Moved fetcher to generic directory (methods have to remain public since it is in seperate package now), added FetchHash method, created ERC20 and generic getters which call the fetcher with specific contract methods (GetTotalSupply, GetBalance, GetAllowance for ERC20 getter, and GetOwner, GetStoppedStatus, GetStringName, GetHashName, GetStringSymbol, GetHashSymbol, and GetDecimals for generic getter). Getter tests cover all but GetBalance and GetAllowance, and also cover all of the Fetcher methods- but with only nil methodArgs. GetAllowance and GetBalance tests are not working against infura and these are the only contract method calls with arguments passed in so I suspect this might be where the issue lies. Have tested GetBalance using previous version of FetchContractData without the variadic input to the Pack method and it fails with the same error so I don’t think it is due to those changes.

examples/mocks/mocks.go

@@ -33,6 +33,12 @@ type Fetcher struct {
 	supply          big.Int
 	balance         map[string]*big.Int
 	allowance       map[string]map[string]*big.Int
+	owner           common.Address
+	stopped         bool
+	stringName      string
+	hashName        common.Hash
+	stringSymbol    string
+	hashSymbol      common.Hash
 }
 
 func (f *Fetcher) SetSupply(supply string) {
@@ -58,7 +64,7 @@ func (f *Fetcher) FetchBigInt(method, contractAbi, contractAddress string, block
 	}
 
 	if method == "balanceOf" {
-		rfl := reflect.ValueOf(methodArgs).Field(0)
+		rfl := reflect.ValueOf(methodArgs[0])
 		tokenHolderAddr := rfl.Interface().(string)
 		pnt := f.balance[tokenHolderAddr]
 		f.balance[tokenHolderAddr].Add(pnt, accumulator)
@@ -67,8 +73,8 @@ func (f *Fetcher) FetchBigInt(method, contractAbi, contractAddress string, block
 	}
 
 	if method == "allowance" {
-		rfl1 := reflect.ValueOf(methodArgs).Field(0)
-		rfl2 := reflect.ValueOf(methodArgs).Field(1)
+		rfl1 := reflect.ValueOf(methodArgs[0])
+		rfl2 := reflect.ValueOf(methodArgs[1])
 		tokenHolderAddr := rfl1.Interface().(string)
 		spenderAddr := rfl2.Interface().(string)
 		pnt := f.allowance[tokenHolderAddr][spenderAddr]
@@ -82,14 +88,132 @@ func (f *Fetcher) FetchBigInt(method, contractAbi, contractAddress string, block
 }
 
 func (f *Fetcher) FetchBool(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (bool, error) {
-	//TODO: this
-	return false, nil
+
+	f.Abi = contractAbi
+	f.ContractAddress = contractAddress
+	f.FetchedBlocks = append(f.FetchedBlocks, blockNumber)
+
+	b := true
+
+	if method == "stopped" {
+		f.stopped = b
+
+		return f.stopped, nil
+	}
+
+	return false, errors.New("invalid method argument")
 }
 
 func (f *Fetcher) FetchAddress(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (common.Address, error) {
-	//TODO: this
-	var adr common.Address
-	return adr, nil
+
+	f.Abi = contractAbi
+	f.ContractAddress = contractAddress
+	f.FetchedBlocks = append(f.FetchedBlocks, blockNumber)
+
+	adr := common.StringToAddress("test_address")
+
+	if method == "owner" {
+		f.owner = adr
+
+		return f.owner, nil
+	}
+	return common.StringToAddress(""), errors.New("invalid method argument")
+}
+
+func (f *Fetcher) FetchString(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (string, error) {
+
+	f.Abi = contractAbi
+	f.ContractAddress = contractAddress
+	f.FetchedBlocks = append(f.FetchedBlocks, blockNumber)
+
+	if method == "name" {
+		f.stringName = "test_name"
+
+		return f.stringName, nil
+	}
+
+	if method == "symbol" {
+		f.stringSymbol = "test_symbol"
+
+		return f.stringSymbol, nil
+	}
+	return "", errors.New("invalid method argument")
+}
+
+func (f *Fetcher) FetchHash(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (common.Hash, error) {
+
+	f.Abi = contractAbi
+	f.ContractAddress = contractAddress
+	f.FetchedBlocks = append(f.FetchedBlocks, blockNumber)
+
+	if method == "name" {
+		f.hashName = common.StringToHash("test_name")
+
+		return f.hashName, nil
+	}
+
+	if method == "symbol" {
+		f.hashSymbol = common.StringToHash("test_symbol")
+
+		return f.hashSymbol, nil
+	}
+	return common.StringToHash(""), errors.New("invalid method argument")
+}
+
+type Getter struct {
+	Fetcher Fetcher
+}
+
+func NewGetter(blockChain core.BlockChain) Getter {
+	return Getter{
+		Fetcher: Fetcher{
+			BlockChain: blockChain,
+		},
+	}
+}
+
+func (g *Getter) GetTotalSupply(contractAbi, contractAddress string, blockNumber int64) (big.Int, error) {
+	return g.Fetcher.FetchBigInt("totalSupply", contractAbi, contractAddress, blockNumber, nil)
+}
+
+func (g *Getter) GetBalance(contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (big.Int, error) {
+	return g.Fetcher.FetchBigInt("balanceOf", contractAbi, contractAddress, blockNumber, methodArgs)
+}
+
+func (g *Getter) GetAllowance(contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (big.Int, error) {
+	return g.Fetcher.FetchBigInt("allowance", contractAbi, contractAddress, blockNumber, methodArgs)
+}
+
+func (g *Getter) GetOwner(contractAbi, contractAddress string, blockNumber int64) (common.Address, error) {
+	return g.Fetcher.FetchAddress("owner", contractAbi, contractAddress, blockNumber, nil)
+}
+
+func (g *Getter) GetStoppedStatus(contractAbi, contractAddress string, blockNumber int64) (bool, error) {
+	return g.Fetcher.FetchBool("stopped", contractAbi, contractAddress, blockNumber, nil)
+}
+
+func (g *Getter) GetStringName(contractAbi, contractAddress string, blockNumber int64) (string, error) {
+	return g.Fetcher.FetchString("name", contractAbi, contractAddress, blockNumber, nil)
+}
+
+func (g *Getter) GetHashName(contractAbi, contractAddress string, blockNumber int64) (common.Hash, error) {
+	return g.Fetcher.FetchHash("name", contractAbi, contractAddress, blockNumber, nil)
+}
+
+func (g *Getter) GetStringSymbol(contractAbi, contractAddress string, blockNumber int64) (string, error) {
+	return g.Fetcher.FetchString("symbol", contractAbi, contractAddress, blockNumber, nil)
+}
+
+func (g *Getter) GetHashSymbol(contractAbi, contractAddress string, blockNumber int64) (common.Hash, error) {
+	return g.Fetcher.FetchHash("symbol", contractAbi, contractAddress, blockNumber, nil)
+}
+
+func (g *Getter) GetDecimals(contractAbi, contractAddress string, blockNumber int64) (big.Int, error) {
+	return g.Fetcher.FetchBigInt("decimals", contractAbi, contractAddress, blockNumber, nil)
+}
+
+func (g *Getter) GetBlockChain() core.BlockChain {
+	return g.Fetcher.BlockChain
 }
 
 type ERC20TokenRepository struct {