fix: keep track of bad proposers (#16006)

Fix #16001

Author: alexghr

yarn-project/validator-client/src/validator.test.ts

@@ -300,7 +300,7 @@ describe('ValidatorClient', () => {
       // We "remember" that we want to slash this person, up to the max penalty...
       await expect(
         validatorClient.shouldSlash({
-          validator: proposer,
+          validator: EthAddress.fromString(proposer.toString()), // create a copy of the EthAddress
           amount: config.slashInvalidBlockMaxPenalty,
           offense: Offense.INVALID_BLOCK,
         }),
@@ -309,7 +309,7 @@ describe('ValidatorClient', () => {
       // ...but no more than that
       await expect(
         validatorClient.shouldSlash({
-          validator: proposer,
+          validator: EthAddress.fromString(proposer.toString()),
           amount: config.slashInvalidBlockMaxPenalty + 1n,
           offense: Offense.INVALID_BLOCK,
         }),

yarn-project/validator-client/src/validator.ts

@@ -87,7 +87,7 @@ export class ValidatorClient extends (EventEmitter as new () => WatcherEmitter)
 
   private blockProposalValidator: BlockProposalValidator;
 
-  private proposersOfInvalidBlocks: Set<EthAddress> = new Set();
+  private proposersOfInvalidBlocks: Set<string> = new Set();
 
   protected constructor(
     private blockBuilder: IFullNodeBlockBuilder,
@@ -459,7 +459,7 @@ export class ValidatorClient extends (EventEmitter as new () => WatcherEmitter)
       this.proposersOfInvalidBlocks.delete(this.proposersOfInvalidBlocks.values().next().value!);
     }
 
-    this.proposersOfInvalidBlocks.add(proposer);
+    this.proposersOfInvalidBlocks.add(proposer.toString());
 
     this.emit(WANT_TO_SLASH_EVENT, [
       {
@@ -485,7 +485,8 @@ export class ValidatorClient extends (EventEmitter as new () => WatcherEmitter)
   public shouldSlash(args: WantToSlashArgs): Promise<boolean> {
     // note we don't check the offence here: we know this person is bad and we're willing to slash up to the max penalty.
     return Promise.resolve(
-      args.amount <= this.config.slashInvalidBlockMaxPenalty && this.proposersOfInvalidBlocks.has(args.validator),
+      args.amount <= this.config.slashInvalidBlockMaxPenalty &&
+        this.proposersOfInvalidBlocks.has(args.validator.toString()),
     );
   }