test: check for grade incarnations in tests

test/conftest.py

@@ -214,6 +214,9 @@ class Instance:
     def listen(self):
         return f"{self.host}:{self.port}"
 
+    def current_grade(self):
+        return self.call("picolib.peer_info", self.instance_id)["current_grade"]
+
     def instance_uuid(self):
         return self.eval("return box.info.uuid")
 

test/int/test_couple.py

@@ -59,11 +59,18 @@ def test_restart_follower(cluster2: Cluster):
     # Then it's able to start and remain a follower
 
     i1, i2 = cluster2.instances
+    assert i1.current_grade() == dict(variant="Online", incarnation=1)
+    assert i2.current_grade() == dict(variant="Online", incarnation=1)
     i2.restart()
     i2.wait_online()
+    assert i2.current_grade() == dict(variant="Online", incarnation=2)
     i1.assert_raft_status("Leader")
     i2.assert_raft_status("Follower")
 
+    i2.restart()
+    i2.wait_online()
+    assert i2.current_grade() == dict(variant="Online", incarnation=3)
+
 
 def test_restart_leader(cluster2: Cluster):
     # Given a cluster of two instances - i1 (leader) and i2 (follower)
@@ -72,10 +79,16 @@ def test_restart_leader(cluster2: Cluster):
     # No assuptions about leadership are made though.
 
     i1, _ = cluster2.instances
+    assert i1.current_grade() == dict(variant="Online", incarnation=1)
     i1.restart()
     i1.wait_online()
+    assert i1.current_grade() == dict(variant="Online", incarnation=2)
     i1.raft_propose_eval("return")
 
+    i1.restart()
+    i1.wait_online()
+    assert i1.current_grade() == dict(variant="Online", incarnation=3)
+
 
 def test_restart_both(cluster2: Cluster):
     # Given a cluster of 2 instances - i1, i2
@@ -83,6 +96,8 @@ def test_restart_both(cluster2: Cluster):
     # Then both can become ready and handle proposals.
 
     i1, i2 = cluster2.instances
+    assert i1.current_grade() == dict(variant="Online", incarnation=1)
+    assert i2.current_grade() == dict(variant="Online", incarnation=1)
     i1.terminate()
     i2.terminate()
 
@@ -98,7 +113,9 @@ def test_restart_both(cluster2: Cluster):
     i2.start()
 
     i1.wait_online()
+    assert i1.current_grade() == dict(variant="Online", incarnation=2)
     i2.wait_online()
+    assert i1.current_grade() == dict(variant="Online", incarnation=2)
 
     i1.raft_propose_eval("rawset(_G, 'check', true)")
     assert i1.eval("return check") is True