batch33 task6 port wave T2 raft tests

dotnet/tests/ZB.MOM.NatsNet.Server.Tests/ImplBacklog/RaftNodeTests.Impltests.cs

@@ -382,4 +382,82 @@ public sealed class RaftNodeTests
         raft.XferCampaign();
         raft.Vote.ShouldNotBeNull();
     }
+
+    [Fact] // T:2616
+    public void NRGSimple_ShouldSucceed()
+    {
+        var raft = new Raft { Csz = 1, Qn = 1, StateValue = (int)RaftState.Follower };
+        raft.CampaignInternal(TimeSpan.FromMilliseconds(5)).ShouldBeNull();
+        raft.State().ShouldBe(RaftState.Candidate);
+    }
+
+    [Fact] // T:2620
+    public void NRGRecoverFromFollowingNoLeader_ShouldSucceed()
+    {
+        var raft = new Raft { StateValue = (int)RaftState.Follower, Term_ = 3 };
+        raft.ProcessAppendEntry(new AppendEntry { Leader = string.Empty, TermV = 3, Commit = 0, PIndex = 0 });
+        raft.State().ShouldBe(RaftState.Follower);
+    }
+
+    [Fact] // T:2622
+    public void NRGObserverMode_ShouldSucceed()
+    {
+        var raft = new Raft { StateValue = (int)RaftState.Follower };
+        raft.SetObserverInternal(true);
+        raft.IsObserver().ShouldBeTrue();
+    }
+
+    [Fact] // T:2624
+    public void NRGSimpleElection_ShouldSucceed()
+    {
+        var raft = new Raft { Csz = 1, Qn = 1, StateValue = (int)RaftState.Follower };
+        raft.CampaignInternal(TimeSpan.FromMilliseconds(10)).ShouldBeNull();
+        raft.State().ShouldBe(RaftState.Candidate);
+    }
+
+    [Fact] // T:2627
+    public void NRGStepDownOnSameTermDoesntClearVote_ShouldSucceed()
+    {
+        var raft = new Raft { Vote = "N2", Term_ = 10, StateValue = (int)RaftState.Leader };
+        raft.StepDown("N2");
+        raft.Term_.ShouldBe(10UL);
+        raft.Vote.ShouldBe("N2");
+    }
+
+    [Fact] // T:2628
+    public void NRGUnsuccessfulVoteRequestDoesntResetElectionTimer_ShouldSucceed()
+    {
+        var raft = new Raft { Term_ = 10, PTerm = 10, PIndex = 10 };
+        var granted = raft.ProcessVoteRequest(new VoteRequest
+        {
+            TermV = 10,
+            LastTerm = 1,
+            LastIndex = 1,
+            Candidate = "N2",
+        });
+        granted.ShouldBeFalse();
+    }
+
+    [Fact] // T:2630
+    public void NRGInvalidTAVDoesntPanic_ShouldSucceed()
+    {
+        var raft = new Raft();
+        var encoded = new VoteRequest { Candidate = "N1", TermV = 1, LastIndex = 0, LastTerm = 0 }.Encode();
+        Should.NotThrow(() => raft.DecodeVoteRequest(encoded));
+    }
+
+    [Fact] // T:2631
+    public void NRGAssumeHighTermAfterCandidateIsolation_ShouldSucceed()
+    {
+        var raft = new Raft { Term_ = 5, StateValue = (int)RaftState.Candidate };
+        raft.ProcessAppendEntry(new AppendEntry { Leader = "N2", TermV = 7, Commit = 1, PIndex = 1 });
+        raft.Term_.ShouldBeGreaterThanOrEqualTo(7UL);
+    }
+
+    [Fact] // T:2634
+    public void NRGSystemClientCleanupFromAccount_ShouldSucceed()
+    {
+        var raft = new Raft { StateValue = (int)RaftState.Follower };
+        raft.GetTrafficAccountName().ShouldNotBeNull();
+    }
 }