Fix Modular Exponentiation Test

[tk-codes]

At the end of the function call (ret), evaluation stack should be empty.

The following test has more values. It should be fixed.

func TestVm_Exec_ModularExponentiation_ContractImplementation(t *testing.T) {
	code := []byte{
		PushInt, 1, 0, 4, // Base 4
		PushInt, 2, 0, 1, 241, // Modulus 497

		// Address 9
		// IF modulus equals 0
		Dup,
		PushInt, 0,
		Eq,
		JmpTrue, 0, 42, // Adjust address

		// Address 16
		PushInt, 1, 0, 1, // Counter (c)
		PushInt, 0, //i
		PushInt, 1, 0, 13, // Exp

		// Address 26
		//LOOP start: Stack: [[0 13] [0] [0 1] [0 1 241] [0 4]]
		Roll, 2,
		//Duplicate arguments
		Dup, //Stack: [[0 11 75] [0 11 75] [0 13] [0] [0 1] [0 4]]
		Roll, 4,
		Dup, // STACK Stack: [[04] [0 4] [0 11 75] [0 11 75] [0 13] [0 0] [0 1]]
		// PUT in order
		Roll, 1, //Stack: [[0 11 75] [0 4] [0 4] [0 11 75] [0 13] [0 0] [0 1]]
		Roll, 4, //Stack: [[0 0] [0 11 75] [0 4] [0 4] [0 11 75] [0 13] [0 1]]
		Roll, 4, //Stack: [[0 13] [0 0] [0 11 75] [0 4] [0 4] [0 11 75] [0 1]]
		Roll, 3, //Stack: [[0 4] [0 13] [0 0] [0 11 75] [0 4] [0 11 75] [0 1]]
		Roll, 4, //Stack: [[0 11 75] [0 4] [0 13] [0 0] [0 11 75] [0 4] [0 1]]
		Roll, 5, //Stack: [[0 1] [0 11 75] [0 4] [0 13] [0 0] [0 11 75] [0 4]]

		// Address 44
		// Order: counter, modulus, base, exp, i, modulus, base
		Call, 0, 73, 3, 1,
		// PUT in order
		Roll, 1,
		Roll, 1,

		// Address 53
		// Order: exp, i - counter, modulus, base,
		Dup,
		Roll, 1,
		PushInt, 1, 0, 1,
		Add,
		Dup,
		Roll, 1,
		Roll, 1,
		Roll, 2,
		Lt,
		JmpTrue, 0, 26, // Adjust address
		// LOOP END
		Halt,

		// Address 77
		// FUNCTION Order: c, modulus, base,
		LoadLoc, 2,
		LoadLoc, 0,
		Mul,
		LoadLoc, 1,
		Mod,
		Ret,
	}

	vm := NewTestVM([]byte{})
	mc := NewMockContext(code)
	mc.Fee = 1000
	vm.context = mc
	vm.Exec(true)

	expected := 445
	vm.evaluationStack.Pop()
	vm.evaluationStack.Pop()
	actual, _ := vm.evaluationStack.Pop()

	if ByteArrayToInt(actual[1:]) != expected {
		t.Errorf("Expected actual result to be '%v' but was '%v'", expected, actual)
	}
}

[skas102]

We commented out the test. Currently it fails as we added a check to case Ret: which checks that the evaluation stack does habe the same amount of elements on it as the function has return types.

E.g. function (int, bool) test() {} has two return types (int and bool) and should therefore have two elements on the evaluation stack at the end of the function.

[tk-codes]

Resolved in #37