General: Warn when gas is high

[antazoey]

Overview

If the gas on a transaction is really high, warn the user.

Specification

Metamask uses >= 90% of blockGasLimit. https://github.com/MetaMask/metamask-extension/blob/develop/CHANGELOG.md?plain=1#L1893

Would that make sense for us too?

[fubuloubu]

Yeah, I think this is a good feature to add.

To clarify, this warns if the gas used by a transaction is getting close or exceeds a limit imposed by that particular network.

For EIP1559 chains, there are actually two limits: a target block limit (15m for Ethereum, can exceed this but probably not very easy in practice) and a max block limit (30m for Ethereum, cannot exceed this as it is a hard limit)

For non-EIP1559 chains, there is usually just one limit (and it depends on chain, I think BSC is something crazy like 120m)

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As an aside, at first I thought this meant to warn of congested network conditions, such as a spike in gas price, or for EIP1559 chains, seeing when the average block gas limit is above the target by a certain amount for the past X blocks. That might also be handy too, as a warning that things will be expensive. I've seen dapps warn about this in their UI

[antazoey]

So, to warn for congested networks, we need to track the block base gas fees ourselves? Will this require a little sqlite database?

[fubuloubu]

Well, actually EIP1559 has a "natural" definition for when congestion is happening: when more than 50% of the block gas limit is being used. So, we can just query a couple of blocks in the past and see if there's consistently like 70%+ being used or something.