Add common> Idx parsers

common/tx_test.go

@@ -0,0 +1,23 @@
+package common
+
+import (
+	"math/big"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIdx(t *testing.T) {
+	i := Idx(100)
+	assert.Equal(t, big.NewInt(100), i.BigInt())
+
+	i = Idx(uint32(4294967295))
+	assert.Equal(t, "4294967295", i.BigInt().String())
+
+	b := big.NewInt(4294967296)
+	i, err := IdxFromBigInt(b)
+	assert.NotNil(t, err)
+	assert.Equal(t, ErrNumOverflow, err)
+	assert.Equal(t, Idx(0), i)
+
+}