From b1da201d76359569fc4b455a4464f43ab525dbe7 Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Fri, 29 Sep 2023 00:49:24 +0300
Subject: [PATCH] Add initialTerm to testAdd and make it fail; add a failing
 testRestart

---
 tinyraft.spec.js | 54 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

diff --git a/tinyraft.spec.js b/tinyraft.spec.js
index 9da77bf..c3a273b 100644
--- a/tinyraft.spec.js
+++ b/tinyraft.spec.js
@@ -132,7 +132,7 @@ async function testStartThenRemoveNode()
 async function testAddNode()
 {
     console.log('testAddNode');
-    const nodes = newNodes(5);
+    const nodes = newNodes(5, {}, cfg => cfg.initialTerm = 1000);
     await new Promise(ok => setTimeout(ok, 2000));
     checkQuorum(nodes, 5);
     // Add node
@@ -180,11 +180,63 @@ async function testLeadershipExpiration()
     console.log('testLeadershipExpiration: OK');
 }
 
+async function testRestart()
+{
+    const nodes = newNodes(5, {}, cfg => cfg.initialTerm = 1000);
+    let leaderChanges = 0, prevLeader = null;
+    nodes[2].on('change', (st) =>
+    {
+        const leader = st.state == TinyRaft.CANDIDATE ? null : st.leader;
+        if (leader != prevLeader)
+        {
+            prevLeader = leader;
+            leaderChanges++;
+        }
+    });
+    // Check that 5 nodes are in quorum after 2000ms
+    await new Promise(ok => setTimeout(ok, 2000));
+    checkQuorum(nodes, 5);
+    if (leaderChanges >= 3)
+    {
+        throw new Error("leaderChanges = "+leaderChanges+" (expected < 3)")
+    }
+    // Stop a follower
+    let restarted = 1 + (prevLeader % 5);
+    if (restarted == 2)
+    {
+        restarted = 1 + (prevLeader + 1) % 5;
+    }
+    console.log("stopping a follower (node "+restarted+")");
+    nodes[restarted].stop();
+    delete nodes[restarted];
+    // Wait 2000ms
+    await new Promise(ok => setTimeout(ok, 2000));
+    // Restart a follower
+    console.log("restarting a follower (node "+restarted+")");
+    leaderChanges = 0;
+    newNode(restarted, nodes, {}, null);
+    nodes[restarted].start();
+    // Check quorum and the fact that the leader didn't change after 2000ms
+    await new Promise(ok => setTimeout(ok, 2000));
+    checkQuorum(nodes, 5);
+    if (leaderChanges > 0)
+    {
+        throw new Error("leader changed after restart of a follower");
+    }
+    // Clean up
+    for (const id in nodes)
+    {
+        nodes[id].stop();
+    }
+    console.log('testRestart: OK');
+}
+
 async function run()
 {
     await testStartThenRemoveNode();
     await testAddNode();
     await testLeadershipExpiration();
+    await testRestart();
     process.exit(0);
 }