test: update test_clear and test_clear_nocache to test the new ca…

…chemap deletion behaviour

These tests call `.clear()` on a non-existent cache key.
Previously, this would have resulted in an exception being thrown.
The new behaviour should be to throw no exceptions.

tests/test_dataloaders.py

@@ -288,6 +288,10 @@ async def idx(keys: List[int]) -> List[Tuple[int, int]]:
 
     assert await loader.load_many([1, 2, 3]) == [(1, 4), (2, 4), (3, 4)]
 
+    loader.clear(-1)
+
+    assert await loader.load_many([1, 2, 3]) == [(1, 4), (2, 4), (3, 4)]
+
 
 @pytest.mark.asyncio
 async def test_clear_nocache():
@@ -301,11 +305,6 @@ async def idx(keys: List[int]) -> List[Tuple[int, int]]:
 
     loader = DataLoader(load_fn=idx, cache=False)
 
-    try:
-        loader.clean(1)  # no effect on non-cached values
-    except Exception as e:
-        raise AssertionError("clean non-cached values does not raise KeyError")
-
     assert await loader.load_many([1, 2, 3]) == [(1, 1), (2, 1), (3, 1)]
 
     loader.clear(1)
@@ -320,6 +319,10 @@ async def idx(keys: List[int]) -> List[Tuple[int, int]]:
 
     assert await loader.load_many([1, 2, 3]) == [(1, 4), (2, 4), (3, 4)]
 
+    loader.clear(-1)
+
+    assert await loader.load_many([1, 2, 3]) == [(1, 5), (2, 5), (3, 5)]
+
 
 @pytest.mark.asyncio
 async def test_dont_dispatch_cancelled():