Remove invariant tests for TokenMap.

The `TokenMap` type has an invariant that:
- no `mempty` values appear within the internal data structure.
- no `mempty` values appear within any encoding of a `TokenMap`.

The `MonoidMap` already guarantees to handle this invariant, and that
type is covered by a comprehensive test suite.

Therefore, there's no need to repeat those tests for the `TokenMap`
type.

lib/primitive/test/spec/Cardano/Wallet/Primitive/Types/TokenMapSpec.hs

@@ -158,35 +158,6 @@ spec =
             , ordLaws
             ]
 
-    describe
-        "All operations preserve the invariant: \
-        \all token quantities held within a map are non-zero" $ do
-
-        it "prop_arbitrary_invariant" $
-            property prop_arbitrary_invariant
-        it "prop_shrink_invariant" $
-            property prop_shrink_invariant
-        it "prop_empty_invariant" $
-            property prop_empty_invariant
-        it "prop_singleton_invariant" $
-            property prop_singleton_invariant
-        it "prop_fromFlatList_invariant" $
-            property prop_fromFlatList_invariant
-        it "prop_fromNestedList_invariant" $
-            property prop_fromNestedList_invariant
-        it "prop_add_invariant" $
-            property prop_add_invariant
-        it "prop_subtract_invariant" $
-            property prop_subtract_invariant
-        it "prop_difference_invariant" $
-            property prop_difference_invariant
-        it "prop_intersection_invariant" $
-            property prop_intersection_invariant
-        it "prop_setQuantity_invariant" $
-            property prop_setQuantity_invariant
-        it "prop_adjustQuantity_invariant" $
-            property prop_adjustQuantity_invariant
-
     describe "Construction and deconstruction" $ do
 
         it "prop_fromFlatList" $
@@ -343,69 +314,6 @@ spec =
         it "Nested style" $
             property testPrettyNested
 
---------------------------------------------------------------------------------
--- Invariant properties
---------------------------------------------------------------------------------
-
--- Tests that all quantities within the given map are non-zero.
---
-invariantHolds :: TokenMap -> Bool
-invariantHolds b =
-    all TokenQuantity.isNonZero $ getQuantity <$> TokenMap.toFlatList b
-  where
-    getQuantity (_, q) = q
-
-prop_arbitrary_invariant :: TokenMap -> Property
-prop_arbitrary_invariant = property . invariantHolds
-
-prop_shrink_invariant :: TokenMap -> Property
-prop_shrink_invariant b = property $ all invariantHolds $ shrink b
-
-prop_empty_invariant :: Property
-prop_empty_invariant = property $ invariantHolds TokenMap.empty
-
-prop_singleton_invariant :: (AssetId, TokenQuantity) -> Property
-prop_singleton_invariant (asset, quantity) = property $
-    invariantHolds $ TokenMap.singleton asset quantity
-
-prop_fromFlatList_invariant :: [(AssetId, TokenQuantity)] -> Property
-prop_fromFlatList_invariant entries =
-    property $ invariantHolds $ TokenMap.fromFlatList entries
-
-prop_fromNestedList_invariant
-    :: [(TokenPolicyId, NonEmpty (TokenName, TokenQuantity))] -> Property
-prop_fromNestedList_invariant entries =
-    property $ invariantHolds $ TokenMap.fromNestedList entries
-
-prop_add_invariant :: TokenMap -> TokenMap -> Property
-prop_add_invariant b1 b2 = property $ invariantHolds $ TokenMap.add b1 b2
-
-prop_subtract_invariant :: TokenMap -> TokenMap -> Property
-prop_subtract_invariant m1 m2 = property $
-    m2 `leq` m1 ==> invariantHolds result
-  where
-    result =
-        case TokenMap.subtract m1 m2 of
-            Nothing -> error "prop_subtract_invariant"
-            Just r -> r
-
-prop_difference_invariant :: TokenMap -> TokenMap -> Property
-prop_difference_invariant m1 m2 =
-    property $ invariantHolds $ TokenMap.difference m1 m2
-
-prop_intersection_invariant :: TokenMap -> TokenMap -> Property
-prop_intersection_invariant m1 m2 =
-    property $ invariantHolds $ TokenMap.intersection m1 m2
-
-prop_setQuantity_invariant
-    :: TokenMap -> AssetId -> TokenQuantity -> Property
-prop_setQuantity_invariant b asset quantity = property $
-    invariantHolds $ TokenMap.setQuantity b asset quantity
-
-prop_adjustQuantity_invariant :: TokenMap -> AssetId -> Property
-prop_adjustQuantity_invariant b asset = property $
-    invariantHolds $ TokenMap.adjustQuantity b asset TokenQuantity.predZero
-
 --------------------------------------------------------------------------------
 -- Construction and deconstruction properties
 --------------------------------------------------------------------------------