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ethcoder: add new AbiUnmarshalStringValuesAny to unmarshal string val…
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…ues to runtime objects, with array and tuple support
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@pkieltyka
pkieltyka committed Oct 13, 2024
1 parent 6cd5ab0 commit 8ba94e8
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Showing 4 changed files with 413 additions and 11 deletions.
262 changes: 258 additions & 4 deletions ethcoder/abi.go
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Original file line number Diff line number Diff line change
Expand Up @@ -65,6 +65,7 @@ func AbiEncodeMethodCalldata(methodExpr string, argValues []interface{}) ([]byte
if err != nil {
return nil, err
}

data, err := mabi.Pack(methodName, argValues...)
if err != nil {
return nil, err
Expand Down Expand Up @@ -116,9 +117,252 @@ func AbiMarshalStringValues(argTypes []string, input []byte) ([]string, error) {
return StringifyValues(values)
}

// AbiDecodeStringValues will take an array of ethereum types and string values, and decode
// the string values to runtime objects.
func AbiUnmarshalStringValues(argTypes []string, stringValues []string) ([]interface{}, error) {
// AbiUnmarshalStringValuesAny will take an array of ethereum types as string values, and decode
// the string values to runtime objects. This allows simple string value input from an app
// or user, and converts them to the appropriate runtime objects.
//
// NOTE: this is a variant of AbiUnmarshalStringValues but the `stringValues` argument type
// is []any, in order to support input types of array of strings for abi types like `address[]`
// and tuples.
//
// For example, some valid inputs:
// - AbiUnmarshalStringValuesAny([]string{"address","uint256"}, []any{"0x1234...", "543"})
// returns []interface{}{common.HexToAddress("0x1234..."), big.NewInt(543)}
// - AbiUnmarshalStringValuesAny([]string{"address[]", []any{[]string{"0x1234...", "0x5678..."}})
// returns []interface{}{[]common.Address{common.HexToAddress("0x1234..."), common.HexToAddress("0x5678...")}}
// - AbiUnmarshalStringValuesAny([]string{"(address,uint256)"}, []any{[]any{"0x1234...", "543"}})
// returns []interface{}{[]interface{}{common.HexToAddress("0x1234..."), big.NewInt(543)}}
//
// The common use for this method is to pass a JSON object of string values for an abi method
// and have it properly encode to the native abi types.
func AbiUnmarshalStringValuesAny(argTypes []string, stringValues []any) ([]any, error) {
if len(argTypes) != len(stringValues) {
return nil, fmt.Errorf("ethcoder: argTypes and stringValues must be of equal length")
}

values := []interface{}{}

for i, typ := range argTypes {
v := stringValues[i]

switch typ {
case "address":
s, ok := v.(string)
if !ok {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting address in hex", i)
}

// expected "0xabcde......"
if !strings.HasPrefix(s, "0x") {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting address in hex", i)
}
values = append(values, common.HexToAddress(s))
continue

case "string":
s, ok := v.(string)
if !ok {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting string", i)
}

// expected: string value
values = append(values, s)
continue

case "bytes":
s, ok := v.(string)
if !ok {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting bytes in hex", i)
}

// expected: bytes in hex encoding with 0x prefix
if strings.HasPrefix(s, "0x") {
values = append(values, common.Hex2Bytes(s[2:]))
continue
} else {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting bytes in hex", i)
}

case "bool":
s, ok := v.(string)
if !ok {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting bool as 'true' or 'false'", i)
}

// expected: "true" | "false"
if s == "true" {
values = append(values, true)
} else if s == "false" {
values = append(values, false)
} else {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting bool as 'true' or 'false'", i)
}
continue
}

// numbers
if match := regexArgNumber.FindStringSubmatch(typ); len(match) > 0 {
s, ok := v.(string)
if !ok {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting number as string", i)
}

size, err := strconv.ParseInt(match[2], 10, 64)
if err != nil {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid. expecting %s. reason: %w", i, typ, err)
}
if (size%8 != 0) || size == 0 || size > 256 {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid. invalid number type '%s'", i, typ)
}

num := big.NewInt(0)
num, ok = num.SetString(s, 10)
if !ok {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid. expecting number. unable to set value of '%s'", i, s)
}
values = append(values, num)
continue
}

// bytesXX (fixed)
if match := regexArgBytes.FindStringSubmatch(typ); len(match) > 0 {
s, ok := v.(string)
if !ok {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting bytes in hex", i)
}

if !strings.HasPrefix(s, "0x") {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting bytes in hex", i)
}
size, err := strconv.ParseInt(match[1], 10, 64)
if err != nil {
return nil, err
}
if size == 0 || size > 32 {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, bytes type '%s' is invalid", i, typ)
}
val := common.Hex2Bytes(s[2:])
if int64(len(val)) != size {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, %s type expects a %d byte value but received %d", i, typ, size, len(val))
}
values = append(values, val)
continue
}

// arrays
// TODO: can we avoid regexp...?
if match := regexArgArray.FindStringSubmatch(typ); len(match) > 0 {
baseTyp := match[1]
if match[2] == "" {
match[2] = "0"
}
count, err := strconv.ParseInt(match[2], 10, 64)
if err != nil {
return nil, err
}

if baseTyp != "address" {
submatch := regexArgNumber.FindStringSubmatch(baseTyp)
if len(submatch) == 0 {
return nil, fmt.Errorf("ethcoder: value at position %d of type %s is unsupported. Only number string arrays are presently supported", i, typ)
}
}

s, ok := v.([]string)
if !ok {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting string array", i)
}

stringValues := s
if count > 0 && len(stringValues) != int(count) {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, array size does not match required size of %d", i, count)
}

var arrayArgs []string
for i := 0; i < len(stringValues); i++ {
arrayArgs = append(arrayArgs, baseTyp)
}

arrayValues, err := AbiUnmarshalStringValues(arrayArgs, stringValues)
if err != nil {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, failed to get string values for array - %w", i, err)
}

if baseTyp == "address" {
var addresses []common.Address
for _, element := range arrayValues {
address, ok := element.(common.Address)
if !ok {
return nil, fmt.Errorf("ethcoder: expected common.Address, got %v", element)
}
addresses = append(addresses, address)
}
values = append(values, addresses)
} else {
var bnArray []*big.Int
for _, n := range arrayValues {
bn, ok := n.(*big.Int)
if !ok {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting array element to be *big.Int", i)
}
bnArray = append(bnArray, bn)
}
values = append(values, bnArray)
}
}

// tuples
idx := strings.Index(typ, "(")
idx2 := strings.Index(typ, ")")
if idx >= 0 && idx2 > 0 {

// TODO: add nested tuple support in the future:
// need to encode inner parts first, ind the next '(' after idx .. etc.. and call AbiUnmarshalStringValuesAny recursively

t := typ[idx+1 : idx2]
idx := strings.Index(t, "(")
if idx >= 0 {
return nil, fmt.Errorf("ethcoder: value at position %d has found a nested tuple, which is unsupported currently, please contact support and make a request", i)
}
args := strings.Split(t, ",")

var vv []any
switch v := v.(type) {
case []any:
if len(v) != len(args) {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, tuple size does not match required size of %d", i, len(args))
}
vv = v
case []string:
if len(v) != len(args) {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, tuple size does not match required size of %d", i, len(args))
}
vv = make([]any, len(v))
for i, x := range v {
vv[i] = x
}
default:
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, expecting array of any or string", i)
}

out, err := AbiUnmarshalStringValuesAny(args, vv)
if err != nil {
return nil, fmt.Errorf("ethcoder: value at position %d is invalid, failed to get string values for tuple: %w", i, err)
}
values = append(values, out)
}
}

return values, nil
}

// AbiUnmarshalStringValues will take an array of ethereum types as string values, and decode
// the string values to runtime objects. This allows simple string value input from an app
// or user, and converts them to the appropriate runtime objects.
//
// The common use for this method is to pass a JSON object of string values for an abi method
// and have it properly encode to the native abi types.
func AbiUnmarshalStringValues(argTypes []string, stringValues []string) ([]any, error) {
if len(argTypes) != len(stringValues) {
return nil, fmt.Errorf("ethcoder: argTypes and stringValues must be of equal length")
}
Expand Down Expand Up @@ -203,6 +447,7 @@ func AbiUnmarshalStringValues(argTypes []string, stringValues []string) ([]inter
}

// arrays
// TODO: can we avoid regexp...?
if match := regexArgArray.FindStringSubmatch(typ); len(match) > 0 {
baseTyp := match[1]
if match[2] == "" {
Expand All @@ -216,7 +461,7 @@ func AbiUnmarshalStringValues(argTypes []string, stringValues []string) ([]inter
if baseTyp != "address" {
submatch := regexArgNumber.FindStringSubmatch(baseTyp)
if len(submatch) == 0 {
return nil, fmt.Errorf("ethcoder: value at position %d of type %s is unsupported. Only number string arrays are presently supported.", i, typ)
return nil, fmt.Errorf("ethcoder: value at position %d of type %s is unsupported. Only number string arrays are presently supported", i, typ)
}
}

Expand Down Expand Up @@ -261,6 +506,15 @@ func AbiUnmarshalStringValues(argTypes []string, stringValues []string) ([]inter
values = append(values, bnArray)
}
}

// tuples
idx := strings.Index(typ, "(")
idx2 := strings.Index(typ, ")")
if idx >= 0 && idx2 > 0 {
// NOTE: perhaps we can support tuples here too..? but really its better to use
// AbiUnmarshalStringValuesAny anyways.
return nil, fmt.Errorf("ethcoder: tuples are not supported by this method, use AbiUnmarshalStringValuesAny instead")
}
}

return values, nil
Expand Down
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