DRY up the use of fromHex and put it in ethutil

ethutil/common_test.go

@@ -1,8 +1,10 @@
 package ethutil
 
 import (
+	"bytes"
 	"math/big"
 	"os"
+	"testing"
 
 	checker "gopkg.in/check.v1"
 )
@@ -66,3 +68,22 @@ func (s *CommonSuite) TestLarge(c *checker.C) {
 	c.Assert(adalarge, checker.Equals, "10000E7 Einstein")
 	c.Assert(weilarge, checker.Equals, "100 Babbage")
 }
+
+//fromHex
+func TestFromHex(t *testing.T) {
+	input := "0x01"
+	expected := []byte{1}
+	result := FromHex(input)
+	if bytes.Compare(expected, result) != 0 {
+		t.Errorf("Expected % x got % x", expected, result)
+	}
+}
+
+func TestFromHexOddLength(t *testing.T) {
+	input := "0x1"
+	expected := []byte{1}
+	result := FromHex(input)
+	if bytes.Compare(expected, result) != 0 {
+		t.Errorf("Expected % x got % x", expected, result)
+	}
+}