How to get ethereum gasPrice from a transaction hash?

Question

I need to get the gasUsed and gasPrice so that I can calculate the correct amount of gas required for a transaction.

I can get the gasUsed using:

var accountOneReceipt = await contractInstance.functionName(parameterOne, {from: accountOne});

var accountOneGasUsed = accountOneReceipt.receipt.gasUsed;

But there is no gasPrice parameter in transaction receipt.

Info: getTransactionReceipt

Answer 1

Instead of using getTransactionReceipt, I used getTransaction

So, to solve the above, we can use:

var accountOneGasPrice = (await web3.eth.getTransaction(accountOneReceipt.tx)).gasPrice

Where accountOneReceipt is the return value we receive from the above function call. And accountOneReceipt.tx to get the transaction hash.

Note: await is necessary for this code, as else you might get a pending state of the return value, which won't include the gasPrice.

Info: getTransaction