vm: implement KEYS opcode

pkg/vm/stack_item.go

@@ -19,10 +19,18 @@ func makeStackItem(v interface{}) StackItem {
 		return &BigIntegerItem{
 			value: big.NewInt(int64(val)),
 		}
+	case int64:
+		return &BigIntegerItem{
+			value: big.NewInt(val),
+		}
 	case []byte:
 		return &ByteArrayItem{
 			value: val,
 		}
+	case string:
+		return &ByteArrayItem{
+			value: []byte(val),
+		}
 	case bool:
 		return &BoolItem{
 			value: val,

pkg/vm/vm.go

@@ -912,12 +912,29 @@ func (v *VM) execute(ctx *Context, op Instruction) {
 		}
 		v.estack.PushVal(sigok)
 
-	case KEYS, VALUES:
+	case VALUES:
 		panic("unimplemented")
 
 	case NEWMAP:
 		v.estack.Push(&Element{value: NewMapItem()})
 
+	case KEYS:
+		item := v.estack.Pop()
+		if item == nil {
+			panic("no argument")
+		}
+
+		m, ok := item.value.(*MapItem)
+		if !ok {
+			panic("not a Map")
+		}
+
+		arr := make([]StackItem, 0, len(m.value))
+		for k := range m.value {
+			arr = append(arr, makeStackItem(k))
+		}
+		v.estack.PushVal(arr)
+
 	case HASKEY:
 		key := v.estack.Pop()
 		validateMapKey(key)

pkg/vm/vm_test.go

@@ -673,6 +673,40 @@ func TestSIZEBool(t *testing.T) {
 	assert.Equal(t, makeStackItem(1), vm.estack.Pop().value)
 }
 
+func TestKEYSMap(t *testing.T) {
+	prog := makeProgram(KEYS)
+	vm := load(prog)
+
+	m := NewMapItem()
+	m.Add(makeStackItem(5), makeStackItem(6))
+	m.Add(makeStackItem([]byte{0, 1}), makeStackItem(6))
+	vm.estack.Push(&Element{value: m})
+
+	vm.Run()
+	assert.Equal(t, false, vm.HasFailed())
+	assert.Equal(t, 1, vm.estack.Len())
+
+	top := vm.estack.Pop().value.(*ArrayItem)
+	assert.Equal(t, 2, len(top.value))
+	assert.Contains(t, top.value, makeStackItem(5))
+	assert.Contains(t, top.value, makeStackItem([]byte{0, 1}))
+}
+
+func TestKEYSNoArgument(t *testing.T) {
+	prog := makeProgram(KEYS)
+	vm := load(prog)
+	vm.Run()
+	assert.Equal(t, true, vm.HasFailed())
+}
+
+func TestKEYSWrongType(t *testing.T) {
+	prog := makeProgram(KEYS)
+	vm := load(prog)
+	vm.estack.PushVal([]StackItem{})
+	vm.Run()
+	assert.Equal(t, true, vm.HasFailed())
+}
+
 func TestHASKEYArrayTrue(t *testing.T) {
 	prog := makeProgram(PUSH5, NEWARRAY, PUSH4, HASKEY)
 	vm := load(prog)