Fix agreement test

election/agreement.go

 package election
 
 import (
+	"errors"
 	"fmt"
 	"log"
 	"sync"
@@ -53,6 +54,9 @@ func (a *Agreement) TallyList() ([]uuid.UUID, error) {
 
 	// Find the maximum subset
 	hashes := MaxSubset(a.required, bls)
+	if len(hashes) == 0 {
+		return nil, errors.New("cannot agree on ballots")
+	}
 
 	// We know create a list of ballots we have in the subset.
 	list := make([]uuid.UUID, 0, len(a.ourList))

election/election_test.go

@@ -257,10 +257,15 @@ func TestCloseAgreement(t *testing.T) {
 	_ = testElection(t, PhaseTallying, func(e *Election) <-chan time.Time {
 		e.Status.Phase = PhaseCollect
 
-		ballots := CreateBallots(3, createXS(1), big.NewInt(1))
+		ballots := CreateBallots(3, createXS(3), big.NewInt(1))
 		e.handleBallot(UniqueID(strconv.Itoa(1)), ballots["1"])
 
 		e.handleClosing("2")
+
+		b := ballots["2"]
+		_ = e.Agreement.AddList("2", map[string]uuid.UUID{
+			b.Hash(): b.ID,
+		})
 		e.handleClosing("3")
 
 		return time.After(100 * time.Millisecond)
@@ -285,12 +290,16 @@ func TestTallyDeadline(t *testing.T) {
 		e.Deadline = time.Now().Add(1 * time.Second)
 		_ = e.Start()
 
-		ballots := CreateBallots(3, createXS(1), big.NewInt(1))
+		ballots := CreateBallots(3, createXS(3), big.NewInt(1))
 		e.handleBallot(UniqueID(strconv.Itoa(1)), ballots["1"])
 
 		// By closing another server, we should go directly to tallying when
 		// deadline is reached
 		e.handleClosing("2")
+		b := ballots["2"]
+		_ = e.Agreement.AddList("2", map[string]uuid.UUID{
+			b.Hash(): b.ID,
+		})
 
 		return time.After(1200 * time.Millisecond)
 	})
@@ -319,9 +328,13 @@ func TestTallyAfterClose(t *testing.T) {
 		e.Deadline = time.Now().Add(1000 * time.Millisecond)
 		_ = e.Start()
 
-		ballots := CreateBallots(3, createXS(1), big.NewInt(1))
+		ballots := CreateBallots(3, createXS(3), big.NewInt(1))
 		e.handleBallot(UniqueID(strconv.Itoa(1)), ballots["1"])
 
+		b := ballots["2"]
+		_ = e.Agreement.AddList("2", map[string]uuid.UUID{
+			b.Hash(): b.ID,
+		})
 		e.handleClosing("2")
 
 		return time.After(1200 * time.Millisecond)
@@ -354,6 +367,9 @@ func TestHandleTally(t *testing.T) {
 		Share:   ballots["4"].Share,
 		Commits: ballots["4"].Commits,
 	}
+	ballotList := map[string]uuid.UUID{
+		ballots["1"].Hash(): ballots["1"].ID,
+	}
 
 	_ = testElection(t, PhaseResult, func(e *Election) <-chan time.Time {
 		e.Status.Phase = PhaseCollect
@@ -363,7 +379,9 @@ func TestHandleTally(t *testing.T) {
 		if e.tallyBox.Size() != 0 {
 			t.Errorf("Expected 0 tally, got %d", e.tallyBox.Size())
 		}
+
 		e.handleClosing("2")
+		_ = e.Agreement.AddList("2", ballotList)
 
 		e.handleTally("2", tally1)
 		e.handleTally("2", tally1)
@@ -372,6 +390,7 @@ func TestHandleTally(t *testing.T) {
 		}
 
 		e.handleClosing("3")
+		_ = e.Agreement.AddList("3", ballotList)
 		e.handleTally("3", tally2)
 
 		return time.After(500 * time.Millisecond)
@@ -399,9 +418,11 @@ func TestCloseTimeoutTally(t *testing.T) {
 		e.Status.Phase = PhaseCollect
 		e.Config.CloseSleep = 1 * time.Second
 
-		ballots := CreateBallots(3, createXS(1), big.NewInt(1))
+		ballots := CreateBallots(3, createXS(3), big.NewInt(1))
 		e.handleBallot(UniqueID(strconv.Itoa(1)), ballots["1"])
-		e.handleClosing("3")
+
+		_ = e.Agreement.AddList("2", map[string]uuid.UUID{ballots["2"].Hash(): ballots["2"].ID})
+		e.handleClosing("2")
 
 		// This should start a go-routine waiting for late ballots
 		e.nextPhase(ReasonAgreement)
@@ -409,7 +430,8 @@ func TestCloseTimeoutTally(t *testing.T) {
 		// This prevent us from wait for ballot lists
 		e.Config.CloseSleep = 0
 
-		e.handleClosing("4")
+		_ = e.Agreement.AddList("3", map[string]uuid.UUID{ballots["3"].Hash(): ballots["3"].ID})
+		e.handleClosing("3")
 		if e.Status.Phase != PhaseCloseWait {
 			t.Errorf("Not waiting for late ballots")
 		}