fix fractional resoure handling for batch (#1089)

Author: oavdeev

metaflow/plugins/aws/aws_utils.py

@@ -79,7 +79,11 @@ def compute_resource_attributes(decos, compute_deco, resource_defaults):
                     continue
                 if my_val is not None and v is not None:
                     try:
-                        result[k] = str(max(int(my_val or 0), int(v or 0)))
+                        # Use Decimals to compare and convert to string here so
+                        # that numbers that can't be exactly represented as
+                        # floats (e.g. 0.8) still look "nice". We don't care
+                        # about precision more that .001 for resources anyway.
+                        result[k] = str(max(float(my_val or 0), float(v or 0)))
                     except ValueError:
                         # Here, we don't have ints so we compare the value and raise
                         # an exception if not equal

test/unit/test_compute_resource_attributes.py

@@ -39,7 +39,17 @@ def test_compute_resource_attributes():
             MockDeco("batch", {"cpu": 1}),
             {"cpu": "3"},
         )
-        == {"cpu": "2"}
+        == {"cpu": "2.0"}
+    )
+
+    # take largest of @resources and @batch if both are present
+    assert (
+        compute_resource_attributes(
+            [MockDeco("resources", {"cpu": 0.83})],
+            MockDeco("batch", {"cpu": "0.5"}),
+            {"cpu": "1"},
+        )
+        == {"cpu": "0.83"}
     )