ClientReconnectTest flaky test fix (hazelcast#1053)

* Add client version check

* Add version check for all reconnect tests

* Fix flaky ClientReconnectTest

* Adjust comment

* Delete version check

* Delete unused import

test/integration/backward_compatible/ClientReconnectTest.js

@@ -18,7 +18,7 @@
 const { expect } = require('chai');
 const RC = require('../RC');
 const { Client } = require('../../../');
-const { markClientVersionAtLeast } = require('../../TestUtil');
+const { isClientVersionAtLeast, assertTrueEventually } = require('../../TestUtil');
 
 /**
  * Basic tests for reconnection to cluster scenarios.
@@ -27,6 +27,28 @@ describe('ClientReconnectTest', function () {
     let cluster;
     let client;
 
+    /**
+     * Waits for disconnection. getMap(), map.put() messages are not retryable. If terminateMember does not
+     * close the client connection immediately it is possible for the client to realize that later when map.put
+     * or getMap invocation started. In that case, the connection will be closed with TargetDisconnectedError.
+     * Because these client messages are not retryable, the invocation will be rejected with an error, leading
+     * to flaky tests. To avoid that, this function will wait for the connections count to be zero.
+     */
+    const waitForDisconnection = async (client) => {
+        let getConnectionsFn;
+        if (isClientVersionAtLeast('4.2')) {
+            const clientRegistry = client.connectionRegistry;
+            getConnectionsFn = clientRegistry.getConnections.bind(clientRegistry);
+        } else {
+            const connManager = client.getConnectionManager();
+            getConnectionsFn = connManager.getActiveConnections.bind(connManager);
+        }
+
+        await assertTrueEventually(async () => {
+            expect(getConnectionsFn()).to.be.empty;
+        });
+    };
+
     beforeEach(function () {
        client = undefined;
        cluster = undefined;
@@ -54,6 +76,7 @@ describe('ClientReconnectTest', function () {
         const map = await client.getMap('test');
 
         await RC.terminateMember(cluster.id, member.uuid);
+        await waitForDisconnection(client);
         await RC.startMember(cluster.id);
 
         await map.put('testkey', 'testvalue');
@@ -76,6 +99,7 @@ describe('ClientReconnectTest', function () {
         });
         const map = await client.getMap('test');
         await RC.terminateMember(cluster.id, member.uuid);
+        await waitForDisconnection(client);
 
         const promise = map.put('testkey', 'testvalue').then(() => {
             return map.get('testkey');
@@ -89,9 +113,6 @@ describe('ClientReconnectTest', function () {
     });
 
     it('create proxy while member is down, member comes back', async function () {
-        // Before https://github.com/hazelcast/hazelcast-nodejs-client/pull/704, this test is flaky.
-        // https://github.com/hazelcast/hazelcast-nodejs-client/issues/658#issuecomment-868970776
-        markClientVersionAtLeast(this, '4.0.2');
         cluster = await RC.createCluster(null, null);
         const member = await RC.startMember(cluster.id);
         client = await Client.newHazelcastClient({
@@ -102,6 +123,7 @@ describe('ClientReconnectTest', function () {
             }
         });
         await RC.terminateMember(cluster.id, member.uuid);
+        await waitForDisconnection(client);
 
         let map;