extracting contract address from log.address instead of call.address

[DenisCarriere]

• make sure to use log.address for contract address in Transfer events
• make sure to use storage_change.address for contract address in Balance Change events

https://github.com/streamingfast/substreams-erc20-balance-changes/blob/99907f0bbb3bc0a4545bb1898b3883f6621381b9/src/maps.rs#L133C44-L133C56

ChatGPT context

In standard Ethereum logs, the log.address field always contains the address of the contract that emitted that log. So, if you are looking at an ERC‑20 Transfer event log, log.address will be the address of the token contract.

• log.address = the contract address that emitted the event.
• call.address (if exposed in certain tooling) may indicate the “to” or “from” in a lower-level call context, but is not the address that emitted the event.

Therefore, to find the token contract address from a Transfer event, you would look at log.address.

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Example (pseudocode)

for (let log of receipt.logs) {
  if (log.topics[0] === TRANSFER_TOPIC_SIGNATURE) {
    let tokenContractAddress = log.address;
    // decode the rest of the event data, e.g., from/to/value
  }
}

Here, tokenContractAddress is the ERC‑20 contract’s address.