common: Improve IsHex and IsHexAddress & add tests

common/bytes.go

@@ -17,9 +17,7 @@
 // Package common contains various helper functions.
 package common
 
-import (
+import "encoding/hex"
-	"encoding/hex"
-)
 
 func ToHex(b []byte) string {
 	hex := Bytes2Hex(b)
@@ -57,12 +55,28 @@ func CopyBytes(b []byte) (copiedBytes []byte) {
 
 func HasHexPrefix(str string) bool {
 	l := len(str)
-	return l >= 2 && str[0:2] == "0x"
+	return l >= 2 && (str[0:2] == "0x" || str[0:2] == "0X")
+}
+
+func isHexCharacter(c byte) bool {
+	return ('0' <= c && c <= '9') ||
+		('a' <= c && c <= 'f') ||
+		('A' <= c && c <= 'F')
 }
 
 func IsHex(str string) bool {
-	l := len(str)
+	if HasHexPrefix(str) {
-	return l >= 4 && l%2 == 0 && str[0:2] == "0x"
+		str = str[2:]
+	}
+	if len(str)%2 != 0 {
+		return false
+	}
+	for _, c := range []byte(src) {
+		if !isHexCharacter(c) {
+			return false
+		}
+	}
+	return true
 }
 
 func Bytes2Hex(d []byte) string {

common/bytes_test.go

@@ -36,7 +36,7 @@ func (s *BytesSuite) TestCopyBytes(c *checker.C) {
 
 func (s *BytesSuite) TestIsHex(c *checker.C) {
 	data1 := "a9e67e"
-	exp1 := false
+	exp1 := true
 	res1 := IsHex(data1)
 	c.Assert(res1, checker.DeepEquals, exp1)
 
@@ -45,6 +45,15 @@ func (s *BytesSuite) TestIsHex(c *checker.C) {
 	res2 := IsHex(data2)
 	c.Assert(res2, checker.DeepEquals, exp2)
 
+	data3 := "0xa9e67e001"
+	exp3 := false
+	res3 := IsHex(data3)
+	c.Assert(res3, checker.DeepEquals, exp3)
+
+	data4 := "0xHELLO_MY_NAME_IS_STEVEN_@#$^&*"
+	exp4 := false
+	res4 := IsHex(data4)
+	c.Assert(res4, checker.DeepEquals, exp4)
 }
 
 func (s *BytesSuite) TestLeftPadBytes(c *checker.C) {

common/types.go

@@ -150,13 +150,10 @@ func HexToAddress(s string) Address    { return BytesToAddress(FromHex(s)) }
 // IsHexAddress verifies whether a string can represent a valid hex-encoded
 // Ethereum address or not.
 func IsHexAddress(s string) bool {
-	if len(s) == 2+2*AddressLength && IsHex(s) {
+	if HasHexPrefix(s) {
-		return true
+		return len(s) == 2+2*AddressLength && IsHex(s[2:])
 	}
-	if len(s) == 2*AddressLength && IsHex("0x"+s) {
+	return len(s) == 2*AddressLength && IsHex(s)
-		return true
-	}
-	return false
 }
 
 // Get the string representation of the underlying address

common/types_test.go

@@ -35,6 +35,30 @@ func TestBytesConversion(t *testing.T) {
 	}
 }
 
+func TestIsHexAddress(t *testing.T) {
+	tests := []struct {
+		str string
+		exp bool
+	}{
+		{"0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed", true},
+		{"5aaeb6053f3e94c9b9a09f33669435e7ef1beaed", true},
+		{"0X5aaeb6053f3e94c9b9a09f33669435e7ef1beaed", true},
+		{"0XAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", true},
+		{"0xAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", true},
+		{"0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed1", false},
+		{"0x5aaeb6053f3e94c9b9a09f33669435e7ef1beae", false},
+		{"5aaeb6053f3e94c9b9a09f33669435e7ef1beaed11", false},
+		{"0xxaaeb6053f3e94c9b9a09f33669435e7ef1beaed", false},
+	}
+
+	for _, test := range tests {
+		if result := IsHexAddress(test.str); result != test.exp {
+			t.Errorf("IsHexAddress(%s) == %v; expected %v",
+				test.str, result, test.exp)
+		}
+	}
+}
+
 func TestHashJsonValidation(t *testing.T) {
 	var tests = []struct {
 		Prefix string