More intuitive display of negative time deltas (#8274)

superset/utils/core.py

@@ -349,6 +349,23 @@ def datetime_f(dttm):
     return "<nobr>{}</nobr>".format(dttm)
 
 
+def format_timedelta(td: timedelta) -> str:
+    """
+    Ensures negative time deltas are easily interpreted by humans
+
+    >>> td = timedelta(0) - timedelta(days=1, hours=5,minutes=6)
+    >>> str(td)
+    '-2 days, 18:54:00'
+    >>> format_timedelta(td)
+    '-1 day, 5:06:00'
+    """
+    if td < timedelta(0):
+        return "-" + str(abs(td))
+    else:
+        # Change this to format positive time deltas the way you want
+        return str(td)
+
+
 def base_json_conv(obj):
     if isinstance(obj, memoryview):
         obj = obj.tobytes()
@@ -363,7 +380,7 @@ def base_json_conv(obj):
     elif isinstance(obj, uuid.UUID):
         return str(obj)
     elif isinstance(obj, timedelta):
-        return str(obj)
+        return format_timedelta(obj)
     elif isinstance(obj, bytes):
         try:
             return obj.decode("utf-8")

tests/utils_tests.py

@@ -32,6 +32,7 @@
     base_json_conv,
     convert_legacy_filters_into_adhoc,
     datetime_f,
+    format_timedelta,
     get_or_create_db,
     get_since_until,
     get_stacktrace,
@@ -120,6 +121,7 @@ def test_base_json_conv(self):
         assert isinstance(base_json_conv(set([1])), list) is True
         assert isinstance(base_json_conv(Decimal("1.0")), float) is True
         assert isinstance(base_json_conv(uuid.uuid4()), str) is True
+        assert isinstance(base_json_conv(timedelta(0)), str) is True
 
     @patch("superset.utils.core.datetime")
     def test_parse_human_timedelta(self, mock_datetime):
@@ -535,6 +537,19 @@ def test_datetime_f(self):
         [a, b, c] = [int(v) for v in iso]
         self.assertEquals(datetime_f(datetime(a, b, c)), "<nobr>00:00:00</nobr>")
 
+    def test_format_timedelta(self):
+        self.assertEquals(format_timedelta(timedelta(0)), "0:00:00")
+        self.assertEquals(format_timedelta(timedelta(days=1)), "1 day, 0:00:00")
+        self.assertEquals(format_timedelta(timedelta(minutes=-6)), "-0:06:00")
+        self.assertEquals(
+            format_timedelta(timedelta(0) - timedelta(days=1, hours=5, minutes=6)),
+            "-1 day, 5:06:00",
+        )
+        self.assertEquals(
+            format_timedelta(timedelta(0) - timedelta(days=16, hours=4, minutes=3)),
+            "-16 days, 4:03:00",
+        )
+
     def test_json_encoded_obj(self):
         obj = {"a": 5, "b": ["a", "g", 5]}
         val = '{"a": 5, "b": ["a", "g", 5]}'