Merge pull request #1 from tgerring/tests

Initial tests based on check framework

10 files changed, 492 insertions, 93 deletions

diff --git a/ethutil/big_test.go b/ethutil/big_test.go
new file mode 100644
index 000000000..bf3c96c6d
--- /dev/null
+++ b/ethutil/big_test.go
@@ -0,0 +1,73 @@
+package ethutil
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestMisc(t *testing.T) {
+	a := Big("10")
+	b := Big("57896044618658097711785492504343953926634992332820282019728792003956564819968")
+	c := []byte{1, 2, 3, 4}
+	z := BitTest(a, 1)
+
+	if z != true {
+		t.Error("Expected true got", z)
+	}
+
+	U256(a)
+	S256(a)
+
+	U256(b)
+	S256(b)
+
+	BigD(c)
+}
+
+func TestBigMax(t *testing.T) {
+	a := Big("10")
+	b := Big("5")
+
+	max1 := BigMax(a, b)
+	if max1 != a {
+		t.Errorf("Expected %d got %d", a, max1)
+	}
+
+	max2 := BigMax(b, a)
+	if max2 != a {
+		t.Errorf("Expected %d got %d", a, max2)
+	}
+}
+
+func TestBigMin(t *testing.T) {
+	a := Big("10")
+	b := Big("5")
+
+	min1 := BigMin(a, b)
+	if min1 != b {
+		t.Errorf("Expected %d got %d", b, min1)
+	}
+
+	min2 := BigMin(b, a)
+	if min2 != b {
+		t.Errorf("Expected %d got %d", b, min2)
+	}
+}
+
+func TestBigCopy(t *testing.T) {
+	a := Big("10")
+	b := BigCopy(a)
+	c := Big("1000000000000")
+	y := BigToBytes(b, 16)
+	ybytes := []byte{0, 10}
+	z := BigToBytes(c, 16)
+	zbytes := []byte{232, 212, 165, 16, 0}
+
+	if bytes.Compare(y, ybytes) != 0 {
+		t.Error("Got", ybytes)
+	}
+
+	if bytes.Compare(z, zbytes) != 0 {
+		t.Error("Got", zbytes)
+	}
+}
diff --git a/ethutil/bytes_test.go b/ethutil/bytes_test.go
index 381efe7a2..179a8c7ef 100644
--- a/ethutil/bytes_test.go
+++ b/ethutil/bytes_test.go
@@ -1,14 +1,193 @@
 package ethutil
 
 import (
-	"bytes"
-	"testing"
+	checker "gopkg.in/check.v1"
 )
 
-func TestParseData(t *testing.T) {
-	data := ParseData("hello", "world", "0x0106")
-	exp := "68656c6c6f000000000000000000000000000000000000000000000000000000776f726c640000000000000000000000000000000000000000000000000000000106000000000000000000000000000000000000000000000000000000000000"
-	if bytes.Compare(data, Hex2Bytes(exp)) != 0 {
-		t.Error("Error parsing data")
-	}
+type BytesSuite struct{}
+
+var _ = checker.Suite(&BytesSuite{})
+
+func (s *BytesSuite) TestByteString(c *checker.C) {
+	var data Bytes
+	data = []byte{102, 111, 111}
+	exp := "foo"
+	res := data.String()
+
+	c.Assert(res, checker.Equals, exp)
+}
+
+/*
+func (s *BytesSuite) TestDeleteFromByteSlice(c *checker.C) {
+	data := []byte{1, 2, 3, 4}
+	slice := []byte{1, 2, 3, 4}
+	exp := []byte{1, 4}
+	res := DeleteFromByteSlice(data, slice)
+
+	c.Assert(res, checker.DeepEquals, exp)
+}
+
+*/
+func (s *BytesSuite) TestNumberToBytes(c *checker.C) {
+	// data1 := int(1)
+	// res1 := NumberToBytes(data1, 16)
+	// c.Check(res1, checker.Panics)
+
+	var data2 float64 = 3.141592653
+	exp2 := []byte{0xe9, 0x38}
+	res2 := NumberToBytes(data2, 16)
+	c.Assert(res2, checker.DeepEquals, exp2)
+}
+
+func (s *BytesSuite) TestBytesToNumber(c *checker.C) {
+	datasmall := []byte{0xe9, 0x38, 0xe9, 0x38}
+	datalarge := []byte{0xe9, 0x38, 0xe9, 0x38, 0xe9, 0x38, 0xe9, 0x38}
+
+	var expsmall uint64 = 0xe938e938
+	var explarge uint64 = 0x0
+
+	ressmall := BytesToNumber(datasmall)
+	reslarge := BytesToNumber(datalarge)
+
+	c.Assert(ressmall, checker.Equals, expsmall)
+	c.Assert(reslarge, checker.Equals, explarge)
+
+}
+
+func (s *BytesSuite) TestReadVarInt(c *checker.C) {
+	data8 := []byte{1, 2, 3, 4, 5, 6, 7, 8}
+	data4 := []byte{1, 2, 3, 4}
+	data2 := []byte{1, 2}
+	data1 := []byte{1}
+
+	exp8 := uint64(72623859790382856)
+	exp4 := uint64(16909060)
+	exp2 := uint64(258)
+	exp1 := uint64(1)
+
+	res8 := ReadVarInt(data8)
+	res4 := ReadVarInt(data4)
+	res2 := ReadVarInt(data2)
+	res1 := ReadVarInt(data1)
+
+	c.Assert(res8, checker.Equals, exp8)
+	c.Assert(res4, checker.Equals, exp4)
+	c.Assert(res2, checker.Equals, exp2)
+	c.Assert(res1, checker.Equals, exp1)
+}
+
+func (s *BytesSuite) TestBinaryLength(c *checker.C) {
+	data1 := 0
+	data2 := 920987656789
+
+	exp1 := 0
+	exp2 := 5
+
+	res1 := BinaryLength(data1)
+	res2 := BinaryLength(data2)
+
+	c.Assert(res1, checker.Equals, exp1)
+	c.Assert(res2, checker.Equals, exp2)
+}
+
+func (s *BytesSuite) TestCopyBytes(c *checker.C) {
+	data1 := []byte{1, 2, 3, 4}
+	exp1 := []byte{1, 2, 3, 4}
+	res1 := CopyBytes(data1)
+	c.Assert(res1, checker.DeepEquals, exp1)
+}
+
+func (s *BytesSuite) TestIsHex(c *checker.C) {
+	data1 := "a9e67e"
+	exp1 := false
+	res1 := IsHex(data1)
+	c.Assert(res1, checker.DeepEquals, exp1)
+
+	data2 := "0xa9e67e00"
+	exp2 := true
+	res2 := IsHex(data2)
+	c.Assert(res2, checker.DeepEquals, exp2)
+
+}
+
+func (s *BytesSuite) TestParseDataString(c *checker.C) {
+	res1 := ParseData("hello", "world", "0x0106")
+	data := "68656c6c6f000000000000000000000000000000000000000000000000000000776f726c640000000000000000000000000000000000000000000000000000000106000000000000000000000000000000000000000000000000000000000000"
+	exp1 := Hex2Bytes(data)
+	c.Assert(res1, checker.DeepEquals, exp1)
+}
+
+func (s *BytesSuite) TestParseDataBytes(c *checker.C) {
+	data1 := []byte{232, 212, 165, 16, 0}
+	exp1 := []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 232, 212, 165, 16, 0}
+
+	res1 := ParseData(data1)
+	c.Assert(res1, checker.DeepEquals, exp1)
+
+}
+
+func (s *BytesSuite) TestLeftPadBytes(c *checker.C) {
+	val1 := []byte{1, 2, 3, 4}
+	exp1 := []byte{0, 0, 0, 0, 1, 2, 3, 4}
+
+	res1 := LeftPadBytes(val1, 8)
+	res2 := LeftPadBytes(val1, 2)
+
+	c.Assert(res1, checker.DeepEquals, exp1)
+	c.Assert(res2, checker.DeepEquals, val1)
+}
+
+func (s *BytesSuite) TestFormatData(c *checker.C) {
+	data1 := ""
+	data2 := "0xa9e67e00"
+	data3 := "a9e67e"
+	data4 := "\"a9e67e00\""
+
+	// exp1 := []byte{}
+	exp2 := []byte{00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 0xa9, 0xe6, 0x7e, 00}
+	exp3 := []byte{00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00}
+	exp4 := []byte{0x61, 0x39, 0x65, 0x36, 0x37, 0x65, 0x30, 0x30, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00}
+
+	res1 := FormatData(data1)
+	res2 := FormatData(data2)
+	res3 := FormatData(data3)
+	res4 := FormatData(data4)
+
+	c.Assert(res1, checker.IsNil)
+	c.Assert(res2, checker.DeepEquals, exp2)
+	c.Assert(res3, checker.DeepEquals, exp3)
+	c.Assert(res4, checker.DeepEquals, exp4)
+}
+
+func (s *BytesSuite) TestRightPadBytes(c *checker.C) {
+	val := []byte{1, 2, 3, 4}
+	exp := []byte{1, 2, 3, 4, 0, 0, 0, 0}
+
+	resstd := RightPadBytes(val, 8)
+	resshrt := RightPadBytes(val, 2)
+
+	c.Assert(resstd, checker.DeepEquals, exp)
+	c.Assert(resshrt, checker.DeepEquals, val)
+}
+
+func (s *BytesSuite) TestLeftPadString(c *checker.C) {
+	val := "test"
+	exp := "\x30\x30\x30\x30" + val
+
+	resstd := LeftPadString(val, 8)
+	resshrt := LeftPadString(val, 2)
+
+	c.Assert(resstd, checker.Equals, exp)
+	c.Assert(resshrt, checker.Equals, val)
+}
+
+func (s *BytesSuite) TestRightPadString(c *checker.C) {
+	val := "test"
+	exp := val + "\x30\x30\x30\x30"
+
+	resstd := RightPadString(val, 8)
+	resshrt := RightPadString(val, 2)
+
+	c.Assert(resstd, checker.Equals, exp)
+	c.Assert(resshrt, checker.Equals, val)
 }
diff --git a/ethutil/common.go b/ethutil/common.go
index e60f237cf..0a29cac6c 100644
--- a/ethutil/common.go
+++ b/ethutil/common.go
@@ -66,6 +66,7 @@ func CurrencyToString(num *big.Int) string {
 		denom = "Ada"
 	}
 
+	// TODO add comment clarifying expected behavior
 	if len(fin.String()) > 5 {
 		return fmt.Sprintf("%sE%d %s", fin.String()[0:5], len(fin.String())-5, denom)
 	}
diff --git a/ethutil/common_test.go b/ethutil/common_test.go
index 2667eaf3a..056676765 100644
--- a/ethutil/common_test.go
+++ b/ethutil/common_test.go
@@ -2,18 +2,55 @@ package ethutil
 
 import (
 	"math/big"
+	"os"
 	"testing"
 )
 
+func TestOS(t *testing.T) {
+	res := IsWindows()
+
+	if res && (os.PathSeparator != '\\' || os.PathListSeparator != ';') {
+		t.Error("IsWindows is", res, "but path is", os.PathSeparator)
+	}
+
+	if !res && (os.PathSeparator == '\\' && os.PathListSeparator == ';') {
+		t.Error("IsWindows is", res, "but path is", os.PathSeparator)
+	}
+}
+
+func TestWindonziePath(t *testing.T) {
+	path := "/opt/eth/test/file.ext"
+	res := WindonizePath(path)
+	iswindowspath := os.PathSeparator == '\\'
+
+	if !iswindowspath && string(res[0]) != "/" {
+		t.Error("Got", res)
+	}
+
+	if iswindowspath && string(res[0]) == "/" {
+		t.Error("Got", res)
+	}
+}
+
 func TestCommon(t *testing.T) {
+	douglas := CurrencyToString(BigPow(10, 43))
+	einstein := CurrencyToString(BigPow(10, 22))
 	ether := CurrencyToString(BigPow(10, 19))
 	finney := CurrencyToString(BigPow(10, 16))
 	szabo := CurrencyToString(BigPow(10, 13))
-	vito := CurrencyToString(BigPow(10, 10))
-	turing := CurrencyToString(BigPow(10, 7))
-	eins := CurrencyToString(BigPow(10, 4))
+	shannon := CurrencyToString(BigPow(10, 10))
+	babbage := CurrencyToString(BigPow(10, 7))
+	ada := CurrencyToString(BigPow(10, 4))
 	wei := CurrencyToString(big.NewInt(10))
 
+	if douglas != "10 Douglas" {
+		t.Error("Got", douglas)
+	}
+
+	if einstein != "10 Einstein" {
+		t.Error("Got", einstein)
+	}
+
 	if ether != "10 Ether" {
 		t.Error("Got", ether)
 	}
@@ -26,19 +63,37 @@ func TestCommon(t *testing.T) {
 		t.Error("Got", szabo)
 	}
 
-	if vito != "10 Shannon" {
-		t.Error("Got", vito)
+	if shannon != "10 Shannon" {
+		t.Error("Got", shannon)
 	}
 
-	if turing != "10 Babbage" {
-		t.Error("Got", turing)
+	if babbage != "10 Babbage" {
+		t.Error("Got", babbage)
 	}
 
-	if eins != "10 Ada" {
-		t.Error("Got", eins)
+	if ada != "10 Ada" {
+		t.Error("Got", ada)
 	}
 
 	if wei != "10 Wei" {
 		t.Error("Got", wei)
 	}
 }
+
+func TestLarge(t *testing.T) {
+	douglaslarge := CurrencyToString(BigPow(100000000, 43))
+	adalarge := CurrencyToString(BigPow(100000000, 4))
+	weilarge := CurrencyToString(big.NewInt(100000000))
+
+	if douglaslarge != "10000E298 Douglas" {
+		t.Error("Got", douglaslarge)
+	}
+
+	if adalarge != "10000E7 Einstein" {
+		t.Error("Got", adalarge)
+	}
+
+	if weilarge != "100 Babbage" {
+		t.Error("Got", weilarge)
+	}
+}
diff --git a/ethutil/main_test.go b/ethutil/main_test.go
new file mode 100644
index 000000000..94f34677d
--- /dev/null
+++ b/ethutil/main_test.go
@@ -0,0 +1,8 @@
+package ethutil
+
+import (
+	checker "gopkg.in/check.v1"
+	"testing"
+)
+
+func Test(t *testing.T) { checker.TestingT(t) }
diff --git a/ethutil/path_test.go b/ethutil/path_test.go
new file mode 100644
index 000000000..908c94ee7
--- /dev/null
+++ b/ethutil/path_test.go
@@ -0,0 +1,51 @@
+package ethutil
+
+import (
+	// "os"
+	"testing"
+)
+
+func TestGoodFile(t *testing.T) {
+	goodpath := "~/goethereumtest.pass"
+	path := ExpandHomePath(goodpath)
+	contentstring := "3.14159265358979323846"
+
+	err := WriteFile(path, []byte(contentstring))
+	if err != nil {
+		t.Error("Could not write file")
+	}
+
+	if !FileExist(path) {
+		t.Error("File not found at", path)
+	}
+
+	v, err := ReadAllFile(path)
+	if err != nil {
+		t.Error("Could not read file", path)
+	}
+	if v != contentstring {
+		t.Error("Expected", contentstring, "Got", v)
+	}
+
+}
+
+func TestBadFile(t *testing.T) {
+	badpath := "/this/path/should/not/exist/goethereumtest.fail"
+	path := ExpandHomePath(badpath)
+	contentstring := "3.14159265358979323846"
+
+	err := WriteFile(path, []byte(contentstring))
+	if err == nil {
+		t.Error("Wrote file, but should not be able to", path)
+	}
+
+	if FileExist(path) {
+		t.Error("Found file, but should not be able to", path)
+	}
+
+	v, err := ReadAllFile(path)
+	if err == nil {
+		t.Error("Read file, but should not be able to", v)
+	}
+
+}
diff --git a/ethutil/rand_test.go b/ethutil/rand_test.go
new file mode 100644
index 000000000..c12698538
--- /dev/null
+++ b/ethutil/rand_test.go
@@ -0,0 +1,17 @@
+package ethutil
+
+import (
+	checker "gopkg.in/check.v1"
+)
+
+type RandomSuite struct{}
+
+var _ = checker.Suite(&RandomSuite{})
+
+func (s *RandomSuite) TestRandomUint64(c *checker.C) {
+	res1, _ := RandomUint64()
+	res2, _ := RandomUint64()
+	c.Assert(res1, checker.NotNil)
+	c.Assert(res2, checker.NotNil)
+	c.Assert(res1, checker.Not(checker.Equals), res2)
+}
diff --git a/ethutil/size_test.go b/ethutil/size_test.go
index 82aa1c653..e0f28abc5 100644
--- a/ethutil/size_test.go
+++ b/ethutil/size_test.go
@@ -1,12 +1,23 @@
 package ethutil
 
 import (
-	"fmt"
-	"testing"
+	checker "gopkg.in/check.v1"
 )
 
-func TestSize(t *testing.T) {
-	fmt.Println(StorageSize(2381273))
-	fmt.Println(StorageSize(2192))
-	fmt.Println(StorageSize(12))
+type SizeSuite struct{}
+
+var _ = checker.Suite(&SizeSuite{})
+
+func (s *SizeSuite) TestStorageSizeString(c *checker.C) {
+	data1 := 2381273
+	data2 := 2192
+	data3 := 12
+
+	exp1 := "2.38 mB"
+	exp2 := "2.19 kB"
+	exp3 := "12.00 B"
+
+	c.Assert(StorageSize(data1).String(), checker.Equals, exp1)
+	c.Assert(StorageSize(data2).String(), checker.Equals, exp2)
+	c.Assert(StorageSize(data3).String(), checker.Equals, exp3)
 }
diff --git a/ethutil/value_test.go b/ethutil/value_test.go
index 5452a0790..7c58d3b56 100644
--- a/ethutil/value_test.go
+++ b/ethutil/value_test.go
@@ -1,86 +1,69 @@
 package ethutil
 
 import (
-	"bytes"
-	"fmt"
+	checker "gopkg.in/check.v1"
 	"math/big"
-	"testing"
 )
 
-func TestValueCmp(t *testing.T) {
+type ValueSuite struct{}
+
+var _ = checker.Suite(&ValueSuite{})
+
+func (s *ValueSuite) TestValueCmp(c *checker.C) {
 	val1 := NewValue("hello")
 	val2 := NewValue("world")
-	if val1.Cmp(val2) {
-		t.Error("Expected values not to be equal")
-	}
+	c.Assert(val1.Cmp(val2), checker.Equals, false)
 
 	val3 := NewValue("hello")
 	val4 := NewValue("hello")
-	if !val3.Cmp(val4) {
-		t.Error("Expected values to be equal")
-	}
+	c.Assert(val3.Cmp(val4), checker.Equals, true)
 }
 
-func TestValueTypes(t *testing.T) {
+func (s *ValueSuite) TestValueTypes(c *checker.C) {
 	str := NewValue("str")
 	num := NewValue(1)
 	inter := NewValue([]interface{}{1})
 	byt := NewValue([]byte{1, 2, 3, 4})
 	bigInt := NewValue(big.NewInt(10))
 
-	if str.Str() != "str" {
-		t.Errorf("expected Str to return 'str', got %s", str.Str())
-	}
-
-	if num.Uint() != 1 {
-		t.Errorf("expected Uint to return '1', got %d", num.Uint())
-	}
-
+	strExp := "str"
+	numExp := uint64(1)
 	interExp := []interface{}{1}
-	if !NewValue(inter.Interface()).Cmp(NewValue(interExp)) {
-		t.Errorf("expected Interface to return '%v', got %v", interExp, num.Interface())
-	}
-
 	bytExp := []byte{1, 2, 3, 4}
-	if bytes.Compare(byt.Bytes(), bytExp) != 0 {
-		t.Errorf("expected Bytes to return '%v', got %v", bytExp, byt.Bytes())
-	}
-
 	bigExp := big.NewInt(10)
-	if bigInt.BigInt().Cmp(bigExp) != 0 {
-		t.Errorf("expected BigInt to return '%v', got %v", bigExp, bigInt.BigInt())
-	}
+
+	c.Assert(str.Str(), checker.Equals, strExp)
+	c.Assert(num.Uint(), checker.Equals, numExp)
+	c.Assert(NewValue(inter.Interface()).Cmp(NewValue(interExp)), checker.Equals, true)
+	c.Assert(byt.Bytes(), checker.DeepEquals, bytExp)
+	c.Assert(bigInt.BigInt(), checker.DeepEquals, bigExp)
 }
 
-func TestIterator(t *testing.T) {
+func (s *ValueSuite) TestIterator(c *checker.C) {
 	value := NewValue([]interface{}{1, 2, 3})
-	it := value.NewIterator()
+	iter := value.NewIterator()
 	values := []uint64{1, 2, 3}
 	i := 0
-	for it.Next() {
-		if values[i] != it.Value().Uint() {
-			t.Errorf("Expected %d, got %d", values[i], it.Value().Uint())
-		}
+	for iter.Next() {
+		c.Assert(values[i], checker.Equals, iter.Value().Uint())
 		i++
 	}
 }
 
-func TestMath(t *testing.T) {
-	a := NewValue(1)
-	a.Add(1).Add(1)
-
-	if !a.DeepCmp(NewValue(3)) {
-		t.Error("Expected 3, got", a)
-	}
+func (s *ValueSuite) TestMath(c *checker.C) {
+	data1 := NewValue(1)
+	data1.Add(1).Add(1)
+	exp1 := NewValue(3)
+	data2 := NewValue(2)
+	data2.Sub(1).Sub(1)
+	exp2 := NewValue(0)
 
-	a = NewValue(2)
-	a.Sub(1).Sub(1)
-	if !a.DeepCmp(NewValue(0)) {
-		t.Error("Expected 0, got", a)
-	}
+	c.Assert(data1.DeepCmp(exp1), checker.Equals, true)
+	c.Assert(data2.DeepCmp(exp2), checker.Equals, true)
 }
 
-func TestString(t *testing.T) {
-	a := NewValue("10")
-	fmt.Println("VALUE WITH STRING:", a.Int())
+func (s *ValueSuite) TestString(c *checker.C) {
+	data := "10"
+	exp := int64(10)
+	c.Assert(NewValue(data).Int(), checker.DeepEquals, exp)
 }
diff --git a/state/state_test.go b/state/state_test.go
index 737815e90..9dd965e95 100644
--- a/state/state_test.go
+++ b/state/state_test.go
@@ -1,6 +1,7 @@
 package state
 
 import (
+	. "gopkg.in/check.v1"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/ethdb"
@@ -8,29 +9,49 @@ import (
 	"github.com/ethereum/go-ethereum/trie"
 )
 
-var ZeroHash256 = make([]byte, 32)
+func Test(t *testing.T) { TestingT(t) }
 
-func TestSnapshot(t *testing.T) {
-	db, _ := ethdb.NewMemDatabase()
-	ethutil.ReadConfig(".ethtest", "/tmp/ethtest", "")
-	ethutil.Config.Db = db
-
-	state := New(trie.New(db, ""))
-
-	stateObject := state.GetOrNewStateObject([]byte("aa"))
+type StateSuite struct {
+	state *State
+}
 
-	stateObject.SetStorage(ethutil.Big("0"), ethutil.NewValue(42))
+var _ = Suite(&StateSuite{})
 
-	snapshot := state.Copy()
+const expectedasbytes = "Expected % x Got % x"
 
-	stateObject = state.GetStateObject([]byte("aa"))
-	stateObject.SetStorage(ethutil.Big("0"), ethutil.NewValue(43))
+// var ZeroHash256 = make([]byte, 32)
 
-	state.Set(snapshot)
+func (s *StateSuite) SetUpTest(c *C) {
+	db, _ := ethdb.NewMemDatabase()
+	ethutil.ReadConfig(".ethtest", "/tmp/ethtest", "")
+	ethutil.Config.Db = db
+	s.state = New(trie.New(db, ""))
+}
 
-	stateObject = state.GetStateObject([]byte("aa"))
-	res := stateObject.GetStorage(ethutil.Big("0"))
-	if !res.Cmp(ethutil.NewValue(42)) {
-		t.Error("Expected storage 0 to be 42", res)
-	}
+func (s *StateSuite) TestSnapshot(c *C) {
+	stateobjaddr := []byte("aa")
+	storageaddr := ethutil.Big("0")
+	data1 := ethutil.NewValue(42)
+	data2 := ethutil.NewValue(43)
+
+	// get state object
+	stateObject := s.state.GetOrNewStateObject(stateobjaddr)
+	// set inital state object value
+	stateObject.SetStorage(storageaddr, data1)
+	// get snapshot of current state
+	snapshot := s.state.Copy()
+
+	// get state object. is this strictly necessary?
+	stateObject = s.state.GetStateObject(stateobjaddr)
+	// set new state object value
+	stateObject.SetStorage(storageaddr, data2)
+	// restore snapshot
+	s.state.Set(snapshot)
+
+	// get state object
+	stateObject = s.state.GetStateObject(stateobjaddr)
+	// get state storage value
+	res := stateObject.GetStorage(storageaddr)
+
+	c.Assert(data1, DeepEquals, res, Commentf(expectedasbytes, data1, res))
 }