[FAB-16125] fix allow ledger test to succeed when no tests are run

- fixed allow ledger test to succeed when no tests are run.
- extract out initialization and cleanup for couchDB.

Signed-off-by: Chongxin Luo <Chongxin.Luo@ibm.com>

core/ledger/kvledger/txmgmt/privacyenabledstate/db_test.go

@@ -27,7 +27,7 @@ import (
 func TestMain(m *testing.M) {
 	exitCode := m.Run()
 	for _, testEnv := range testEnvs {
-		testEnv.Cleanup()
+		testEnv.StopExternalResource()
 	}
 	os.Exit(exitCode)
 }
@@ -84,6 +84,7 @@ func TestDB(t *testing.T) {
 
 func testDB(t *testing.T, env TestEnv) {
 	env.Init(t)
+	defer env.Cleanup()
 	db := env.GetDBHandle(generateLedgerID(t))
 
 	updates := NewUpdateBatch()
@@ -149,6 +150,7 @@ func TestGetStateMultipleKeys(t *testing.T) {
 
 func testGetStateMultipleKeys(t *testing.T, env TestEnv) {
 	env.Init(t)
+	defer env.Cleanup()
 	db := env.GetDBHandle(generateLedgerID(t))
 
 	updates := NewUpdateBatch()
@@ -191,6 +193,7 @@ func TestGetStateRangeScanIterator(t *testing.T) {
 
 func testGetStateRangeScanIterator(t *testing.T, env TestEnv) {
 	env.Init(t)
+	defer env.Cleanup()
 	db := env.GetDBHandle(generateLedgerID(t))
 
 	updates := NewUpdateBatch()
@@ -251,6 +254,7 @@ func TestQueryOnCouchDB(t *testing.T) {
 
 func testQueryOnCouchDB(t *testing.T, env TestEnv) {
 	env.Init(t)
+	defer env.Cleanup()
 	db := env.GetDBHandle(generateLedgerID(t))
 	updates := NewUpdateBatch()
 
@@ -331,6 +335,7 @@ func TestLongDBNameOnCouchDB(t *testing.T) {
 
 func testLongDBNameOnCouchDB(t *testing.T, env TestEnv) {
 	env.Init(t)
+	defer env.Cleanup()
 
 	// Creates metadataDB (i.e., chainDB)
 	// Allowed pattern for chainName: [a-z][a-z0-9.-]
@@ -441,6 +446,7 @@ func createCollectionConfig(collectionName string) *peer.CollectionConfig {
 
 func testHandleChainCodeDeploy(t *testing.T, env TestEnv) {
 	env.Init(t)
+	defer env.Cleanup()
 	db := env.GetDBHandle(generateLedgerID(t))
 
 	coll1 := createCollectionConfig("collectionMarbles")
@@ -545,6 +551,7 @@ func TestMetadataRetrieval(t *testing.T) {
 
 func testMetadataRetrieval(t *testing.T, env TestEnv) {
 	env.Init(t)
+	defer env.Cleanup()
 	db := env.GetDBHandle(generateLedgerID(t))
 
 	updates := NewUpdateBatch()

core/ledger/kvledger/txmgmt/privacyenabledstate/test_exports.go

@@ -25,10 +25,12 @@ import (
 
 // TestEnv - an interface that a test environment implements
 type TestEnv interface {
+	StartExternalResource()
 	Init(t testing.TB)
 	GetDBHandle(id string) DB
 	GetName() string
 	Cleanup()
+	StopExternalResource()
 }
 
 // Tests will be run against each environment in this array
@@ -69,6 +71,16 @@ func (env *LevelDBCommonStorageTestEnv) Init(t testing.TB) {
 	env.dbPath = dbPath
 }
 
+// StartExternalResource will be an empty implementation for levelDB test environment.
+func (env *LevelDBCommonStorageTestEnv) StartExternalResource() {
+	// empty implementation
+}
+
+// StopExternalResource will be an empty implementation for levelDB test environment.
+func (env *LevelDBCommonStorageTestEnv) StopExternalResource() {
+	// empty implementation
+}
+
 // GetDBHandle implements corresponding function from interface TestEnv
 func (env *LevelDBCommonStorageTestEnv) GetDBHandle(id string) DB {
 	db, err := env.provider.GetDBHandle(id)
@@ -100,6 +112,22 @@ type CouchDBCommonStorageTestEnv struct {
 	couchCleanup      func()
 }
 
+// StartExternalResource starts external couchDB resources.
+func (env *CouchDBCommonStorageTestEnv) StartExternalResource() {
+	if env.couchAddress == "" {
+		env.couchAddress = env.setupCouch()
+	}
+}
+
+// StopExternalResource stops external couchDB resources.
+func (env *CouchDBCommonStorageTestEnv) StopExternalResource() {
+	csdbProvider, _ := env.provider.(*CommonStorageDBProvider)
+	if csdbProvider != nil {
+		statecouchdb.CleanupDB(env.t, csdbProvider.VersionedDBProvider)
+		env.couchCleanup()
+	}
+}
+
 func (env *CouchDBCommonStorageTestEnv) setupCouch() string {
 	externalCouch, set := os.LookupEnv("COUCHDB_ADDR")
 	if set {
@@ -123,9 +151,7 @@ func (env *CouchDBCommonStorageTestEnv) Init(t testing.TB) {
 		t.Fatalf("Failed to create redo log directory: %s", err)
 	}
 
-	if env.couchAddress == "" {
-		env.couchAddress = env.setupCouch()
-	}
+	env.StartExternalResource()
 
 	stateDBConfig := &StateDBConfig{
 		StateDBConfig: &ledger.StateDBConfig{
@@ -173,10 +199,7 @@ func (env *CouchDBCommonStorageTestEnv) GetName() string {
 
 // Cleanup implements corresponding function from interface TestEnv
 func (env *CouchDBCommonStorageTestEnv) Cleanup() {
-	csdbProvider, _ := env.provider.(*CommonStorageDBProvider)
-	statecouchdb.CleanupDB(env.t, csdbProvider.VersionedDBProvider)
 	os.RemoveAll(env.redoPath)
 	env.bookkeeperTestEnv.Cleanup()
 	env.provider.Close()
-	env.couchCleanup()
 }