Questions tagged [solidity]
Solidity is a contract-oriented, high-level language whose syntax is similar to that of JavaScript and it is designed for writing smart contracts in Ethereum to run on the EVM. Solidity is statically typed, supports inheritance, libraries and complex user-defined types among other features.
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How Can I Identify the Blockchain Where a Smart Contract Is Deployed Using Its Address?
I am trying to identify the specific blockchain where a smart contract has been deployed using its deployment address. However, I am unable to find a clear source or method for doing so.
When I looked ...
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How is exchange rate calculated on DEX platforms like uniswap and sushiswap?
I started getting into the crypto scene and I read about liquidity pools but I am not sure how to get exchange rates into my javascript code, I looked for API's and SDK's but couldn't find any for the ...
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Percentage Calculation in Solidity
I am wondering if my idea is correct.
Total shares: 11,000
User A's shares : 10,000
User A's share percentage = User A's share / Total share.
= 10,000 / 11,000
...
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Exchange tokens with different decimal
I'm in the process of developing a smart contract that allows users to purchase tokens. However, I'm encountering an issue with the price calculation:
The token I'm selling (let's call it "...
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removeLiqudityWithPermit: Invalid Signature
So, I am trying to remove liquidity from a pancake v2 pair and I do not understand why this is not working. I am looking at the code, and I've triple checked every value, I don' think I am doing ...
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How do I update a campaign without it creating a new campaign?
I'm working on the update campaign feature in a project.
First Issue - Prefilling the form fields
I want first to prefill the form fields then from there, a user can change what they want.
In the /...
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Using getter function in require statement is resulting in an error
I am using Remix ide to deploy the contract, Order of deployment is Test1 ===> Test2(address of Test1), Amount send for the function in Test2 contract is 1 Ether
I am getting an error while ...
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Restricting External Adapter Access to a Specific Smart Contract: Is it Feasible?
How can I ensure that my external adapter is only accessible by a specific contract? Does the Post express middleware in the external adapter have a header key indicating the calling smart contract? I'...
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Is it possible transaction A get executed while transaction B is in middle of execution in the same block?
Imagine I have deposit function which can receive funds from user and the amount sent will be updated in state based on balanceBefore and balanceAfter of token in the contract:
1: function deposit(...
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How to get address of deployed smart contract in hardhat
I have two files, Token.sol and Token.js for Testing:-
Token.sol
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.19;
import "hardhat/console.sol";
contract Token{
string ...
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Debugging tools available to better target the errors reported by the safe app and safe provider?
When trying to make my dapp compatible with a safe app, the safe app raised errors when necessary, but for some it's difficult to locate the error in the code (because there's no reference to code ...
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Code 608 when using a dapp with a safe infrastructure locally (Fuji Testnet)
Context
I have a perfectly working dapp I'm trying to adapt to a Safe App. To test the dapp, I have to use a test network (Avalanche Fuji Testnet here), which is not supported by the current Safe web ...
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transactionContract.addtoblockchain is not a function
Calling a specific function from smart contract through react jsx file , console is giving me error "transactionContract.addtoblockchain is not a function", even the function is present in ...
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Does Foundry Support Dynamical Library Linking in Solidity?
I would like to deploy a contract that has external library dependencies that need to be dynamically linked. This is typically done in hardhat ethers as follows:
const MyLibrary = await ethers....
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how to deploy factory smart contract
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;
contract Car {
string public model;
address public carAddr;
constructor( string memory _model) {
model = _model;
...
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Error: VM Exception while processing transaction: reverted with reason string 'Can't buy Coffee for free'
deploy.js ->
const hre = require("hardhat");
const { ethers } = require('hardhat');
const { utils } = require('hardhat');
// Returns the ether balance of a given address.
async function ...
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Wrong argument count for function call: 2 arguments given but expected 1
uint256 adminTokenBalance = balanceOf(owner(), tokenId);
require(adminTokenBalance > 0, "Admin does not hold expired token");
_transfer(owner(), msg.sender, tokenId, ...
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Flash loan on Pancakeswap utilizing equalizer.finance provider
I'm trying to write a smart contract on Remix-Ethereum IDE to do a Flash loan on Pancakeswap utilizing equalizer.finance provider.
the smart contract function is to
borrow token1
swap token1 with ...
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Decentralized E-Authentication System for Student Portal with Ethereum-based Decentralized Identity Management and Access Control
I was given a final year project to build a Decentralized E-Authentication System for Student Portal with Ethereum-based Decentralized Identity Management and Access Control. I'm new to web3, please ...
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Foundry tests fails with EvmError: Revert Counterexample, when calling transfer
I'm getting an error when trying to test my treasury:
[FAIL. Reason: EvmError: Revert Counterexample: calldata=...
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--solc --userdoc --devdoc File not found. Searched the following locations: ""
When trying to generate user documentation and developer documentation from the NatSpec of a smart contract with solc --userdoc --devdoc MarketPlaceCustodial.sol by following the official ...
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I am trying to replicate a deployed contract but it doesn't work for me. I want to learn to please tell me what I am doing wrong. Goerli lets me do it
contract : https://codeshare.io/BA1yqK
The error : Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending?
Returned ...
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Looking for a free Solidity reversing tool (not decompiler)
I found there is a Solidity reversing plugin for IDA Pro and Binary Ninja, but it costs a lot for students. Are there any free Solidity plugins? Or are there any other free reversing tools that have a ...
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Creating an ICO contract
I'm creating a simple ICO contract, it sends the amount of the token bought to the buyer as soon as the contract receives ether, and then sends the received ether to a different wallet, I've been ...
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How to test Chainlink Operator.sol in Foundry and find cause of revert?
I am trying to rewrite this test from Truffle/Javascript to Foundry/Solidity.
This is the specific part I am stuck on:
it("should not fulfill from unauthorized job", async function () {
...
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Can a smart contract approval token of wallet address to a spender?
For example, if wallet A calls a method of contract B, and this method authorizes Token X from wallet A to contract C, can the contract B do this?
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What are the best up-to-date secure approaches of generating pseudorandom number in Solidity? [duplicate]
I am thinking about creating a lottery with more than one winner and one round for users. Please don't consider usual 'commit-reveal' scheme. However, person can claim rewards on their own at the end ...
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addLiquidityETH : TransferHelper: TRANSFER_FROM_FAILED
I am trying to understand this code. I have tried different variations, but whatever I do, it is not working. I get this Error: VM Exception while processing transaction: reverted with reason string '...
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what is the difference between address and target in ethers
const hre = require("hardhat");
const { ethers } = require('hardhat');
// Returns the ether balance of a given address.
async function getBalance(address) {
const balanceBigInt = await ...
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error Dai/insufficient-allowance even when sufficient amount has been approved
I am testing smart contract interaction with Gains.trade on hardhat mainnet fork. However i always got this error Error: VM Exception while processing transaction: reverted with reason string 'Dai/...
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how can i deploy my Dapp?
what if I have deployed my smart contract on truffle and used ganache to deploy the same and i havn't used any test network, so if I go to deploy it on netlify to demonstrate the same will it work??
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Cannot read properties of undefined (reading 'formatEther')
const hre = require("hardhat");
// Returns the ether balance of a given address.
async function getBalance(address) {
const balanceBigInt = await hre.ethers.provider.getBalance(address);
...
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Implementing Verkle Trees in Solidity, Generating Proofs, and Using Zokrates
I'm working on implementing Verkle Trees and looking for guidance on how to implement Verkle Trees in Solidity. I have a working python code with implementation of verkle trees, proof generation and ...
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Smart contract in Solidity: call a function from a contract written in Vyper
I'm writing a contract in Solidity, in which I'm trying to call a function from another contract written in Vyper.
To do so, I've checked the corresponding function in the ABI of the Vyper contract, ...
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Solidity GAS Fee different for pure and non-pure functions
I am using REMIX IDE, and running the following codes to learn about the gas limit.
GAS LIMIT IS 3000000
First I ran this code,
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.3;
contract gas{
...
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Hardhat compile code on file change (like remix)
Is there any way (preferably an official Hardhat plugin) to automatically compile the Smart Contracts' code on file change?
I'd want to have the same developer experience as when using Remix, or ...
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What does it mean when we say some proposal is compliant with ERC4337?
https://twitter.com/johnrising_/status/1688949899419693068?s=46&t=LOD6kc1r6c1fbygDtT3Qvg
I was reading this twitter thread today . Then I read about EIP6900
https://eips.ethereum.org/EIPS/eip-6900
...
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How to calculate the Max Buy and max sell of an erc20 token even without liquidity
How to calculate the Max Buy and max sell of an erc20 token even without liquidity.
There are many Ethereum tokens with a limit to the maximum amount of tokens that can be bought at once and sold.
I ...
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2
answers
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Mint From Existing Contract
I have the following contract that is already deployed (pasted below). I can see where the constructor() method is doing an emit Transfer from the 0x0 (zero) address to the deployer address in order ...
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Call revert exception error
I am getting this error when I try to access a string from a dynamic array
call revert exception; VM Exception while processing transaction: reverted with panic code 50 [ See: https://links.ethers.org/...
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How can I retrieve the address of an external library in Solidity?
I'm currently working on a Solidity project that involves using external libraries. I need to access the address of an external library within my contract.
Is there a way to retrieve an external ...
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Type contract is not implicitly convertible to expected type tuple in my foundry setup
I am trying to test my project, but keeps throwing an error in the test setup.
//SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;
import {Test} from "forge-std/Test.sol";
import {...
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version problem in hardhat
const hre = require("hardhat");
// Returns the ether balance of a given address.
async function getBalance(address) {
const balanceBigInt = await hre.ethers.provider.getBalance(address);
...
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How can one OZ Transparent Proxy access data from another OZ Transparent proxy?
Scenario:
I have two proxies:
Root Proxy, this is created during deployment
Secondary proxies, this is created at start of each transaction, and is initialized with the context of the transaction
...
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Hardhat and foundry, contract bytecode different
I'm developing a contract in hardhat project. But now I want to write test by foundry. My problem is I'm using create2, but when running contract by hardhat and foundry they gave different addresses. ...
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AAVE：COOLDOWN_SECONDS and UNSTAKE_WINDOW
AAVE V1 's redeem() function requires us to wait for COOLDOWN_SECONDS and withdraw money in UNSTAKE_WINDOW.
/**
* @dev Redeems staked tokens, and stop earning rewards
* @param to Address to ...
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How to handle calls to mapping of big structs
Good day y'all, i'm tying to write a contract which is supposed to interact with another one that has a big struct that i need to retrieve to do some calculation, the struct have 14 properties and it ...
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What is the purpose of the constructor?
contract Constructor {
string public name;
// I thought constructor will prevent the name to change but after deployed the contract, calling the function resulted in changing the name?????
...
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TypeError: AbiCoder is not a constructor
I am working with patrick solidity course on youtube and have gotten to the point of carrying out unit testing. I am having this issue
getting this error
const { assert, expect } = require("...
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Is it possible to use Foundry to monitor the mempool?
I have been able to use other frameworks / libraries (e.g., web3.py and ethers.py) to monitor mempool events.
I see that anvil has one mention in the docs related to mempool monitoring (a switch for ...
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