Fix handling of nonce too low error

[kekonen]

Motivation

There is a problem currently in EscalatingPending Future implementation, which is responsible for backing the send_escalating method in Middleware.
The problem is in the part of the Future which tests for the nonce too low issues. That test consists of checking if the error's Display contains string nonce too low. The point here is that the error's display might not have nonce too low. For instance, a custom error's Display might not provide the desired nonce too low, while Debug would. Here is an example from POC which shows Display (error_display) and Debug(error_debug) of an error

 Poll::Ready(Err(e)) => {
     // kludge. Prevents erroring on "nonce too low" which indicates
     // a previous escalation confirmed during this broadcast attempt
     tracing::info!(
         error_display = %e,
         error_debug = ?e,
         "Want to see the diffrernce for error"
     );
     if format!("{}", e).contains("nonce too low") {

Debug line produces:

{"timestamp":"Jan 01 01:01:01.1337","level":"INFO","fields":{"message":"Want to see the diffrernce for error","error_display":"Max requests reached","error_debug":"JsonRpcClientError(MaxRequests([JsonRpcError(JsonRpcError { code: -32000, message: \"nonce too low\", data: None }), JsonRpcError(JsonRpcError { code: -32000, message: \"nonce too low\", data....

Solution

Obviously, Debug includes wrapped parts, which expose the desired line, whereas Display shows only Max requests reached. In order to fix the test I propose to change the format from format!("{}", e) to format!("{:?}", e), which would expose the debug.

[gakonst]

Good catch!

[kekonen]

@gakonst lints at WASM are failing, how shall we proceed?

[mattsse]

@gakonst lints at WASM are failing, how shall we proceed?

wasm has been fixed with #642, but there is a fmt issue here

Diff in /home/runner/work/ethers-rs/ethers-rs/ethers-providers/src/pending_escalator.rs at line 187:
                         let fut = this.provider.send_raw_transaction(next_to_broadcast);
                         *this.state = BroadcastingNew(fut);
                         cx.waker().wake_by_ref();
-                        return Poll::Pending;
+                        return Poll::Pending
                     }
                 }
                 check_all_receipts!(cx, this);

please use nightly formatting