3 files changed, 15 insertions, 8 deletions
diff --git a/core/test/blocks-generator.go b/core/test/blocks-generator.go
index 3cd97ee..b05d08f 100644
--- a/core/test/blocks-generator.go
+++ b/core/test/blocks-generator.go
@@ -236,7 +236,8 @@ func (gen *BlocksGenerator) Generate(
 	validatorCount int,
 	blockCount int,
 	ackingCountGenerator func() int,
-	writer blockdb.Writer) (err error) {
+	writer blockdb.Writer) (
+	validators types.ValidatorIDs, err error) {
 
 	if ackingCountGenerator == nil {
 		ackingCountGenerator = normalAckingCountGenerator(
@@ -244,7 +245,7 @@ func (gen *BlocksGenerator) Generate(
 			float64(validatorCount/2),
 			float64(validatorCount/4+1))
 	}
-	validators := []types.ValidatorID{}
+	validators = types.ValidatorIDs{}
 	for i := 0; i < validatorCount; i++ {
 		validators = append(
 			validators, types.ValidatorID{Hash: common.NewRandomHash()})
diff --git a/core/test/blocks-generator_test.go b/core/test/blocks-generator_test.go
index 43e994f..5c85fbd 100644
--- a/core/test/blocks-generator_test.go
+++ b/core/test/blocks-generator_test.go
@@ -39,9 +39,10 @@ func (s *BlocksGeneratorTestCase) TestGenerate() {
 	db, err := blockdb.NewMemBackedBlockDB()
 	s.Require().Nil(err)
 
-	err = gen.Generate(
+	validators, err := gen.Generate(
 		validatorCount, blockCount, nil, db)
 	s.Require().Nil(err)
+	s.Require().Len(validators, validatorCount)
 
 	// Load all blocks in that database for further checking.
 	iter, err := db.GetAll()
@@ -114,8 +115,10 @@ func (s *BlocksGeneratorTestCase) TestGenerateWithMaxAckCount() {
 	// Generate with 0 acks.
 	db, err := blockdb.NewMemBackedBlockDB()
 	req.Nil(err)
-	req.Nil(gen.Generate(
-		validatorCount, blockCount, MaxAckingCountGenerator(0), db))
+	validators, err := gen.Generate(
+		validatorCount, blockCount, MaxAckingCountGenerator(0), db)
+	req.Nil(err)
+	req.Len(validators, validatorCount)
 	// Load blocks to check their acking count.
 	iter, err := db.GetAll()
 	req.Nil(err)
@@ -134,9 +137,11 @@ func (s *BlocksGeneratorTestCase) TestGenerateWithMaxAckCount() {
 	// Generate with acks as many as possible.
 	db, err = blockdb.NewMemBackedBlockDB()
 	req.Nil(err)
-	req.Nil(gen.Generate(
+	validators, err = gen.Generate(
 		validatorCount, blockCount, MaxAckingCountGenerator(
-			validatorCount), db))
+			validatorCount), db)
+	req.Nil(err)
+	req.Len(validators, validatorCount)
 	// Load blocks to verify the average acking count.
 	totalAckingCount := 0
 	totalBlockCount := 0
diff --git a/core/test/revealer_test.go b/core/test/revealer_test.go
index 8087136..032cab3 100644
--- a/core/test/revealer_test.go
+++ b/core/test/revealer_test.go
@@ -45,9 +45,10 @@ func (s *RevealerTestSuite) SetupSuite() {
 
 	// Randomly generate blocks.
 	gen := NewBlocksGenerator(nil, stableRandomHash)
-	err = gen.Generate(
+	validators, err := gen.Generate(
 		validatorCount, blockCount, nil, s.db)
 	s.Require().Nil(err)
+	s.Require().Len(validators, validatorCount)
 
 	// Cache the count of total generated block.
 	iter, err := s.db.GetAll()