ethers.js/lib.esm/abi/abi-coder.js
2023-06-01 17:52:58 -04:00

201 lines
7.6 KiB
JavaScript

/**
* When sending values to or receiving values from a [[Contract]], the
* data is generally encoded using the [ABI standard](link-solc-abi).
*
* The AbiCoder provides a utility to encode values to ABI data and
* decode values from ABI data.
*
* Most of the time, developers should favour the [[Contract]] class,
* which further abstracts a lot of the finer details of ABI data.
*
* @_section api/abi/abi-coder:ABI Encoding
*/
// See: https://github.com/ethereum/wiki/wiki/Ethereum-Contract-ABI
import { assertArgumentCount, assertArgument } from "../utils/index.js";
import { Reader, Writer } from "./coders/abstract-coder.js";
import { AddressCoder } from "./coders/address.js";
import { ArrayCoder } from "./coders/array.js";
import { BooleanCoder } from "./coders/boolean.js";
import { BytesCoder } from "./coders/bytes.js";
import { FixedBytesCoder } from "./coders/fixed-bytes.js";
import { NullCoder } from "./coders/null.js";
import { NumberCoder } from "./coders/number.js";
import { StringCoder } from "./coders/string.js";
import { TupleCoder } from "./coders/tuple.js";
import { ParamType } from "./fragments.js";
import { getAddress } from "../address/index.js";
import { getBytes, hexlify, makeError } from "../utils/index.js";
// https://docs.soliditylang.org/en/v0.8.17/control-structures.html
const PanicReasons = new Map();
PanicReasons.set(0x00, "GENERIC_PANIC");
PanicReasons.set(0x01, "ASSERT_FALSE");
PanicReasons.set(0x11, "OVERFLOW");
PanicReasons.set(0x12, "DIVIDE_BY_ZERO");
PanicReasons.set(0x21, "ENUM_RANGE_ERROR");
PanicReasons.set(0x22, "BAD_STORAGE_DATA");
PanicReasons.set(0x31, "STACK_UNDERFLOW");
PanicReasons.set(0x32, "ARRAY_RANGE_ERROR");
PanicReasons.set(0x41, "OUT_OF_MEMORY");
PanicReasons.set(0x51, "UNINITIALIZED_FUNCTION_CALL");
const paramTypeBytes = new RegExp(/^bytes([0-9]*)$/);
const paramTypeNumber = new RegExp(/^(u?int)([0-9]*)$/);
let defaultCoder = null;
function getBuiltinCallException(action, tx, data, abiCoder) {
let message = "missing revert data";
let reason = null;
const invocation = null;
let revert = null;
if (data) {
message = "execution reverted";
const bytes = getBytes(data);
data = hexlify(data);
if (bytes.length === 0) {
message += " (no data present; likely require(false) occurred";
reason = "require(false)";
}
else if (bytes.length % 32 !== 4) {
message += " (could not decode reason; invalid data length)";
}
else if (hexlify(bytes.slice(0, 4)) === "0x08c379a0") {
// Error(string)
try {
reason = abiCoder.decode(["string"], bytes.slice(4))[0];
revert = {
signature: "Error(string)",
name: "Error",
args: [reason]
};
message += `: ${JSON.stringify(reason)}`;
}
catch (error) {
message += " (could not decode reason; invalid string data)";
}
}
else if (hexlify(bytes.slice(0, 4)) === "0x4e487b71") {
// Panic(uint256)
try {
const code = Number(abiCoder.decode(["uint256"], bytes.slice(4))[0]);
revert = {
signature: "Panic(uint256)",
name: "Panic",
args: [code]
};
reason = `Panic due to ${PanicReasons.get(code) || "UNKNOWN"}(${code})`;
message += `: ${reason}`;
}
catch (error) {
message += " (could not decode panic code)";
}
}
else {
message += " (unknown custom error)";
}
}
const transaction = {
to: (tx.to ? getAddress(tx.to) : null),
data: (tx.data || "0x")
};
if (tx.from) {
transaction.from = getAddress(tx.from);
}
return makeError(message, "CALL_EXCEPTION", {
action, data, reason, transaction, invocation, revert
});
}
/**
* The **AbiCoder** is a low-level class responsible for encoding JavaScript
* values into binary data and decoding binary data into JavaScript values.
*/
export class AbiCoder {
#getCoder(param) {
if (param.isArray()) {
return new ArrayCoder(this.#getCoder(param.arrayChildren), param.arrayLength, param.name);
}
if (param.isTuple()) {
return new TupleCoder(param.components.map((c) => this.#getCoder(c)), param.name);
}
switch (param.baseType) {
case "address":
return new AddressCoder(param.name);
case "bool":
return new BooleanCoder(param.name);
case "string":
return new StringCoder(param.name);
case "bytes":
return new BytesCoder(param.name);
case "":
return new NullCoder(param.name);
}
// u?int[0-9]*
let match = param.type.match(paramTypeNumber);
if (match) {
let size = parseInt(match[2] || "256");
assertArgument(size !== 0 && size <= 256 && (size % 8) === 0, "invalid " + match[1] + " bit length", "param", param);
return new NumberCoder(size / 8, (match[1] === "int"), param.name);
}
// bytes[0-9]+
match = param.type.match(paramTypeBytes);
if (match) {
let size = parseInt(match[1]);
assertArgument(size !== 0 && size <= 32, "invalid bytes length", "param", param);
return new FixedBytesCoder(size, param.name);
}
assertArgument(false, "invalid type", "type", param.type);
}
/**
* Get the default values for the given %%types%%.
*
* For example, a ``uint`` is by default ``0`` and ``bool``
* is by default ``false``.
*/
getDefaultValue(types) {
const coders = types.map((type) => this.#getCoder(ParamType.from(type)));
const coder = new TupleCoder(coders, "_");
return coder.defaultValue();
}
/**
* Encode the %%values%% as the %%types%% into ABI data.
*
* @returns DataHexstring
*/
encode(types, values) {
assertArgumentCount(values.length, types.length, "types/values length mismatch");
const coders = types.map((type) => this.#getCoder(ParamType.from(type)));
const coder = (new TupleCoder(coders, "_"));
const writer = new Writer();
coder.encode(writer, values);
return writer.data;
}
/**
* Decode the ABI %%data%% as the %%types%% into values.
*
* If %%loose%% decoding is enabled, then strict padding is
* not enforced. Some older versions of Solidity incorrectly
* padded event data emitted from ``external`` functions.
*/
decode(types, data, loose) {
const coders = types.map((type) => this.#getCoder(ParamType.from(type)));
const coder = new TupleCoder(coders, "_");
return coder.decode(new Reader(data, loose));
}
/**
* Returns the shared singleton instance of a default [[AbiCoder]].
*
* On the first call, the instance is created internally.
*/
static defaultAbiCoder() {
if (defaultCoder == null) {
defaultCoder = new AbiCoder();
}
return defaultCoder;
}
/**
* Returns an ethers-compatible [[CallExceptionError]] Error for the given
* result %%data%% for the [[CallExceptionAction]] %%action%% against
* the Transaction %%tx%%.
*/
static getBuiltinCallException(action, tx, data) {
return getBuiltinCallException(action, tx, data, AbiCoder.defaultAbiCoder());
}
}
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