RPC to dry run a transaction

[xlc]

A new RPC to allow user submit transaction and dry run it and return all events.

It should respect to weight limits so this cannot be used to DOS the node.

Should have an option to disable signature validation to make this more useful (able to detect transaction will not success before asking user to sign).

state_call with BlockBuilder_apply_extrinsic may be able to achieve something similar but it is way too hard to use and does not expose events.

This will need to be an unsafe RPC to avoid ddos nodes.

[bkchr]

And this is an unsafe RPC?

[xlc]

In terms of safeness, I think this is similar to submit extrinsic? or state_call?

Any places for me to check is state_call unsafe other than reading the code?

[bkchr]

I mean, if you open a RPC where everyone can send you transactions to dry run them. They can ddos your node. Especially if they can disable signature checking.