test: adding test for the invalid decided just

consensus/cp_decide.go

@@ -38,7 +38,6 @@ func (s *cpDecideState) decide() {
 			}
 			s.signAddCPDecidedVote(*s.cpWeakValidity, s.cpRound, vote.CPValueZero, just)
 			s.cpDecide(vote.CPValueZero)
-			s.cpDecided = 0
 		} else {
 			// conflicting votes
 			s.logger.Debug("conflicting main votes", "round", s.cpRound)

consensus/cp_test.go

@@ -443,3 +443,34 @@ func TestInvalidJustMainVoteConflict(t *testing.T) {
 		})
 	})
 }
+
+func TestInvalidJustDecided(t *testing.T) {
+	td := setup(t)
+
+	td.enterNewHeight(td.consX)
+	h := uint32(1)
+	r := int16(0)
+	just := &vote.JustDecided{
+		QCert: td.GenerateTestCertificate(h),
+	}
+
+	t.Run("invalid value: abstain", func(t *testing.T) {
+		v := vote.NewCPDecidedVote(td.RandHash(), h, r, 0, vote.CPValueAbstain, just, td.consB.valKey.Address())
+
+		err := td.consX.changeProposer.checkJust(v)
+		assert.ErrorIs(t, err, invalidJustificationError{
+			JustType: just.Type(),
+			Reason:   "invalid value: abstain",
+		})
+	})
+
+	t.Run("invalid certificate", func(t *testing.T) {
+		v := vote.NewCPDecidedVote(td.RandHash(), h, r, 0, vote.CPValueOne, just, td.consB.valKey.Address())
+
+		err := td.consX.changeProposer.checkJust(v)
+		assert.ErrorIs(t, err, invalidJustificationError{
+			JustType: just.Type(),
+			Reason:   fmt.Sprintf("certificate has an unexpected committers: %v", just.QCert.Committers()),
+		})
+	})
+}