import { AbiDefinition, AbiType, ContractAbi, DataItem, MethodAbi } from 'ethereum-types';
import * as _ from 'lodash';
import { BigNumber } from './configured_bignumber';
export type EthersParamName = null | string | EthersNestedParamName;
export interface EthersNestedParamName {
name: string | null;
names: EthersParamName[];
}
// Note(albrow): This function is unexported in ethers.js. Copying it here for
// now.
// Source: https://github.com/ethers-io/ethers.js/blob/884593ab76004a808bf8097e9753fb5f8dcc3067/contracts/interface.js#L30
function parseEthersParams(params: DataItem[]): { names: EthersParamName[]; types: string[] } {
const names: EthersParamName[] = [];
const types: string[] = [];
params.forEach((param: DataItem) => {
if (param.components != null) {
let suffix = '';
const arrayBracket = param.type.indexOf('[');
if (arrayBracket >= 0) {
suffix = param.type.substring(arrayBracket);
}
const result = parseEthersParams(param.components);
names.push({ name: param.name || null, names: result.names });
types.push('tuple(' + result.types.join(',') + ')' + suffix);
} else {
names.push(param.name || null);
types.push(param.type);
}
});
return {
names,
types,
};
}
// returns true if x is equal to y and false otherwise. Performs some minimal
// type conversion and data massaging for x and y, depending on type. name and
// type should typically be derived from parseEthersParams.
function isAbiDataEqual(name: EthersParamName, type: string, x: any, y: any): boolean {
if (_.isUndefined(x) && _.isUndefined(y)) {
return true;
} else if (_.isUndefined(x) && !_.isUndefined(y)) {
return false;
} else if (!_.isUndefined(x) && _.isUndefined(y)) {
return false;
}
if (_.endsWith(type, '[]')) {
// For array types, we iterate through the elements and check each one
// individually. Strangely, name does not need to be changed in this
// case.
if (x.length !== y.length) {
return false;
}
const newType = _.trimEnd(type, '[]');
for (let i = 0; i < x.length; i++) {
if (!isAbiDataEqual(name, newType, x[i], y[i])) {
return false;
}
}
return true;
}
if (_.startsWith(type, 'tuple(')) {
if (_.isString(name)) {
throw new Error('Internal error: type was tuple but names was a string');
} else if (_.isNull(name)) {
throw new Error('Internal error: type was tuple but names was a null');
}
// For tuples, we iterate through the underlying values and check each
// one individually.
const types = splitTupleTypes(type);
if (types.length !== name.names.length) {
throw new Error(
`Internal error: parameter types/names length mismatch (${types.length} != ${name.names.length})`,
);
}
for (let i = 0; i < types.length; i++) {
// For tuples, name is an object with a names property that is an
// array. As an example, for orders, name looks like:
//
// {
// name: 'orders',
// names: [
// 'makerAddress',
// // ...
// 'takerAssetData'
// ]
// }
//
const nestedName = _.isString(name.names[i])
? (name.names[i] as string)
: ((name.names[i] as EthersNestedParamName).name as string);
if (!isAbiDataEqual(name.names[i], types[i], x[nestedName], y[nestedName])) {
return false;
}
}
return true;
} else if (type === 'address' || type === 'bytes') {
// HACK(albrow): ethers.js sometimes changes the case of addresses/bytes
// when decoding/encoding. To account for that, we convert to lowercase
// before comparing.
return _.isEqual(_.toLower(x), _.toLower(y));
} else if (_.startsWith(type, 'uint') || _.startsWith(type, 'int')) {
return new BigNumber(x).eq(new BigNumber(y));
}
return _.isEqual(x, y);
}
// splitTupleTypes splits a tuple type string (of the form `tuple(X)` where X is
// any other type or list of types) into its component types. It works with
// nested tuples, so, e.g., `tuple(tuple(uint256,address),bytes32)` will yield:
// `['tuple(uint256,address)', 'bytes32']`. It expects exactly one tuple type as
// an argument (not an array).
function splitTupleTypes(type: string): string[] {
if (_.endsWith(type, '[]')) {
throw new Error('Internal error: array types are not supported');
} else if (!_.startsWith(type, 'tuple(')) {
throw new Error('Internal error: expected tuple type but got non-tuple type: ' + type);
}
// Trim the outtermost tuple().
const trimmedType = type.substring('tuple('.length, type.length - 1);
const types: string[] = [];
let currToken = '';
let parenCount = 0;
// Tokenize the type string while keeping track of parentheses.
for (const char of trimmedType) {
switch (char) {
case '(':
parenCount += 1;
currToken += char;
break;
case ')':
parenCount -= 1;
currToken += char;
break;
case ',':
if (parenCount === 0) {
types.push(currToken);
currToken = '';
break;
} else {
currToken += char;
break;
}
default:
currToken += char;
break;
}
}
types.push(currToken);
return types;
}
export const abiUtils = {
parseEthersParams,
isAbiDataEqual,
splitTupleTypes,
parseFunctionParam(param: DataItem): string {
if (param.type === 'tuple') {
// Parse out tuple types into {type_1, type_2, ..., type_N}
const tupleComponents = param.components;
const paramString = _.map(tupleComponents, component => abiUtils.parseFunctionParam(component));
const tupleParamString = `{${paramString}}`;
return tupleParamString;
}
return param.type;
},
getFunctionSignature(methodAbi: MethodAbi): string {
const functionName = methodAbi.name;
const parameterTypeList = _.map(methodAbi.inputs, (param: DataItem) => abiUtils.parseFunctionParam(param));
const functionSignature = `${functionName}(${parameterTypeList})`;
return functionSignature;
},
/**
* Solidity supports function overloading whereas TypeScript does not.
* See: https://solidity.readthedocs.io/en/v0.4.21/contracts.html?highlight=overload#function-overloading
* In order to support overloaded functions, we suffix overloaded function names with an index.
* This index should be deterministic, regardless of function ordering within the smart contract. To do so,
* we assign indexes based on the alphabetical order of function signatures.
*
* E.g
* ['f(uint)', 'f(uint,byte32)']
* Should always be renamed to:
* ['f1(uint)', 'f2(uint,byte32)']
* Regardless of the order in which these these overloaded functions are declared within the contract ABI.
*/
renameOverloadedMethods(inputContractAbi: ContractAbi): ContractAbi {
const contractAbi = _.cloneDeep(inputContractAbi);
const methodAbis = contractAbi.filter((abi: AbiDefinition) => abi.type === AbiType.Function) as MethodAbi[];
// Sort method Abis into alphabetical order, by function signature
const methodAbisOrdered = _.sortBy(methodAbis, [
(methodAbi: MethodAbi) => {
const functionSignature = abiUtils.getFunctionSignature(methodAbi);
return functionSignature;
},
]);
// Group method Abis by name (overloaded methods will be grouped together, in alphabetical order)
const methodAbisByName: { [key: string]: MethodAbi[] } = {};
_.each(methodAbisOrdered, methodAbi => {
(methodAbisByName[methodAbi.name] || (methodAbisByName[methodAbi.name] = [])).push(methodAbi);
});
// Rename overloaded methods to overloadedMethodName1, overloadedMethodName2, ...
_.each(methodAbisByName, methodAbisWithSameName => {
_.each(methodAbisWithSameName, (methodAbi, i: number) => {
if (methodAbisWithSameName.length > 1) {
const overloadedMethodId = i + 1;
const sanitizedMethodName = `${methodAbi.name}${overloadedMethodId}`;
const indexOfExistingAbiWithSanitizedMethodNameIfExists = _.findIndex(
methodAbis,
currentMethodAbi => currentMethodAbi.name === sanitizedMethodName,
);
if (indexOfExistingAbiWithSanitizedMethodNameIfExists >= 0) {
const methodName = methodAbi.name;
throw new Error(
`Failed to rename overloaded method '${methodName}' to '${sanitizedMethodName}'. A method with this name already exists.`,
);
}
methodAbi.name = sanitizedMethodName;
}
});
});
return contractAbi;
},
};
