common/hexutil: new package for 0x hex encoding

The new package is purpose-built to handle the encoding consumed and
produced by the RPC API.

common/hexutil/hexutil_test.go

@@ -0,0 +1,186 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package hexutil
+
+import (
+	"bytes"
+	"encoding/hex"
+	"math/big"
+	"testing"
+)
+
+type marshalTest struct {
+	input interface{}
+	want  string
+}
+
+type unmarshalTest struct {
+	input   string
+	want    interface{}
+	wantErr error
+}
+
+var (
+	encodeBytesTests = []marshalTest{
+		{[]byte{}, "0x"},
+		{[]byte{0}, "0x00"},
+		{[]byte{0, 0, 1, 2}, "0x00000102"},
+	}
+
+	encodeBigTests = []marshalTest{
+		{referenceBig("0"), "0x0"},
+		{referenceBig("1"), "0x1"},
+		{referenceBig("ff"), "0xff"},
+		{referenceBig("112233445566778899aabbccddeeff"), "0x112233445566778899aabbccddeeff"},
+	}
+
+	encodeUint64Tests = []marshalTest{
+		{uint64(0), "0x0"},
+		{uint64(1), "0x1"},
+		{uint64(0xff), "0xff"},
+		{uint64(0x1122334455667788), "0x1122334455667788"},
+	}
+
+	decodeBytesTests = []unmarshalTest{
+		// invalid
+		{input: ``, wantErr: ErrEmptyString},
+		{input: `0`, wantErr: ErrMissingPrefix},
+		{input: `0x0`, wantErr: hex.ErrLength},
+		{input: `0x023`, wantErr: hex.ErrLength},
+		{input: `0xxx`, wantErr: hex.InvalidByteError('x')},
+		{input: `0x01zz01`, wantErr: hex.InvalidByteError('z')},
+		// valid
+		{input: `0x`, want: []byte{}},
+		{input: `0X`, want: []byte{}},
+		{input: `0x02`, want: []byte{0x02}},
+		{input: `0X02`, want: []byte{0x02}},
+		{input: `0xffffffffff`, want: []byte{0xff, 0xff, 0xff, 0xff, 0xff}},
+		{
+			input: `0xffffffffffffffffffffffffffffffffffff`,
+			want:  []byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
+		},
+	}
+
+	decodeBigTests = []unmarshalTest{
+		// invalid
+		{input: `0`, wantErr: ErrMissingPrefix},
+		{input: `0x`, wantErr: ErrEmptyNumber},
+		{input: `0x01`, wantErr: ErrLeadingZero},
+		{input: `0xx`, wantErr: ErrSyntax},
+		{input: `0x1zz01`, wantErr: ErrSyntax},
+		// valid
+		{input: `0x0`, want: big.NewInt(0)},
+		{input: `0x2`, want: big.NewInt(0x2)},
+		{input: `0x2F2`, want: big.NewInt(0x2f2)},
+		{input: `0X2F2`, want: big.NewInt(0x2f2)},
+		{input: `0x1122aaff`, want: big.NewInt(0x1122aaff)},
+		{input: `0xbBb`, want: big.NewInt(0xbbb)},
+		{input: `0xfffffffff`, want: big.NewInt(0xfffffffff)},
+		{
+			input: `0x112233445566778899aabbccddeeff`,
+			want:  referenceBig("112233445566778899aabbccddeeff"),
+		},
+		{
+			input: `0xffffffffffffffffffffffffffffffffffff`,
+			want:  referenceBig("ffffffffffffffffffffffffffffffffffff"),
+		},
+	}
+
+	decodeUint64Tests = []unmarshalTest{
+		// invalid
+		{input: `0`, wantErr: ErrMissingPrefix},
+		{input: `0x`, wantErr: ErrEmptyNumber},
+		{input: `0x01`, wantErr: ErrLeadingZero},
+		{input: `0xfffffffffffffffff`, wantErr: ErrUintRange},
+		{input: `0xx`, wantErr: ErrSyntax},
+		{input: `0x1zz01`, wantErr: ErrSyntax},
+		// valid
+		{input: `0x0`, want: uint64(0)},
+		{input: `0x2`, want: uint64(0x2)},
+		{input: `0x2F2`, want: uint64(0x2f2)},
+		{input: `0X2F2`, want: uint64(0x2f2)},
+		{input: `0x1122aaff`, want: uint64(0x1122aaff)},
+		{input: `0xbbb`, want: uint64(0xbbb)},
+		{input: `0xffffffffffffffff`, want: uint64(0xffffffffffffffff)},
+	}
+)
+
+func TestEncode(t *testing.T) {
+	for _, test := range encodeBytesTests {
+		enc := Encode(test.input.([]byte))
+		if enc != test.want {
+			t.Errorf("input %x: wrong encoding %s", test.input, enc)
+		}
+	}
+}
+
+func TestDecode(t *testing.T) {
+	for _, test := range decodeBytesTests {
+		dec, err := Decode(test.input)
+		if !checkError(t, test.input, err, test.wantErr) {
+			continue
+		}
+		if !bytes.Equal(test.want.([]byte), dec) {
+			t.Errorf("input %s: value mismatch: got %x, want %x", test.input, dec, test.want)
+			continue
+		}
+	}
+}
+
+func TestEncodeBig(t *testing.T) {
+	for _, test := range encodeBigTests {
+		enc := EncodeBig(test.input.(*big.Int))
+		if enc != test.want {
+			t.Errorf("input %x: wrong encoding %s", test.input, enc)
+		}
+	}
+}
+
+func TestDecodeBig(t *testing.T) {
+	for _, test := range decodeBigTests {
+		dec, err := DecodeBig(test.input)
+		if !checkError(t, test.input, err, test.wantErr) {
+			continue
+		}
+		if dec.Cmp(test.want.(*big.Int)) != 0 {
+			t.Errorf("input %s: value mismatch: got %x, want %x", test.input, dec, test.want)
+			continue
+		}
+	}
+}
+
+func TestEncodeUint64(t *testing.T) {
+	for _, test := range encodeUint64Tests {
+		enc := EncodeUint64(test.input.(uint64))
+		if enc != test.want {
+			t.Errorf("input %x: wrong encoding %s", test.input, enc)
+		}
+	}
+}
+
+func TestDecodeUint64(t *testing.T) {
+	for _, test := range decodeUint64Tests {
+		dec, err := DecodeUint64(test.input)
+		if !checkError(t, test.input, err, test.wantErr) {
+			continue
+		}
+		if dec != test.want.(uint64) {
+			t.Errorf("input %s: value mismatch: got %x, want %x", test.input, dec, test.want)
+			continue
+		}
+	}
+}