solidity compiler and contract metadocs integration

* common/compiler: solidity compiler + tests
* rpc: eth_compilers, eth_compileSolidity + tests
* fix natspec test using keystore API, notice exp dynamically changes addr, cleanup
* resolver implements registrars and needs to create reg contract (temp)
* xeth: solidity compiler. expose getter Solc() and paths setter SetSolc(solcPath)
* ethereumApi: implement compiler related RPC calls using XEth - json struct tests
* admin: make use of XEth.SetSolc to allow runtime setting of compiler paths
* cli: command line flags solc to set custom solc bin path
* js admin api with new features debug and contractInfo modules
* wiki is the doc https://github.com/ethereum/go-ethereum/wiki/Contracts-and-Transactions

7 files changed, 641 insertions, 369 deletions

diff --git a/common/compiler/solidity.go b/common/compiler/solidity.go
new file mode 100644
index 000000000..36d0e96cc
--- /dev/null
+++ b/common/compiler/solidity.go
@@ -0,0 +1,187 @@
+package compiler
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+)
+
+const (
+	flair           = "Christian <c@ethdev.com> and Lefteris <lefteris@ethdev.com> (c) 2014-2015"
+	languageVersion = "0"
+)
+
+var (
+	versionRegExp = regexp.MustCompile("[0-9]+.[0-9]+.[0-9]+")
+	params        = []string{
+		"--binary",       // Request to output the contract in binary (hexadecimal).
+		"file",           //
+		"--json-abi",     // Request to output the contract's JSON ABI interface.
+		"file",           //
+		"--natspec-user", // Request to output the contract's Natspec user documentation.
+		"file",           //
+		"--natspec-dev",  // Request to output the contract's Natspec developer documentation.
+		"file",
+	}
+)
+
+type Contract struct {
+	Code string       `json:"code"`
+	Info ContractInfo `json:"info"`
+}
+
+type ContractInfo struct {
+	Source          string      `json:"source"`
+	Language        string      `json:"language"`
+	LanguageVersion string      `json:"languageVersion"`
+	CompilerVersion string      `json:"compilerVersion"`
+	AbiDefinition   interface{} `json:"abiDefinition"`
+	UserDoc         interface{} `json:"userDoc"`
+	DeveloperDoc    interface{} `json:"developerDoc"`
+}
+
+type Solidity struct {
+	solcPath string
+	version  string
+}
+
+func New(solcPath string) (sol *Solidity, err error) {
+	// set default solc
+	if len(solcPath) == 0 {
+		solcPath = "solc"
+	}
+	solcPath, err = exec.LookPath(solcPath)
+	if err != nil {
+		return
+	}
+
+	cmd := exec.Command(solcPath, "--version")
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	err = cmd.Run()
+	if err != nil {
+		return
+	}
+
+	version := versionRegExp.FindString(out.String())
+	sol = &Solidity{
+		solcPath: solcPath,
+		version:  version,
+	}
+	glog.V(logger.Info).Infoln(sol.Info())
+	return
+}
+
+func (sol *Solidity) Info() string {
+	return fmt.Sprintf("solc v%s\nSolidity Compiler: %s\n%s", sol.version, sol.solcPath, flair)
+}
+
+func (sol *Solidity) Compile(source string) (contract *Contract, err error) {
+
+	if len(source) == 0 {
+		err = fmt.Errorf("empty source")
+		return
+	}
+
+	wd, err := ioutil.TempDir("", "solc")
+	if err != nil {
+		return
+	}
+	defer os.RemoveAll(wd)
+
+	in := strings.NewReader(source)
+	var out bytes.Buffer
+	// cwd set to temp dir
+	cmd := exec.Command(sol.solcPath, params...)
+	cmd.Dir = wd
+	cmd.Stdin = in
+	cmd.Stdout = &out
+	err = cmd.Run()
+	if err != nil {
+		err = fmt.Errorf("solc error: %v", err)
+		return
+	}
+
+	matches, _ := filepath.Glob(wd + "/*.binary")
+	if len(matches) < 1 {
+		err = fmt.Errorf("solc error: missing code output")
+		return
+	}
+	if len(matches) > 1 {
+		err = fmt.Errorf("multi-contract sources are not supported")
+		return
+	}
+	_, file := filepath.Split(matches[0])
+	base := strings.Split(file, ".")[0]
+
+	codeFile := path.Join(wd, base+".binary")
+	abiDefinitionFile := path.Join(wd, base+".abi")
+	userDocFile := path.Join(wd, base+".docuser")
+	developerDocFile := path.Join(wd, base+".docdev")
+
+	code, err := ioutil.ReadFile(codeFile)
+	if err != nil {
+		err = fmt.Errorf("error reading compiler output for code: %v", err)
+		return
+	}
+	abiDefinitionJson, err := ioutil.ReadFile(abiDefinitionFile)
+	if err != nil {
+		err = fmt.Errorf("error reading compiler output for abiDefinition: %v", err)
+		return
+	}
+	var abiDefinition interface{}
+	err = json.Unmarshal(abiDefinitionJson, &abiDefinition)
+
+	userDocJson, err := ioutil.ReadFile(userDocFile)
+	if err != nil {
+		err = fmt.Errorf("error reading compiler output for userDoc: %v", err)
+		return
+	}
+	var userDoc interface{}
+	err = json.Unmarshal(userDocJson, &userDoc)
+
+	developerDocJson, err := ioutil.ReadFile(developerDocFile)
+	if err != nil {
+		err = fmt.Errorf("error reading compiler output for developerDoc: %v", err)
+		return
+	}
+	var developerDoc interface{}
+	err = json.Unmarshal(developerDocJson, &developerDoc)
+
+	contract = &Contract{
+		Code: string(code),
+		Info: ContractInfo{
+			Source:          source,
+			Language:        "Solidity",
+			LanguageVersion: languageVersion,
+			CompilerVersion: sol.version,
+			AbiDefinition:   abiDefinition,
+			UserDoc:         userDoc,
+			DeveloperDoc:    developerDoc,
+		},
+	}
+
+	return
+}
+
+func ExtractInfo(contract *Contract, filename string) (contenthash common.Hash, err error) {
+	contractInfo, err := json.Marshal(contract.Info)
+	if err != nil {
+		return
+	}
+	contenthash = common.BytesToHash(crypto.Sha3(contractInfo))
+	err = ioutil.WriteFile(filename, contractInfo, 0600)
+	return
+}
diff --git a/common/compiler/solidity_test.go b/common/compiler/solidity_test.go
new file mode 100644
index 000000000..8fdcb6a99
--- /dev/null
+++ b/common/compiler/solidity_test.go
@@ -0,0 +1,89 @@
+package compiler
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+var (
+	source = `
+contract test {
+   /// @notice Will multiply ` + "`a`" + ` by 7.
+   function multiply(uint a) returns(uint d) {
+       return a * 7;
+   }
+}
+`
+	code = "605280600c6000396000f3006000357c010000000000000000000000000000000000000000000000000000000090048063c6888fa114602e57005b60376004356041565b8060005260206000f35b6000600782029050604d565b91905056"
+	info = `{"source":"\ncontract test {\n   /// @notice Will multiply ` + "`a`" + ` by 7.\n   function multiply(uint a) returns(uint d) {\n       return a * 7;\n   }\n}\n","language":"Solidity","languageVersion":"0","compilerVersion":"0.9.13","abiDefinition":[{"constant":false,"inputs":[{"name":"a","type":"uint256"}],"name":"multiply","outputs":[{"name":"d","type":"uint256"}],"type":"function"}],"userDoc":{"methods":{"multiply(uint256)":{"notice":"Will multiply ` + "`a`" + ` by 7."}}},"developerDoc":{"methods":{}}}`
+
+	infohash = common.HexToHash("0xfdb031637e8a1c1891143f8d129ebc7f7c4e4b41ecad8c85abe1756190f74204")
+)
+
+func TestCompiler(t *testing.T) {
+	sol, err := New("")
+	if err != nil {
+		t.Skip("no solc installed")
+	}
+	contract, err := sol.Compile(source)
+	if err != nil {
+		t.Errorf("error compiling source. result %v: %v", contract, err)
+		return
+	}
+	if contract.Code != code {
+		t.Errorf("wrong code, expected\n%s, got\n%s", code, contract.Code)
+	}
+}
+
+func TestCompileError(t *testing.T) {
+	sol, err := New("")
+	if err != nil {
+		t.Skip("no solc installed")
+	}
+	contract, err := sol.Compile(source[2:])
+	if err == nil {
+		t.Errorf("error expected compiling source. got none. result %v", contract)
+		return
+	}
+}
+
+func TestNoCompiler(t *testing.T) {
+	_, err := New("/path/to/solc")
+	if err != nil {
+		t.Log("solidity quits with error: %v", err)
+	} else {
+		t.Errorf("no solc installed, but got no error")
+	}
+}
+
+func TestExtractInfo(t *testing.T) {
+	var cinfo ContractInfo
+	err := json.Unmarshal([]byte(info), &cinfo)
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	contract := &Contract{
+		Code: "",
+		Info: cinfo,
+	}
+	filename := "/tmp/solctest.info.json"
+	os.Remove(filename)
+	cinfohash, err := ExtractInfo(contract, filename)
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	got, err := ioutil.ReadFile(filename)
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if string(got) != info {
+		t.Errorf("incorrect info.json extracted, expected:\n%s\ngot\n%s", info, string(got))
+	}
+	if cinfohash != infohash {
+		t.Errorf("content hash for info is incorrect. expected %v, got %v", infohash.Hex(), cinfohash.Hex())
+	}
+}
diff --git a/common/natspec/natspec.go b/common/natspec/natspec.go
index 38e7c1a9d..7e5f053c7 100644
--- a/common/natspec/natspec.go
+++ b/common/natspec/natspec.go
@@ -17,118 +17,119 @@ import (
 type abi2method map[[8]byte]*method
 
 type NatSpec struct {
-	jsvm                    *otto.Otto
-	userDocJson, abiDocJson []byte
-	userDoc                 userDoc
-	tx, data                string
-	// abiDoc abiDoc
-}
-
-func getFallbackNotice(comment, tx string) string {
-
-	return "About to submit transaction (" + comment + "): " + tx
-
+	jsvm       *otto.Otto
+	abiDocJson []byte
+	userDoc    userDoc
+	tx, data   string
 }
 
+// main entry point for to get natspec notice for a transaction
+// the implementation is frontend friendly in that it always gives back
+// a notice that is safe to display
+// :FIXME: the second return value is an error, which can be used to fine-tune bahaviour
 func GetNotice(xeth *xeth.XEth, tx string, http *docserver.DocServer) (notice string) {
-
 	ns, err := New(xeth, tx, http)
 	if err != nil {
 		if ns == nil {
-			return getFallbackNotice("no NatSpec info found for contract", tx)
+			return getFallbackNotice(fmt.Sprintf("no NatSpec info found for contract: %v", err), tx)
 		} else {
-			return getFallbackNotice("invalid NatSpec info", tx)
+			return getFallbackNotice(fmt.Sprintf("invalid NatSpec info: %v", err), tx)
 		}
 	}
 
-	notice, err2 := ns.Notice()
-
-	if err2 != nil {
-		return getFallbackNotice("NatSpec notice error \""+err2.Error()+"\"", tx)
+	notice, err = ns.Notice()
+	if err != nil {
+		return getFallbackNotice(fmt.Sprintf("NatSpec notice error: %v", err), tx)
 	}
 
 	return
+}
 
+func getFallbackNotice(comment, tx string) string {
+	return fmt.Sprintf("About to submit transaction (%s): %s", comment, tx)
 }
 
-func New(xeth *xeth.XEth, tx string, http *docserver.DocServer) (self *NatSpec, err error) {
+type transaction struct {
+	To   string `json:"to"`
+	Data string `json:"data"`
+}
 
-	// extract contract address from tx
+type jsonTx struct {
+	Params []transaction `json:"params"`
+}
+
+type contractInfo struct {
+	Source        string          `json:"source"`
+	Language      string          `json:"language"`
+	Version       string          `json:"compilerVersion"`
+	AbiDefinition json.RawMessage `json:"abiDefinition"`
+	UserDoc       userDoc         `json:"userDoc"`
+	DeveloperDoc  json.RawMessage `json:"developerDoc"`
+}
 
-	var obj map[string]json.RawMessage
-	err = json.Unmarshal([]byte(tx), &obj)
+func New(xeth *xeth.XEth, jsontx string, http *docserver.DocServer) (self *NatSpec, err error) {
+
+	// extract contract address from tx
+	var tx jsonTx
+	err = json.Unmarshal([]byte(jsontx), &tx)
 	if err != nil {
 		return
 	}
-	var tmp []map[string]string
-	err = json.Unmarshal(obj["params"], &tmp)
+	t := tx.Params[0]
+	contractAddress := t.To
+
+	content, err := FetchDocsForContract(contractAddress, xeth, http)
 	if err != nil {
 		return
 	}
-	contractAddress := tmp[0]["to"]
 
+	self, err = NewWithDocs(content, jsontx, t.Data)
+	return
+}
+
+// also called by admin.contractInfo.get
+func FetchDocsForContract(contractAddress string, xeth *xeth.XEth, http *docserver.DocServer) (content []byte, err error) {
 	// retrieve contract hash from state
-	if !xeth.IsContract(contractAddress) {
-		err = fmt.Errorf("NatSpec error: contract not found")
-		return
-	}
 	codehex := xeth.CodeAt(contractAddress)
-	codeHash := common.BytesToHash(crypto.Sha3(common.Hex2Bytes(codehex[2:])))
-	// parse out host/domain
+	codeb := xeth.CodeAtBytes(contractAddress)
 
+	if codehex == "0x" {
+		err = fmt.Errorf("contract (%v) not found", contractAddress)
+		return
+	}
+	codehash := common.BytesToHash(crypto.Sha3(codeb))
 	// set up nameresolver with natspecreg + urlhint contract addresses
-	res := resolver.New(
-		xeth,
-		resolver.URLHintContractAddress,
-		resolver.HashRegContractAddress,
-	)
+	res := resolver.New(xeth)
 
 	// resolve host via HashReg/UrlHint Resolver
-	uri, hash, err := res.KeyToUrl(codeHash)
+	uri, hash, err := res.KeyToUrl(codehash)
 	if err != nil {
 		return
 	}
 
 	// get content via http client and authenticate content using hash
-	content, err := http.GetAuthContent(uri, hash)
-	if err != nil {
-		return
-	}
-
-	// get abi, userdoc
-	var obj2 map[string]json.RawMessage
-	err = json.Unmarshal(content, &obj2)
+	content, err = http.GetAuthContent(uri, hash)
 	if err != nil {
 		return
 	}
 
-	abi := []byte(obj2["abi"])
-	userdoc := []byte(obj2["userdoc"])
-
-	self, err = NewWithDocs(abi, userdoc, tx)
 	return
 }
 
-func NewWithDocs(abiDocJson, userDocJson []byte, tx string) (self *NatSpec, err error) {
+func NewWithDocs(infoDoc []byte, tx string, data string) (self *NatSpec, err error) {
 
-	var obj map[string]json.RawMessage
-	err = json.Unmarshal([]byte(tx), &obj)
+	var contract contractInfo
+	err = json.Unmarshal(infoDoc, &contract)
 	if err != nil {
 		return
 	}
-	var tmp []map[string]string
-	err = json.Unmarshal(obj["params"], &tmp)
-	if err != nil {
-		return
-	}
-	data := tmp[0]["data"]
 
 	self = &NatSpec{
-		jsvm:        otto.New(),
-		abiDocJson:  abiDocJson,
-		userDocJson: userDocJson,
-		tx:          tx,
-		data:        data,
+		jsvm:       otto.New(),
+		abiDocJson: []byte(contract.AbiDefinition),
+		userDoc:    contract.UserDoc,
+		tx:         tx,
+		data:       data,
 	}
 
 	// load and require natspec js (but it is meant to be protected environment)
@@ -137,13 +138,6 @@ func NewWithDocs(abiDocJson, userDocJson []byte, tx string) (self *NatSpec, err
 		return
 	}
 	_, err = self.jsvm.Run("var natspec = require('natspec');")
-	if err != nil {
-		return
-	}
-
-	err = json.Unmarshal(userDocJson, &self.userDoc)
-	// err = parseAbiJson(abiDocJson, &self.abiDoc)
-
 	return
 }
 
diff --git a/common/natspec/natspec_e2e_test.go b/common/natspec/natspec_e2e_test.go
index e54b9ee96..f9b0c1dcc 100644
--- a/common/natspec/natspec_e2e_test.go
+++ b/common/natspec/natspec_e2e_test.go
@@ -1,8 +1,8 @@
 package natspec
 
 import (
+	"fmt"
 	"io/ioutil"
-	"math/big"
 	"os"
 	"testing"
 
@@ -14,39 +14,26 @@ import (
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth"
-	"github.com/ethereum/go-ethereum/rpc"
 	xe "github.com/ethereum/go-ethereum/xeth"
 )
 
-type testFrontend struct {
-	t           *testing.T
-	ethereum    *eth.Ethereum
-	xeth        *xe.XEth
-	api         *rpc.EthereumApi
-	coinbase    string
-	stateDb     *state.StateDB
-	txc         uint64
-	lastConfirm string
-	makeNatSpec bool
-}
-
 const (
-	testAccount = "e273f01c99144c438695e10f24926dc1f9fbf62d"
-	testBalance = "1000000000000"
-)
+	testBalance = "10000000000000000000"
 
-const testFileName = "long_file_name_for_testing_registration_of_URLs_longer_than_32_bytes.content"
+	testFileName = "long_file_name_for_testing_registration_of_URLs_longer_than_32_bytes.content"
 
-const testNotice = "Register key `utils.toHex(_key)` <- content `utils.toHex(_content)`"
-const testExpNotice = "Register key 0xadd1a7d961cff0242089674ec2ef6fca671ab15e1fe80e38859fc815b98d88ab <- content 0xc00d5bcc872e17813df6ec5c646bb281a6e2d3b454c2c400c78192adf3344af9"
-const testExpNotice2 = `About to submit transaction (NatSpec notice error "abi key does not match any method"): {"id":6,"jsonrpc":"2.0","method":"eth_transact","params":[{"from":"0xe273f01c99144c438695e10f24926dc1f9fbf62d","to":"0xb737b91f8e95cf756766fc7c62c9a8ff58470381","value":"100000000000","gas":"100000","gasPrice":"100000","data":"0x31e12c20"}]}`
-const testExpNotice3 = `About to submit transaction (no NatSpec info found for contract): {"id":6,"jsonrpc":"2.0","method":"eth_transact","params":[{"from":"0xe273f01c99144c438695e10f24926dc1f9fbf62d","to":"0x8b839ad85686967a4f418eccc81962eaee314ac3","value":"100000000000","gas":"100000","gasPrice":"100000","data":"0x300a3bbfc00d5bcc872e17813df6ec5c646bb281a6e2d3b454c2c400c78192adf3344af900000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000000"}]}`
+	testNotice = "Register key `utils.toHex(_key)` <- content `utils.toHex(_content)`"
 
-const testUserDoc = `
+	testExpNotice = "Register key 0xadd1a7d961cff0242089674ec2ef6fca671ab15e1fe80e38859fc815b98d88ab <- content 0xb3a2dea218de5d8bbe6c4645aadbf67b5ab00ecb1a9ec95dbdad6a0eed3e41a7"
+
+	testExpNotice2 = `About to submit transaction (NatSpec notice error: abi key does not match any method): {"params":[{"to":"%s","data": "0x31e12c20"}]}`
+
+	testExpNotice3 = `About to submit transaction (no NatSpec info found for contract: content hash not found for '0x1392c62d05b2d149e22a339c531157ae06b44d39a674cce500064b12b9aeb019'): {"params":[{"to":"%s","data": "0x300a3bbfb3a2dea218de5d8bbe6c4645aadbf67b5ab00ecb1a9ec95dbdad6a0eed3e41a7000000000000000000000000000000000000000000000000000000000000000000000000000000000000000066696c653a2f2f2f746573742e636f6e74656e74"}]}`
+)
+
+const (
+	testUserDoc = `
 {
-  "source": "...",
-  "language": "Solidity",
-  "languageVersion": 1,
   "methods": {
     "register(uint256,uint256)": {
       "notice":  "` + testNotice + `"
@@ -60,8 +47,7 @@ const testUserDoc = `
   ]
 }
 `
-
-const testABI = `
+	testAbiDefinition = `
 [{
   "name": "register",
   "constant": false,
@@ -77,70 +63,81 @@ const testABI = `
 }]
 `
 
-const testDocs = `
+	testContractInfo = `
 {
-	"userdoc": ` + testUserDoc + `,
-	"abi": ` + testABI + `
+	"userDoc": ` + testUserDoc + `,
+	"abiDefinition": ` + testAbiDefinition + `
 }
 `
+)
+
+type testFrontend struct {
+	t *testing.T
+	// resolver    *resolver.Resolver
+	ethereum    *eth.Ethereum
+	xeth        *xe.XEth
+	coinbase    common.Address
+	stateDb     *state.StateDB
+	txc         uint64
+	lastConfirm string
+	wantNatSpec bool
+}
 
-func (f *testFrontend) UnlockAccount(acc []byte) bool {
-	f.t.Logf("Unlocking account %v\n", common.Bytes2Hex(acc))
-	f.ethereum.AccountManager().Unlock(acc, "password")
+func (self *testFrontend) UnlockAccount(acc []byte) bool {
+	self.ethereum.AccountManager().Unlock(acc, "password")
 	return true
 }
 
-func (f *testFrontend) ConfirmTransaction(tx string) bool {
-	//f.t.Logf("ConfirmTransaction called  tx = %v", tx)
-	if f.makeNatSpec {
+func (self *testFrontend) ConfirmTransaction(tx string) bool {
+	if self.wantNatSpec {
 		ds, err := docserver.New("/tmp/")
 		if err != nil {
-			f.t.Errorf("Error creating DocServer: %v", err)
+			self.t.Errorf("Error creating DocServer: %v", err)
 		}
-		f.lastConfirm = GetNotice(f.xeth, tx, ds)
+		self.lastConfirm = GetNotice(self.xeth, tx, ds)
 	}
 	return true
 }
 
-var port = 30300
-
 func testEth(t *testing.T) (ethereum *eth.Ethereum, err error) {
+
 	os.RemoveAll("/tmp/eth-natspec/")
-	err = os.MkdirAll("/tmp/eth-natspec/keys/e273f01c99144c438695e10f24926dc1f9fbf62d/", os.ModePerm)
+
+	err = os.MkdirAll("/tmp/eth-natspec/keys", os.ModePerm)
 	if err != nil {
-		t.Errorf("%v", err)
-		return
+		panic(err)
 	}
-	err = os.MkdirAll("/tmp/eth-natspec/data", os.ModePerm)
+
+	// create a testAddress
+	ks := crypto.NewKeyStorePassphrase("/tmp/eth-natspec/keys")
+	am := accounts.NewManager(ks)
+	testAccount, err := am.NewAccount("password")
 	if err != nil {
-		t.Errorf("%v", err)
-		return
+		panic(err)
 	}
-	ks := crypto.NewKeyStorePlain("/tmp/eth-natspec/keys")
-	ioutil.WriteFile("/tmp/eth-natspec/keys/e273f01c99144c438695e10f24926dc1f9fbf62d/e273f01c99144c438695e10f24926dc1f9fbf62d",
-		[]byte(`{"Id":"RhRXD+fNRKS4jx+7ZfEsNA==","Address":"4nPwHJkUTEOGleEPJJJtwfn79i0=","PrivateKey":"h4ACVpe74uIvi5Cg/2tX/Yrm2xdr3J7QoMbMtNX2CNc="}`), os.ModePerm)
+	testAddress := common.Bytes2Hex(testAccount.Address)
+
+	// set up mock genesis with balance on the testAddress
+	core.GenesisData = []byte(`{
+	"` + testAddress + `": {"balance": "` + testBalance + `"}
+	}`)
 
-	port++
+	// only use minimalistic stack with no networking
 	ethereum, err = eth.New(&eth.Config{
 		DataDir:        "/tmp/eth-natspec",
-		AccountManager: accounts.NewManager(ks),
-		Name:           "test",
+		AccountManager: am,
+		MaxPeers:       0,
 	})
 
 	if err != nil {
-		t.Errorf("%v", err)
-		return
+		panic(err)
 	}
 
 	return
 }
 
 func testInit(t *testing.T) (self *testFrontend) {
-
-	core.GenesisData = []byte(`{
-	"` + testAccount + `": {"balance": "` + testBalance + `"}
-	}`)
-
+	// initialise and start minimal ethereum stack
 	ethereum, err := testEth(t)
 	if err != nil {
 		t.Errorf("error creating ethereum: %v", err)
@@ -152,190 +149,95 @@ func testInit(t *testing.T) (self *testFrontend) {
 		return
 	}
 
+	// mock frontend
 	self = &testFrontend{t: t, ethereum: ethereum}
 	self.xeth = xe.New(ethereum, self)
-	self.api = rpc.NewEthereumApi(self.xeth)
 
-	addr := self.xeth.Coinbase()
+	addr, _ := ethereum.Etherbase()
 	self.coinbase = addr
-	if addr != "0x"+testAccount {
-		t.Errorf("CoinBase %v does not match TestAccount 0x%v", addr, testAccount)
-	}
-	t.Logf("CoinBase is %v", addr)
-
-	balance := self.xeth.BalanceAt(testAccount)
-	/*if balance != core.TestBalance {
-		t.Errorf("Balance %v does not match TestBalance %v", balance, core.TestBalance)
-	}*/
-	t.Logf("Balance is %v", balance)
-
 	self.stateDb = self.ethereum.ChainManager().State().Copy()
 
-	return
-
-}
-
-func (self *testFrontend) insertTx(addr, contract, fnsig string, args []string) {
-
-	//cb := common.HexToAddress(self.coinbase)
-	//coinbase := self.ethereum.ChainManager().State().GetStateObject(cb)
+	// initialise the registry contracts
+	// self.resolver.CreateContracts(addr)
+	resolver.New(self.xeth).CreateContracts(addr)
+	self.applyTxs()
+	// t.Logf("HashReg contract registered at %v", resolver.HashRegContractAddress)
+	// t.Logf("URLHint contract registered at %v", resolver.UrlHintContractAddress)
 
-	hash := common.Bytes2Hex(crypto.Sha3([]byte(fnsig)))
-	data := "0x" + hash[0:8]
-	for _, arg := range args {
-		data = data + common.Bytes2Hex(common.Hex2BytesFixed(arg, 32))
-	}
-	self.t.Logf("Tx data: %v", data)
-
-	jsontx := `
-[{
-	  "from": "` + addr + `",
-      "to": "` + contract + `",
-	  "value": "100000000000",
-	  "gas": "100000",
-	  "gasPrice": "100000",
-      "data": "` + data + `"
-}]
-`
-	req := &rpc.RpcRequest{
-		Jsonrpc: "2.0",
-		Method:  "eth_transact",
-		Params:  []byte(jsontx),
-		Id:      6,
-	}
-
-	var reply interface{}
-	err0 := self.api.GetRequestReply(req, &reply)
-	if err0 != nil {
-		self.t.Errorf("GetRequestReply error: %v", err0)
-	}
-
-	//self.xeth.Transact(addr, contract, "100000000000", "100000", "100000", data)
+	return
 
 }
 
+// this is needed for transaction to be applied to the state in testing
+// the heavy lifing is done in XEth.ApplyTestTxs
+// this is fragile,
+// and does process leaking since xeth loops cannot quit safely
+// should be replaced by proper mining with testDAG for easy full integration tests
 func (self *testFrontend) applyTxs() {
-
-	cb := common.HexToAddress(self.coinbase)
-	block := self.ethereum.ChainManager().NewBlock(cb)
-	coinbase := self.stateDb.GetStateObject(cb)
-	coinbase.SetGasPool(big.NewInt(10000000))
-	txs := self.ethereum.TxPool().GetQueuedTransactions()
-
-	for i := 0; i < len(txs); i++ {
-		for _, tx := range txs {
-			//self.t.Logf("%v %v %v", i, tx.Nonce(), self.txc)
-			if tx.Nonce() == self.txc {
-				_, gas, err := core.ApplyMessage(core.NewEnv(self.stateDb, self.ethereum.ChainManager(), tx, block), tx, coinbase)
-				//self.ethereum.TxPool().RemoveSet([]*types.Transaction{tx})
-				self.t.Logf("ApplyMessage: gas %v  err %v", gas, err)
-				self.txc++
-			}
-		}
-	}
-
-	//self.ethereum.TxPool().RemoveSet(txs)
-	self.xeth = self.xeth.WithState(self.stateDb)
-
-}
-
-func (self *testFrontend) registerURL(hash common.Hash, url string) {
-	hashHex := common.Bytes2Hex(hash[:])
-	urlBytes := []byte(url)
-	var bb bool = true
-	var cnt byte
-	for bb {
-		bb = len(urlBytes) > 0
-		urlb := urlBytes
-		if len(urlb) > 32 {
-			urlb = urlb[:32]
-		}
-		urlHex := common.Bytes2Hex(urlb)
-		self.insertTx(self.coinbase, resolver.URLHintContractAddress, "register(uint256,uint8,uint256)", []string{hashHex, common.Bytes2Hex([]byte{cnt}), urlHex})
-		if len(urlBytes) > 32 {
-			urlBytes = urlBytes[32:]
-		} else {
-			urlBytes = nil
-		}
-		cnt++
-	}
-}
-
-func (self *testFrontend) setOwner() {
-
-	self.insertTx(self.coinbase, resolver.HashRegContractAddress, "setowner()", []string{})
-
-	/*owner := self.xeth.StorageAt("0x"+resolver.HashRegContractAddress, "0x0000000000000000000000000000000000000000000000000000000000000000")
-	self.t.Logf("owner = %v", owner)
-	if owner != self.coinbase {
-		self.t.Errorf("setowner() unsuccessful, owner != coinbase")
-	}*/
-}
-
-func (self *testFrontend) registerNatSpec(codehash, dochash common.Hash) {
-
-	codeHex := common.Bytes2Hex(codehash[:])
-	docHex := common.Bytes2Hex(dochash[:])
-	self.insertTx(self.coinbase, resolver.HashRegContractAddress, "register(uint256,uint256)", []string{codeHex, docHex})
-}
-
-func (self *testFrontend) testResolver() *resolver.Resolver {
-	return resolver.New(self.xeth, resolver.URLHintContractAddress, resolver.HashRegContractAddress)
+	self.txc, self.xeth = self.xeth.ApplyTestTxs(self.stateDb, self.coinbase, self.txc)
+	return
 }
 
+// end to end test
 func TestNatspecE2E(t *testing.T) {
-	t.Skip()
+	// t.Skip()
 
 	tf := testInit(t)
 	defer tf.ethereum.Stop()
 
-	resolver.CreateContracts(tf.xeth, testAccount)
-	t.Logf("URLHint contract registered at %v", resolver.URLHintContractAddress)
-	t.Logf("HashReg contract registered at %v", resolver.HashRegContractAddress)
-	tf.applyTxs()
-
-	ioutil.WriteFile("/tmp/"+testFileName, []byte(testDocs), os.ModePerm)
-	dochash := common.BytesToHash(crypto.Sha3([]byte(testDocs)))
+	// create a contractInfo file (mock cloud-deployed contract metadocs)
+	// incidentally this is the info for the registry contract itself
+	ioutil.WriteFile("/tmp/"+testFileName, []byte(testContractInfo), os.ModePerm)
+	dochash := common.BytesToHash(crypto.Sha3([]byte(testContractInfo)))
 
-	codehex := tf.xeth.CodeAt(resolver.HashRegContractAddress)
-	codehash := common.BytesToHash(crypto.Sha3(common.Hex2Bytes(codehex[2:])))
+	// take the codehash for the contract we wanna test
+	// codehex := tf.xeth.CodeAt(resolver.HashRegContractAddress)
+	codeb := tf.xeth.CodeAtBytes(resolver.HashRegContractAddress)
+	codehash := common.BytesToHash(crypto.Sha3(codeb))
 
-	tf.setOwner()
-	tf.registerNatSpec(codehash, dochash)
-	tf.registerURL(dochash, "file:///"+testFileName)
-	tf.applyTxs()
-
-	chash, err := tf.testResolver().KeyToContentHash(codehash)
+	// use resolver to register codehash->dochash->url
+	registry := resolver.New(tf.xeth)
+	_, err := registry.Register(tf.coinbase, codehash, dochash, "file:///"+testFileName)
 	if err != nil {
-		t.Errorf("Can't find content hash")
-	}
-	t.Logf("chash = %x  err = %v", chash, err)
-	url, err2 := tf.testResolver().ContentHashToUrl(dochash)
-	if err2 != nil {
-		t.Errorf("Can't find URL hint")
+		t.Errorf("error registering: %v", err)
 	}
-	t.Logf("url = %v  err = %v", url, err2)
+	// apply txs to the state
+	tf.applyTxs()
 
 	// NatSpec info for register method of HashReg contract installed
 	// now using the same transactions to check confirm messages
 
-	tf.makeNatSpec = true
-	tf.registerNatSpec(codehash, dochash)
-	t.Logf("Confirm message: %v\n", tf.lastConfirm)
+	tf.wantNatSpec = true // this is set so now the backend uses natspec confirmation
+	_, err = registry.RegisterContentHash(tf.coinbase, codehash, dochash)
+	if err != nil {
+		t.Errorf("error calling contract registry: %v", err)
+	}
+
 	if tf.lastConfirm != testExpNotice {
-		t.Errorf("Wrong confirm message, expected '%v', got '%v'", testExpNotice, tf.lastConfirm)
+		t.Errorf("Wrong confirm message. expected '%v', got '%v'", testExpNotice, tf.lastConfirm)
 	}
 
-	tf.setOwner()
-	t.Logf("Confirm message for unknown method: %v\n", tf.lastConfirm)
-	if tf.lastConfirm != testExpNotice2 {
-		t.Errorf("Wrong confirm message, expected '%v', got '%v'", testExpNotice2, tf.lastConfirm)
+	// test unknown method
+	exp := fmt.Sprintf(testExpNotice2, resolver.HashRegContractAddress)
+	_, err = registry.SetOwner(tf.coinbase)
+	if err != nil {
+		t.Errorf("error setting owner: %v", err)
+	}
+
+	if tf.lastConfirm != exp {
+		t.Errorf("Wrong confirm message, expected '%v', got '%v'", exp, tf.lastConfirm)
+	}
+
+	// test unknown contract
+	exp = fmt.Sprintf(testExpNotice3, resolver.UrlHintContractAddress)
+
+	_, err = registry.RegisterUrl(tf.coinbase, dochash, "file:///test.content")
+	if err != nil {
+		t.Errorf("error registering: %v", err)
 	}
 
-	tf.registerURL(dochash, "file:///test.content")
-	t.Logf("Confirm message for unknown contract: %v\n", tf.lastConfirm)
-	if tf.lastConfirm != testExpNotice3 {
-		t.Errorf("Wrong confirm message, expected '%v', got '%v'", testExpNotice3, tf.lastConfirm)
+	if tf.lastConfirm != exp {
+		t.Errorf("Wrong confirm message, expected '%v', got '%v'", exp, tf.lastConfirm)
 	}
 
 }
diff --git a/common/natspec/natspec_test.go b/common/natspec/natspec_test.go
index 35a59469a..05df9e750 100644
--- a/common/natspec/natspec_test.go
+++ b/common/natspec/natspec_test.go
@@ -4,70 +4,65 @@ import (
 	"testing"
 )
 
-func makeUserdoc(desc string) []byte {
+func makeInfoDoc(desc string) []byte {
 	return []byte(`
 {
-  "source": "...",
+  "source": "contract test { }",
   "language": "Solidity",
-  "languageVersion": 1,
-  "methods": {
-    "multiply(uint256)": {
-      "notice":  "` + desc + `"
+  "compilerVersion": "1",
+  "userDoc": {
+    "methods": {
+      "multiply(uint256)": {
+        "notice":  "` + desc + `"
+      },
+      "balance(address)": {
+        "notice": "` + "`(balanceInmGAV / 1000).fixed(0,3)`" + ` GAV is the total funds available to ` + "`who.address()`." + `"
+      }
     },
-    "balance(address)": {
-      "notice": "` + "`(balanceInmGAV / 1000).fixed(0,3)`" + ` GAV is the total funds available to ` + "`who.address()`." + `"
-    }
+    "invariants": [
+      { "notice": "The sum total amount of GAV in the system is 1 million." }
+    ],
+    "construction": [
+      { "notice": "Endows ` + "`message.caller.address()`" + ` with 1m GAV." }
+    ]
   },
-  "invariants": [
-    { "notice": "The sum total amount of GAV in the system is 1 million." }
-  ],
-  "construction": [
-    { "notice": "Endows ` + "`message.caller.address()`" + ` with 1m GAV." }
-  ]
-}
-`)
+  "abiDefinition": [{
+    "name": "multiply",
+    "constant": false,
+    "type": "function",
+    "inputs": [{
+      "name": "a",
+      "type": "uint256"
+    }],
+    "outputs": [{
+      "name": "d",
+      "type": "uint256"
+    }]
+  }]
+}`)
 }
 
 var data = "0xc6888fa1000000000000000000000000000000000000000000000000000000000000007a"
 
 var tx = `
 {
-  "jsonrpc": "2.0",
-  "method": "eth_call",
   "params": [{
       "to": "0x8521742d3f456bd237e312d6e30724960f72517a",
       "data": "0xc6888fa1000000000000000000000000000000000000000000000000000000000000007a"
   }],
-  "id": 6
 }
 `
 
-var abi = []byte(`
-[{
-  "name": "multiply",
-  "constant": false,
-  "type": "function",
-  "inputs": [{
-    "name": "a",
-    "type": "uint256"
-  }],
-  "outputs": [{
-    "name": "d",
-    "type": "uint256"
-  }]
-}]
-`)
-
 func TestNotice(t *testing.T) {
 
 	desc := "Will multiply `a` by 7 and return `a * 7`."
 	expected := "Will multiply 122 by 7 and return 854."
 
-	userdoc := makeUserdoc(desc)
-
-	ns, err := NewWithDocs(abi, userdoc, tx)
+	infodoc := makeInfoDoc(desc)
+	ns, err := NewWithDocs(infodoc, tx, data)
 	if err != nil {
 		t.Errorf("New: error: %v", err)
+		return
 	}
 
 	notice, err := ns.Notice()
@@ -78,8 +73,6 @@ func TestNotice(t *testing.T) {
 
 	if notice != expected {
 		t.Errorf("incorrect notice. expected %v, got %v", expected, notice)
-	} else {
-		t.Logf("returned notice \"%v\"", notice)
 	}
 }
 
@@ -87,10 +80,10 @@ func TestNotice(t *testing.T) {
 func TestMissingMethod(t *testing.T) {
 
 	desc := "Will multiply `a` by 7 and return `a * 7`."
-	userdoc := makeUserdoc(desc)
 	expected := "natspec.js error evaluating expression: Natspec evaluation failed, method does not exist"
 
-	ns, err := NewWithDocs(abi, userdoc, tx)
+	infodoc := makeInfoDoc(desc)
+	ns, err := NewWithDocs(infodoc, tx, data)
 	if err != nil {
 		t.Errorf("New: error: %v", err)
 	}
@@ -113,9 +106,8 @@ func TestInvalidDesc(t *testing.T) {
 	desc := "Will multiply 122 by \"7\" and return 854."
 	expected := "invalid character '7' after object key:value pair"
 
-	userdoc := makeUserdoc(desc)
-
-	_, err := NewWithDocs(abi, userdoc, tx)
+	infodoc := makeInfoDoc(desc)
+	_, err := NewWithDocs(infodoc, tx, data)
 	if err == nil {
 		t.Errorf("expected error, got nothing", err)
 	} else {
@@ -131,9 +123,8 @@ func TestWrongInputParams(t *testing.T) {
 	desc := "Will multiply `e` by 7 and return `a * 7`."
 	expected := "natspec.js error evaluating expression: Natspec evaluation failed, wrong input params"
 
-	userdoc := makeUserdoc(desc)
-
-	ns, err := NewWithDocs(abi, userdoc, tx)
+	infodoc := makeInfoDoc(desc)
+	ns, err := NewWithDocs(infodoc, tx, data)
 	if err != nil {
 		t.Errorf("New: error: %v", err)
 	}
diff --git a/common/resolver/resolver.go b/common/resolver/resolver.go
index 42348a89c..9016547e1 100644
--- a/common/resolver/resolver.go
+++ b/common/resolver/resolver.go
@@ -6,7 +6,8 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
-	xe "github.com/ethereum/go-ethereum/xeth"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
 )
 
 /*
@@ -18,50 +19,152 @@ The resolver is meant to be called by the roundtripper transport implementation
 of a url scheme
 */
 
-// contract addresses will be hardcoded after they're created
-var URLHintContractAddress string = "0000000000000000000000000000000000000000000000000000000000001234"
-var HashRegContractAddress string = "0000000000000000000000000000000000000000000000000000000000005678"
+// // contract addresses will be hardcoded after they're created
+var UrlHintContractAddress, HashRegContractAddress string
 
-func CreateContracts(xeth *xe.XEth, addr string) {
-	var err error
-	URLHintContractAddress, err = xeth.Transact(addr, "", "", "100000000000", "1000000", "100000", ContractCodeURLhint)
+const (
+	txValue    = "0"
+	txGas      = "100000"
+	txGasPrice = "1000000000000"
+)
+
+func abi(s string) string {
+	return common.ToHex(crypto.Sha3([]byte(s))[:4])
+}
+
+var (
+	registerContentHashAbi = abi("register(uint256,uint256)")
+	registerUrlAbi         = abi("register(uint256,uint8,uint256)")
+	setOwnerAbi            = abi("setowner()")
+)
+
+type Backend interface {
+	StorageAt(string, string) string
+	Transact(fromStr, toStr, nonceStr, valueStr, gasStr, gasPriceStr, codeStr string) (string, error)
+}
+
+type Resolver struct {
+	backend Backend
+}
+
+func New(eth Backend) *Resolver {
+	return &Resolver{eth}
+}
+
+// for testing and play temporarily
+// ideally the HashReg and UrlHint contracts should be in the genesis block
+// if we got build-in support for natspec/contract info
+// there should be only one of these officially endorsed
+// addresses as constants
+// TODO: could get around this with namereg, check
+func (self *Resolver) CreateContracts(addr common.Address) (err error) {
+	HashRegContractAddress, err = self.backend.Transact(addr.Hex(), "", "", txValue, txGas, txGasPrice, ContractCodeHashReg)
 	if err != nil {
-		panic(err)
+		return
 	}
-	HashRegContractAddress, err = xeth.Transact(addr, "", "", "100000000000", "1000000", "100000", ContractCodeHashReg)
+	UrlHintContractAddress, err = self.backend.Transact(addr.Hex(), "", "", txValue, txGas, txGasPrice, ContractCodeURLhint)
+	glog.V(logger.Detail).Infof("HashReg @ %v\nUrlHint @ %v\n", HashRegContractAddress, UrlHintContractAddress)
+	return
+}
+
+// called as first step in the registration process on HashReg
+func (self *Resolver) SetOwner(address common.Address) (txh string, err error) {
+	return self.backend.Transact(
+		address.Hex(),
+		HashRegContractAddress,
+		"", txValue, txGas, txGasPrice,
+		setOwnerAbi,
+	)
+}
+
+// registers some content hash to a key/code hash
+// e.g., the contract Info combined Json Doc's ContentHash
+// to CodeHash of a contract or hash of a domain
+// kept
+func (self *Resolver) RegisterContentHash(address common.Address, codehash, dochash common.Hash) (txh string, err error) {
+	_, err = self.SetOwner(address)
 	if err != nil {
-		panic(err)
+		return
 	}
+	codehex := common.Bytes2Hex(codehash[:])
+	dochex := common.Bytes2Hex(dochash[:])
+
+	data := registerContentHashAbi + codehex + dochex
+	return self.backend.Transact(
+		address.Hex(),
+		HashRegContractAddress,
+		"", txValue, txGas, txGasPrice,
+		data,
+	)
 }
 
-type Resolver struct {
-	backend                Backend
-	urlHintContractAddress string
-	hashRegContractAddress string
+// registers a url to a content hash so that the content can be fetched
+// address is used as sender for the transaction and will be the owner of a new
+// registry entry on first time use
+// FIXME: silently doing nothing if sender is not the owner
+// note that with content addressed storage, this step is no longer necessary
+// it could be purely
+func (self *Resolver) RegisterUrl(address common.Address, hash common.Hash, url string) (txh string, err error) {
+	hashHex := common.Bytes2Hex(hash[:])
+	var urlHex string
+	urlb := []byte(url)
+	var cnt byte
+	n := len(urlb)
+
+	for n > 0 {
+		if n > 32 {
+			n = 32
+		}
+		urlHex = common.Bytes2Hex(urlb[:n])
+		urlb = urlb[n:]
+		n = len(urlb)
+		bcnt := make([]byte, 32)
+		bcnt[31] = cnt
+		data := registerUrlAbi +
+			hashHex +
+			common.Bytes2Hex(bcnt) +
+			common.Bytes2Hex(common.Hex2BytesFixed(urlHex, 32))
+		txh, err = self.backend.Transact(
+			address.Hex(),
+			UrlHintContractAddress,
+			"", txValue, txGas, txGasPrice,
+			data,
+		)
+		if err != nil {
+			return
+		}
+		cnt++
+	}
+	return
 }
 
-type Backend interface {
-	StorageAt(string, string) string
-}
+func (self *Resolver) Register(address common.Address, codehash, dochash common.Hash, url string) (txh string, err error) {
 
-func New(eth Backend, uhca, nrca string) *Resolver {
-	return &Resolver{eth, uhca, nrca}
+	_, err = self.RegisterContentHash(address, codehash, dochash)
+	if err != nil {
+		return
+	}
+	return self.RegisterUrl(address, dochash, url)
 }
 
+// resolution is costless non-transactional
+// implemented as direct retrieval from  db
 func (self *Resolver) KeyToContentHash(khash common.Hash) (chash common.Hash, err error) {
 	// look up in hashReg
+	at := common.Bytes2Hex(common.FromHex(HashRegContractAddress))
 	key := storageAddress(storageMapping(storageIdx2Addr(1), khash[:]))
-	hash := self.backend.StorageAt(self.hashRegContractAddress, key)
+	hash := self.backend.StorageAt(at, key)
 
 	if hash == "0x0" || len(hash) < 3 {
-		err = fmt.Errorf("GetHashReg: content hash not found")
+		err = fmt.Errorf("content hash not found for '%v'", khash.Hex())
 		return
 	}
-
 	copy(chash[:], common.Hex2BytesFixed(hash[2:], 32))
 	return
 }
 
+// retrieves the url-hint for the content hash -
+// if we use content addressed storage, this step is no longer necessary
 func (self *Resolver) ContentHashToUrl(chash common.Hash) (uri string, err error) {
 	// look up in URL reg
 	var str string = " "
@@ -69,7 +172,7 @@ func (self *Resolver) ContentHashToUrl(chash common.Hash) (uri string, err error
 	for len(str) > 0 {
 		mapaddr := storageMapping(storageIdx2Addr(1), chash[:])
 		key := storageAddress(storageFixedArray(mapaddr, storageIdx2Addr(idx)))
-		hex := self.backend.StorageAt(self.urlHintContractAddress, key)
+		hex := self.backend.StorageAt(UrlHintContractAddress, key)
 		str = string(common.Hex2Bytes(hex[2:]))
 		l := len(str)
 		for (l > 0) && (str[l-1] == 0) {
@@ -81,7 +184,7 @@ func (self *Resolver) ContentHashToUrl(chash common.Hash) (uri string, err error
 	}
 
 	if len(uri) == 0 {
-		err = fmt.Errorf("GetURLhint: URL hint not found")
+		err = fmt.Errorf("GetURLhint: URL hint not found for '%v'", chash.Hex())
 	}
 	return
 }
@@ -106,7 +209,8 @@ func storageMapping(addr, key []byte) []byte {
 	data := make([]byte, 64)
 	copy(data[0:32], key[0:32])
 	copy(data[32:64], addr[0:32])
-	return crypto.Sha3(data)
+	sha := crypto.Sha3(data)
+	return sha
 }
 
 func storageFixedArray(addr, idx []byte) []byte {
diff --git a/common/resolver/resolver_test.go b/common/resolver/resolver_test.go
index f5eb51437..02d12592e 100644
--- a/common/resolver/resolver_test.go
+++ b/common/resolver/resolver_test.go
@@ -20,6 +20,8 @@ var (
 )
 
 func NewTestBackend() *testBackend {
+	HashRegContractAddress = common.BigToAddress(common.Big0).Hex()[2:]
+	UrlHintContractAddress = common.BigToAddress(common.Big1).Hex()[2:]
 	self := &testBackend{}
 	self.contracts = make(map[string](map[string]string))
 
@@ -27,14 +29,13 @@ func NewTestBackend() *testBackend {
 	key := storageAddress(storageMapping(storageIdx2Addr(1), codehash[:]))
 	self.contracts[HashRegContractAddress][key] = hash.Hex()
 
-	self.contracts[URLHintContractAddress] = make(map[string]string)
+	self.contracts[UrlHintContractAddress] = make(map[string]string)
 	mapaddr := storageMapping(storageIdx2Addr(1), hash[:])
 
 	key = storageAddress(storageFixedArray(mapaddr, storageIdx2Addr(0)))
-	self.contracts[URLHintContractAddress][key] = common.ToHex([]byte(url))
+	self.contracts[UrlHintContractAddress][key] = common.ToHex([]byte(url))
 	key = storageAddress(storageFixedArray(mapaddr, storageIdx2Addr(1)))
-	self.contracts[URLHintContractAddress][key] = "0x00"
-
+	self.contracts[UrlHintContractAddress][key] = "0x00"
 	return self
 }
 
@@ -47,42 +48,46 @@ func (self *testBackend) StorageAt(ca, sa string) (res string) {
 	return
 }
 
+func (self *testBackend) Transact(fromStr, toStr, nonceStr, valueStr, gasStr, gasPriceStr, codeStr string) (string, error) {
+	return "", nil
+}
+
 func TestKeyToContentHash(t *testing.T) {
 	b := NewTestBackend()
-	res := New(b, URLHintContractAddress, HashRegContractAddress)
+	res := New(b)
 
 	got, err := res.KeyToContentHash(codehash)
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
 	} else {
 		if got != hash {
-			t.Errorf("incorrect result, expected %x, got %x: ", hash.Hex(), got.Hex())
+			t.Errorf("incorrect result, expected '%v', got '%v'", hash.Hex(), got.Hex())
 		}
 	}
 }
 
 func TestContentHashToUrl(t *testing.T) {
 	b := NewTestBackend()
-	res := New(b, URLHintContractAddress, HashRegContractAddress)
+	res := New(b)
 	got, err := res.ContentHashToUrl(hash)
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
 	} else {
-		if string(got) != url {
-			t.Errorf("incorrect result, expected %v, got %s: ", url, string(got))
+		if got != url {
+			t.Errorf("incorrect result, expected '%v', got '%s'", url, got)
 		}
 	}
 }
 
 func TestKeyToUrl(t *testing.T) {
 	b := NewTestBackend()
-	res := New(b, URLHintContractAddress, HashRegContractAddress)
+	res := New(b)
 	got, _, err := res.KeyToUrl(codehash)
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
 	} else {
-		if string(got) != url {
-			t.Errorf("incorrect result, expected %v, got %s: ", url, string(got))
+		if got != url {
+			t.Errorf("incorrect result, expected \n'%s', got \n'%s'", url, got)
 		}
 	}
 }