MemoryLeaks test: measure entire IWorld size, except share names

Tests/MemoryLeaks.icl

@@ -19,10 +19,10 @@ repetitions =: 1000
 
 tests :: [UnitTest]
 tests =:
-	[ memoryConsumptionOf "recursive step"          getSharesSize
-	, memoryConsumptionOf "local share"             (withShared 3 \_ -> getSharesSize)
-	, memoryConsumptionOf "parallel task"           (viewInformation [] 3 ||- getSharesSize)
-	, memoryConsumptionOf "shared interaction task" (withShared 3 \sds -> viewSharedInformation [] sds ||- getSharesSize)
+	[ memoryConsumptionOf "recursive step"          getIWorldSize
+	, memoryConsumptionOf "local share"             (withShared 3 \_ -> getIWorldSize)
+	, memoryConsumptionOf "parallel task"           (viewInformation [] 3 ||- getIWorldSize)
+	, memoryConsumptionOf "shared interaction task" (withShared 3 \sds -> viewSharedInformation [] sds ||- getIWorldSize)
 	]
 
 memoryConsumptionOf :: !String !(Task Int) -> UnitTest
@@ -54,9 +54,16 @@ where
 					CustomFailReason $
 						concat ["Memory consumption increased by ", toString $ endSize - initSize, " bytes."]
 
-getSharesSize :: Task Int
-getSharesSize = mkInstantTask \_ iworld=:{memoryShares}
-	-> (Ok ('Map'.foldrNoKey ((+) o nodeSize) 0 memoryShares), iworld)
-where
-	nodeSize :: !.a -> Int
-	nodeSize x = size (copy_to_string x)
+/* NB: We subtract the size of the names of shares. Because share names include
+ * TaskIds in string representation, and these IDs are incremented, including
+ * share names may cause the IWorld size to increase; we want to ignore these
+ * small changes.
+ */
+getIWorldSize :: Task Int
+getIWorldSize = mkInstantTask \_ iworld=:{memoryShares}
+	# iworldString = copy_to_string iworld
+	# (iworldSize,iworldString) = usize iworldString
+	# (iworld,_) = copy_from_string iworldString
+	# shareNamesSize = 'Map'.foldrWithKey` (\k _ n -> n + size (copy_to_string k)) 0 memoryShares
+		// We cannot simply fold with `size k` due to padding in `copy_to_string`.
+	-> (Ok (iworldSize - shareNamesSize), iworld)