How to set msg.value in function call using ethers.js?

Question

I've got a function in my smart contract and i want it to take an argument that sets the msg.value and then pays it into the contract:

function deposit(uint256 amount) public payable {
    msg.value = amount
}

I'm trying to make a button on a website that sends a fixed amount into the contract like this:

async function sendTransaction() {
   if (typeof window.ethereum !== 'undefined') {
      await requestAccount()
      const provider = new ethers.providers.Web3Provider(window.ethereum);
      const signer = provider.getSigner();
      const contract = new ethers.Contract(contractAddress, contract.abi, signer);
      const transaction = await contract.deposit()
      await transaction.await()
   }

my question is, is there a way to set the msg.value from within the function its self, so i can call contract.deposit(value), or is there an easier way to set the value using ether.js?

Answer 1

You cannot change msg.value in the contract, it represents the amount of ether sent.

On frontend:

const transaction = await contract.deposit({ value: ethers.utils.parseEther("0.1") })
//sends 0.1 eth
await transaction.wait()

Change the 0.1 to the amount of ether you would like to send.

Answer 2

if I have price in wei (too big number for JavaScript, like price = 20000000000000000), I use:

const tx = await contract2.mint(tokenID, { value: ethers.BigNumber.from(price) });