e2etest: refactor generateProofs, use buffered chan

cmd/end2endtest/helpers.go

@@ -243,21 +243,11 @@ func (t *e2eElection) generateProofs(root types.HexBytes, isAnonymousVoting bool
 		proof   *apiclient.CensusProof
 		address string
 	}
-	proofs := make(map[string]*apiclient.CensusProof, len(t.voterAccounts))
-	proofCh := make(chan *voterProof)
-	stopProofs := make(chan bool)
-	go func() {
-		for {
-			select {
-			case p := <-proofCh:
-				proofs[p.address] = p.proof
-			case <-stopProofs:
-				return
-			}
-		}
-	}()
+	proofCh := make(chan *voterProof, len(t.voterAccounts))
 
-	addNaccounts := func(accounts []*ethereum.SignKeys, wg *sync.WaitGroup) {
+	var wg sync.WaitGroup
+
+	addNaccounts := func(accounts []*ethereum.SignKeys) {
 		defer wg.Done()
 		log.Infof("generating %d census proofs", len(accounts))
 		for _, acc := range accounts {
@@ -286,18 +276,22 @@ func (t *e2eElection) generateProofs(root types.HexBytes, isAnonymousVoting bool
 	}
 
 	pcount := t.config.nvotes / t.config.parallelCount
-	var wg sync.WaitGroup
 	for i := 0; i < len(t.voterAccounts); i += pcount {
 		end := i + pcount
 		if end > len(t.voterAccounts) {
 			end = len(t.voterAccounts)
 		}
 		wg.Add(1)
-		go addNaccounts(t.voterAccounts[i:end], &wg)
+		go addNaccounts(t.voterAccounts[i:end])
 	}
 
 	wg.Wait()
-	stopProofs <- true
+	close(proofCh)
+
+	proofs := make(map[string]*apiclient.CensusProof, len(t.voterAccounts))
+	for p := range proofCh {
+		proofs[p.address] = p.proof
+	}
 
 	log.Debugf("%d/%d census proofs generated successfully", len(proofs), len(t.voterAccounts))