golf coverage

list/list_test.go

@@ -29,12 +29,14 @@ func TestConjIncreasesLength(t *testing.T) {
 	})
 }
 
-func TestRestDecreasesLengthForNonEmptyList(t *testing.T) {
+func TestRestDecreasesLength(t *testing.T) {
 	rapid.Check(t, func(t *rapid.T) {
-		myList := intListGen().Filter(func(l IList) bool {
-			return !l.IsEmpty()
-		}).Draw(t, "myList")
-		assert.Equal(t, myList.Len()-1, myList.Rest().Len())
+		myList := intListGen().Draw(t, "myList")
+		if myList.IsEmpty() {
+			assert.Equal(t, 0, myList.Rest().Len())
+		} else {
+			assert.Equal(t, myList.Len()-1, myList.Rest().Len())
+		}
 	})
 }