more complete test

zokrates_core_test/tests/tests/pass_by_value.json

@@ -1,14 +1,14 @@
 {
-	"entry_point": "./tests/tests/structs/mutate_argument.zok",
+	"entry_point": "./tests/tests/pass_by_value.zok",
 	"curves": ["Bn128", "Bls12_381", "Bls12_377", "Bw6_761"],
 	"tests": [
 		{
 			"input": {
-				"values": ["1"]
+				"values": ["1", "1", "1"]
 			},
 			"output": {
 				"Ok": {
-					"values": ["2", "1"]
+					"values": ["2", "1", "2", "1", "2", "1"]
 				}
 			}
 		}

zokrates_core_test/tests/tests/pass_by_value.zok

@@ -0,0 +1,18 @@
+struct Foo {
+    field a
+}
+
+def mutate(field a) -> field:
+    a = a + 1
+    return a
+
+def mutate(Foo f) -> Foo:
+    f.a = f.a + 1
+    return f
+
+def mutate(field[1] f) -> field[1]:
+    f[0] = f[0] + 1
+    return f
+
+def main(field[1] f, Foo g, field h) -> (field[1], field[1], Foo, Foo, field, field):
+    return mutate(f), f, mutate(g), g, mutate(h), h 

zokrates_core_test/tests/tests/structs/mutate_argument.zok

@@ -1,10 +0,0 @@
-struct Foo {
-    field a
-}
-
-def mutate(field[1] f) -> field[1]:
-    f[0] = f[0] + 1
-    return f
-
-def main(field[1] f) -> (field[1], field[1]):
-    return mutate(f), f