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

5 files changed, 25 insertions, 38 deletions

diff --git a/trie/iterator_test.go b/trie/iterator_test.go
index dce1c78b5..2a510b1c2 100644
--- a/trie/iterator_test.go
+++ b/trie/iterator_test.go
@@ -289,7 +289,7 @@ func TestIteratorContinueAfterErrorDisk(t *testing.T)    { testIteratorContinueA
 func TestIteratorContinueAfterErrorMemonly(t *testing.T) { testIteratorContinueAfterError(t, true) }
 
 func testIteratorContinueAfterError(t *testing.T, memonly bool) {
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
 
 	tr, _ := New(common.Hash{}, triedb)
@@ -376,7 +376,7 @@ func TestIteratorContinueAfterSeekErrorMemonly(t *testing.T) {
 
 func testIteratorContinueAfterSeekError(t *testing.T, memonly bool) {
 	// Commit test trie to db, then remove the node containing "bars".
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
 
 	ctr, _ := New(common.Hash{}, triedb)
diff --git a/trie/proof_test.go b/trie/proof_test.go
index fff313d7f..a3537787c 100644
--- a/trie/proof_test.go
+++ b/trie/proof_test.go
@@ -36,7 +36,7 @@ func TestProof(t *testing.T) {
 	trie, vals := randomTrie(500)
 	root := trie.Hash()
 	for _, kv := range vals {
-		proofs, _ := ethdb.NewMemDatabase()
+		proofs := ethdb.NewMemDatabase()
 		if trie.Prove(kv.k, 0, proofs) != nil {
 			t.Fatalf("missing key %x while constructing proof", kv.k)
 		}
@@ -53,7 +53,7 @@ func TestProof(t *testing.T) {
 func TestOneElementProof(t *testing.T) {
 	trie := new(Trie)
 	updateString(trie, "k", "v")
-	proofs, _ := ethdb.NewMemDatabase()
+	proofs := ethdb.NewMemDatabase()
 	trie.Prove([]byte("k"), 0, proofs)
 	if len(proofs.Keys()) != 1 {
 		t.Error("proof should have one element")
@@ -71,7 +71,7 @@ func TestVerifyBadProof(t *testing.T) {
 	trie, vals := randomTrie(800)
 	root := trie.Hash()
 	for _, kv := range vals {
-		proofs, _ := ethdb.NewMemDatabase()
+		proofs := ethdb.NewMemDatabase()
 		trie.Prove(kv.k, 0, proofs)
 		if len(proofs.Keys()) == 0 {
 			t.Fatal("zero length proof")
@@ -109,7 +109,7 @@ func BenchmarkProve(b *testing.B) {
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		kv := vals[keys[i%len(keys)]]
-		proofs, _ := ethdb.NewMemDatabase()
+		proofs := ethdb.NewMemDatabase()
 		if trie.Prove(kv.k, 0, proofs); len(proofs.Keys()) == 0 {
 			b.Fatalf("zero length proof for %x", kv.k)
 		}
@@ -123,7 +123,7 @@ func BenchmarkVerifyProof(b *testing.B) {
 	var proofs []*ethdb.MemDatabase
 	for k := range vals {
 		keys = append(keys, k)
-		proof, _ := ethdb.NewMemDatabase()
+		proof := ethdb.NewMemDatabase()
 		trie.Prove([]byte(k), 0, proof)
 		proofs = append(proofs, proof)
 	}
diff --git a/trie/secure_trie_test.go b/trie/secure_trie_test.go
index aedf5a1cd..d16d99968 100644
--- a/trie/secure_trie_test.go
+++ b/trie/secure_trie_test.go
@@ -28,18 +28,14 @@ import (
 )
 
 func newEmptySecure() *SecureTrie {
-	diskdb, _ := ethdb.NewMemDatabase()
-	triedb := NewDatabase(diskdb)
-
-	trie, _ := NewSecure(common.Hash{}, triedb, 0)
+	trie, _ := NewSecure(common.Hash{}, NewDatabase(ethdb.NewMemDatabase()), 0)
 	return trie
 }
 
 // makeTestSecureTrie creates a large enough secure trie for testing.
 func makeTestSecureTrie() (*Database, *SecureTrie, map[string][]byte) {
 	// Create an empty trie
-	diskdb, _ := ethdb.NewMemDatabase()
-	triedb := NewDatabase(diskdb)
+	triedb := NewDatabase(ethdb.NewMemDatabase())
 
 	trie, _ := NewSecure(common.Hash{}, triedb, 0)
 
diff --git a/trie/sync_test.go b/trie/sync_test.go
index 4a720612b..142a6f5b1 100644
--- a/trie/sync_test.go
+++ b/trie/sync_test.go
@@ -27,8 +27,7 @@ import (
 // makeTestTrie create a sample test trie to test node-wise reconstruction.
 func makeTestTrie() (*Database, *Trie, map[string][]byte) {
 	// Create an empty trie
-	diskdb, _ := ethdb.NewMemDatabase()
-	triedb := NewDatabase(diskdb)
+	triedb := NewDatabase(ethdb.NewMemDatabase())
 	trie, _ := New(common.Hash{}, triedb)
 
 	// Fill it with some arbitrary data
@@ -89,18 +88,13 @@ func checkTrieConsistency(db *Database, root common.Hash) error {
 
 // Tests that an empty trie is not scheduled for syncing.
 func TestEmptyTrieSync(t *testing.T) {
-	diskdbA, _ := ethdb.NewMemDatabase()
-	triedbA := NewDatabase(diskdbA)
-
-	diskdbB, _ := ethdb.NewMemDatabase()
-	triedbB := NewDatabase(diskdbB)
-
-	emptyA, _ := New(common.Hash{}, triedbA)
-	emptyB, _ := New(emptyRoot, triedbB)
+	dbA := NewDatabase(ethdb.NewMemDatabase())
+	dbB := NewDatabase(ethdb.NewMemDatabase())
+	emptyA, _ := New(common.Hash{}, dbA)
+	emptyB, _ := New(emptyRoot, dbB)
 
 	for i, trie := range []*Trie{emptyA, emptyB} {
-		diskdb, _ := ethdb.NewMemDatabase()
-		if req := NewTrieSync(trie.Hash(), diskdb, nil).Missing(1); len(req) != 0 {
+		if req := NewTrieSync(trie.Hash(), ethdb.NewMemDatabase(), nil).Missing(1); len(req) != 0 {
 			t.Errorf("test %d: content requested for empty trie: %v", i, req)
 		}
 	}
@@ -116,7 +110,7 @@ func testIterativeTrieSync(t *testing.T, batch int) {
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
 	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
 
@@ -149,7 +143,7 @@ func TestIterativeDelayedTrieSync(t *testing.T) {
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
 	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
 
@@ -187,7 +181,7 @@ func testIterativeRandomTrieSync(t *testing.T, batch int) {
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
 	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
 
@@ -228,7 +222,7 @@ func TestIterativeRandomDelayedTrieSync(t *testing.T) {
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
 	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
 
@@ -275,7 +269,7 @@ func TestDuplicateAvoidanceTrieSync(t *testing.T) {
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
 	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
 
@@ -315,7 +309,7 @@ func TestIncompleteTrieSync(t *testing.T) {
 	srcDb, srcTrie, _ := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
 	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
 
diff --git a/trie/trie_test.go b/trie/trie_test.go
index 997222628..f8e5fd12a 100644
--- a/trie/trie_test.go
+++ b/trie/trie_test.go
@@ -43,8 +43,7 @@ func init() {
 
 // Used for testing
 func newEmpty() *Trie {
-	diskdb, _ := ethdb.NewMemDatabase()
-	trie, _ := New(common.Hash{}, NewDatabase(diskdb))
+	trie, _ := New(common.Hash{}, NewDatabase(ethdb.NewMemDatabase()))
 	return trie
 }
 
@@ -68,8 +67,7 @@ func TestNull(t *testing.T) {
 }
 
 func TestMissingRoot(t *testing.T) {
-	diskdb, _ := ethdb.NewMemDatabase()
-	trie, err := New(common.HexToHash("0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33"), NewDatabase(diskdb))
+	trie, err := New(common.HexToHash("0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33"), NewDatabase(ethdb.NewMemDatabase()))
 	if trie != nil {
 		t.Error("New returned non-nil trie for invalid root")
 	}
@@ -82,7 +80,7 @@ func TestMissingNodeDisk(t *testing.T)    { testMissingNode(t, false) }
 func TestMissingNodeMemonly(t *testing.T) { testMissingNode(t, true) }
 
 func testMissingNode(t *testing.T, memonly bool) {
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
 
 	trie, _ := New(common.Hash{}, triedb)
@@ -413,8 +411,7 @@ func (randTest) Generate(r *rand.Rand, size int) reflect.Value {
 }
 
 func runRandTest(rt randTest) bool {
-	diskdb, _ := ethdb.NewMemDatabase()
-	triedb := NewDatabase(diskdb)
+	triedb := NewDatabase(ethdb.NewMemDatabase())
 
 	tr, _ := New(common.Hash{}, triedb)
 	values := make(map[string]string) // tracks content of the trie