<=1526245200.0&time>=1525737600.0"
+    assert _sort_url(url) == expected
+
+
+def test__sort_url_variables_only():
+    url = "https://erddap.sensors.ioos.us/erddap/tabledap/amelia_20180501t0000.nc?&time>=1525737600.0&time<=1526245200.0&latitude>=36&latitude<=38&longitude>=-76&longitude<=-73"
+    expected = "https://erddap.sensors.ioos.us/erddap/tabledap/amelia_20180501t0000.nc?&latitude<=38&latitude>=36&longitude<=-73&longitude>=-76&time<=1526245200.0&time>=1525737600.0"
+    assert _sort_url(url) == expected
+
+
+def test__sort_url_constraints_only():
+    url = "https://erddap.sensors.ioos.us/erddap/tabledap/amelia_20180501t0000.nc?time,temperature"
+    expected = "https://erddap.sensors.ioos.us/erddap/tabledap/amelia_20180501t0000.nc?temperature,time"
+    assert _sort_url(url) == expected
+
+
+def test__sort_url_undefined_query():
+    url = "https://erddap.sensors.ioos.us/erddap/tabledap/amelia_20180501t0000.nc?"
+    assert _sort_url(url) == url