all: get rid of error when creating memory database (#16716)

* all: get rid of error when create mdb

* core: clean up variables definition

* all: inline mdb definition

4 files changed, 16 insertions, 23 deletions

diff --git a/core/state/managed_state_test.go b/core/state/managed_state_test.go
index 1cfdd3a89..3d9c4e867 100644
--- a/core/state/managed_state_test.go
+++ b/core/state/managed_state_test.go
@@ -26,8 +26,7 @@ import (
 var addr = common.BytesToAddress([]byte("test"))
 
 func create() (*ManagedState, *account) {
-	db, _ := ethdb.NewMemDatabase()
-	statedb, _ := New(common.Hash{}, NewDatabase(db))
+	statedb, _ := New(common.Hash{}, NewDatabase(ethdb.NewMemDatabase()))
 	ms := ManageState(statedb)
 	ms.StateDB.SetNonce(addr, 100)
 	ms.accounts[addr] = newAccount(ms.StateDB.getStateObject(addr))
diff --git a/core/state/state_test.go b/core/state/state_test.go
index 6d42d63d8..12778f6f1 100644
--- a/core/state/state_test.go
+++ b/core/state/state_test.go
@@ -87,7 +87,7 @@ func (s *StateSuite) TestDump(c *checker.C) {
 }
 
 func (s *StateSuite) SetUpTest(c *checker.C) {
-	s.db, _ = ethdb.NewMemDatabase()
+	s.db = ethdb.NewMemDatabase()
 	s.state, _ = New(common.Hash{}, NewDatabase(s.db))
 }
 
@@ -133,8 +133,7 @@ func (s *StateSuite) TestSnapshotEmpty(c *checker.C) {
 // use testing instead of checker because checker does not support
 // printing/logging in tests (-check.vv does not work)
 func TestSnapshot2(t *testing.T) {
-	db, _ := ethdb.NewMemDatabase()
-	state, _ := New(common.Hash{}, NewDatabase(db))
+	state, _ := New(common.Hash{}, NewDatabase(ethdb.NewMemDatabase()))
 
 	stateobjaddr0 := toAddr([]byte("so0"))
 	stateobjaddr1 := toAddr([]byte("so1"))
diff --git a/core/state/statedb_test.go b/core/state/statedb_test.go
index 420ca745c..e2b349de8 100644
--- a/core/state/statedb_test.go
+++ b/core/state/statedb_test.go
@@ -39,7 +39,7 @@ import (
 // actually committing the state.
 func TestUpdateLeaks(t *testing.T) {
 	// Create an empty state database
-	db, _ := ethdb.NewMemDatabase()
+	db := ethdb.NewMemDatabase()
 	state, _ := New(common.Hash{}, NewDatabase(db))
 
 	// Update it with some accounts
@@ -66,8 +66,8 @@ func TestUpdateLeaks(t *testing.T) {
 // only the one right before the commit.
 func TestIntermediateLeaks(t *testing.T) {
 	// Create two state databases, one transitioning to the final state, the other final from the beginning
-	transDb, _ := ethdb.NewMemDatabase()
-	finalDb, _ := ethdb.NewMemDatabase()
+	transDb := ethdb.NewMemDatabase()
+	finalDb := ethdb.NewMemDatabase()
 	transState, _ := New(common.Hash{}, NewDatabase(transDb))
 	finalState, _ := New(common.Hash{}, NewDatabase(finalDb))
 
@@ -122,8 +122,7 @@ func TestIntermediateLeaks(t *testing.T) {
 // https://github.com/ethereum/go-ethereum/pull/15549.
 func TestCopy(t *testing.T) {
 	// Create a random state test to copy and modify "independently"
-	db, _ := ethdb.NewMemDatabase()
-	orig, _ := New(common.Hash{}, NewDatabase(db))
+	orig, _ := New(common.Hash{}, NewDatabase(ethdb.NewMemDatabase()))
 
 	for i := byte(0); i < 255; i++ {
 		obj := orig.GetOrNewStateObject(common.BytesToAddress([]byte{i}))
@@ -334,8 +333,7 @@ func (test *snapshotTest) String() string {
 func (test *snapshotTest) run() bool {
 	// Run all actions and create snapshots.
 	var (
-		db, _        = ethdb.NewMemDatabase()
-		state, _     = New(common.Hash{}, NewDatabase(db))
+		state, _     = New(common.Hash{}, NewDatabase(ethdb.NewMemDatabase()))
 		snapshotRevs = make([]int, len(test.snapshots))
 		sindex       = 0
 	)
@@ -426,8 +424,7 @@ func (s *StateSuite) TestTouchDelete(c *check.C) {
 // TestCopyOfCopy tests that modified objects are carried over to the copy, and the copy of the copy.
 // See https://github.com/ethereum/go-ethereum/pull/15225#issuecomment-380191512
 func TestCopyOfCopy(t *testing.T) {
-	db, _ := ethdb.NewMemDatabase()
-	sdb, _ := New(common.Hash{}, NewDatabase(db))
+	sdb, _ := New(common.Hash{}, NewDatabase(ethdb.NewMemDatabase()))
 	addr := common.HexToAddress("aaaa")
 	sdb.SetBalance(addr, big.NewInt(42))
 
diff --git a/core/state/sync_test.go b/core/state/sync_test.go
index 8f14a44e7..317740160 100644
--- a/core/state/sync_test.go
+++ b/core/state/sync_test.go
@@ -38,8 +38,7 @@ type testAccount struct {
 // makeTestState create a sample test state to test node-wise reconstruction.
 func makeTestState() (Database, common.Hash, []*testAccount) {
 	// Create an empty state
-	diskdb, _ := ethdb.NewMemDatabase()
-	db := NewDatabase(diskdb)
+	db := NewDatabase(ethdb.NewMemDatabase())
 	state, _ := New(common.Hash{}, db)
 
 	// Fill it with some arbitrary data
@@ -125,8 +124,7 @@ func checkStateConsistency(db ethdb.Database, root common.Hash) error {
 // Tests that an empty state is not scheduled for syncing.
 func TestEmptyStateSync(t *testing.T) {
 	empty := common.HexToHash("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
-	db, _ := ethdb.NewMemDatabase()
-	if req := NewStateSync(empty, db).Missing(1); len(req) != 0 {
+	if req := NewStateSync(empty, ethdb.NewMemDatabase()).Missing(1); len(req) != 0 {
 		t.Errorf("content requested for empty state: %v", req)
 	}
 }
@@ -141,7 +139,7 @@ func testIterativeStateSync(t *testing.T, batch int) {
 	srcDb, srcRoot, srcAccounts := makeTestState()
 
 	// Create a destination state and sync with the scheduler
-	dstDb, _ := ethdb.NewMemDatabase()
+	dstDb := ethdb.NewMemDatabase()
 	sched := NewStateSync(srcRoot, dstDb)
 
 	queue := append([]common.Hash{}, sched.Missing(batch)...)
@@ -173,7 +171,7 @@ func TestIterativeDelayedStateSync(t *testing.T) {
 	srcDb, srcRoot, srcAccounts := makeTestState()
 
 	// Create a destination state and sync with the scheduler
-	dstDb, _ := ethdb.NewMemDatabase()
+	dstDb := ethdb.NewMemDatabase()
 	sched := NewStateSync(srcRoot, dstDb)
 
 	queue := append([]common.Hash{}, sched.Missing(0)...)
@@ -210,7 +208,7 @@ func testIterativeRandomStateSync(t *testing.T, batch int) {
 	srcDb, srcRoot, srcAccounts := makeTestState()
 
 	// Create a destination state and sync with the scheduler
-	dstDb, _ := ethdb.NewMemDatabase()
+	dstDb := ethdb.NewMemDatabase()
 	sched := NewStateSync(srcRoot, dstDb)
 
 	queue := make(map[common.Hash]struct{})
@@ -250,7 +248,7 @@ func TestIterativeRandomDelayedStateSync(t *testing.T) {
 	srcDb, srcRoot, srcAccounts := makeTestState()
 
 	// Create a destination state and sync with the scheduler
-	dstDb, _ := ethdb.NewMemDatabase()
+	dstDb := ethdb.NewMemDatabase()
 	sched := NewStateSync(srcRoot, dstDb)
 
 	queue := make(map[common.Hash]struct{})
@@ -297,7 +295,7 @@ func TestIncompleteStateSync(t *testing.T) {
 	checkTrieConsistency(srcDb.TrieDB().DiskDB().(ethdb.Database), srcRoot)
 
 	// Create a destination state and sync with the scheduler
-	dstDb, _ := ethdb.NewMemDatabase()
+	dstDb := ethdb.NewMemDatabase()
 	sched := NewStateSync(srcRoot, dstDb)
 
 	added := []common.Hash{}