From 42c81d57f055650c7618b5295d3b0d2bd36a39e0 Mon Sep 17 00:00:00 2001
From: gr0vity <gr0vity.dev@gmail.com>
Date: Sun, 1 Dec 2024 15:10:59 +0100
Subject: [PATCH] add testcase for
 election_scheduler.transition_optimistic_to_priority

---
 nano/core_test/election_scheduler.cpp | 38 +++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/nano/core_test/election_scheduler.cpp b/nano/core_test/election_scheduler.cpp
index cd2d642ed6..472014544e 100644
--- a/nano/core_test/election_scheduler.cpp
+++ b/nano/core_test/election_scheduler.cpp
@@ -4,6 +4,7 @@
 #include <nano/node/scheduler/component.hpp>
 #include <nano/node/scheduler/priority.hpp>
 #include <nano/secure/ledger.hpp>
+#include <nano/test_common/chains.hpp>
 #include <nano/test_common/system.hpp>
 #include <nano/test_common/testutil.hpp>
 
@@ -157,6 +158,43 @@ TEST (election_scheduler, activate_one_flush)
 	ASSERT_TIMELY (5s, node.active.election (send1->qualified_root ()));
 }
 
+
+TEST (election_scheduler, transition_optimistic_to_priority)
+{
+       nano::test::system system;
+       nano::node_config config = system.default_config ();
+       config.optimistic_scheduler.gap_threshold = 1;
+       auto & node = *system.add_node (config);
+
+       // Create a chain of blocks
+       const int howmany_blocks = 2;
+       auto chains = nano::test::setup_chains (system, node, /* single chain */ 1, howmany_blocks, nano::dev::genesis_key, /* do not confirm */ false);
+       auto & [account, blocks] = chains.front ();
+
+       // Priority election is created for the first block in chain
+       ASSERT_TIMELY (1s, node.active.size () == 1);
+
+       // Wait for the optimistic election to start
+       auto const & block = blocks.back ();
+       ASSERT_TIMELY (5s, node.vote_router.active (block->hash ()));
+       auto election = node.active.election (block->qualified_root ());
+       ASSERT_EQ (election->behavior (), nano::election_behavior::optimistic);
+       ASSERT_EQ (node.active.size (), 2);
+
+       // Confirm block prior to the optimitic election
+       nano::test::confirm (node.ledger, blocks.at (howmany_blocks - 1));
+
+       // Now activate a priority election for the same block
+       auto secure_transaction (node.ledger.tx_begin_read ());
+       node.scheduler.priority.activate (secure_transaction, nano::dev::genesis_key.pub);
+
+       // Verify the election was upgraded to priority
+       ASSERT_TIMELY (5s, election->behavior () == nano::election_behavior::priority);
+
+       // Verify the election is still active and properly transitioned
+       ASSERT_TRUE (node.active.active (*block));
+}
+
 /**
  * Tests that the election scheduler and the active transactions container (AEC)
  * work in sync with regards to the node configuration value "active_elections.size".