Make sure the adder collator fails when something is wrong (#2450)

As futures most of the time are catching panics and we don't check this,
it could happen that we have some statement that isn't correct but the
test succeeds successfully.

polkadot/Cargo.lock

@@ -9217,7 +9217,6 @@ dependencies = [
 name = "test-parachain-adder-collator"
 version = "0.7.26"
 dependencies = [
- "assert_matches",
  "futures 0.3.12",
  "futures-timer 3.0.2",
  "log",

polkadot/parachain/test-parachains/adder/collator/Cargo.toml

@@ -15,7 +15,6 @@ futures = "0.3.12"
 futures-timer = "3.0.2"
 log = "0.4.13"
 structopt = "0.3.21"
-assert_matches = "1.4.0"
 
 test-parachain-adder = { path = ".." }
 polkadot-primitives = { path = "../../../../primitives" }

polkadot/parachain/test-parachains/adder/collator/src/lib.rs

@@ -28,7 +28,6 @@ use std::{
 };
 use test_parachain_adder::{execute, hash_state, BlockData, HeadData};
 use futures::channel::oneshot;
-use assert_matches::assert_matches;
 
 /// The amount we add when producing a new block.
 ///
@@ -180,11 +179,13 @@ impl Collator {
 			let seconded_collations = seconded_collations.clone();
 			spawner.spawn("adder-collator-seconded", async move {
 				if let Ok(res) = recv.await {
-					assert_matches!(
+					if !matches!(
 						res.payload(),
 						Statement::Seconded(s) if s.descriptor.pov_hash == pov.hash(),
-						"Seconded statement should match our collation!",
-					);
+					) {
+						log::error!("Seconded statement should match our collation: {:?}", res.payload());
+						std::process::exit(-1);
+					}
 
 					seconded_collations.fetch_add(1, Ordering::Relaxed);
 				}