test: add tests for inbound eviction protection of I2P peers

Author: jonatack

src/test/net_peer_eviction_tests.cpp

@@ -157,6 +157,29 @@ BOOST_AUTO_TEST_CASE(peer_protection_test)
         /* unprotected_peer_ids */ {3, 4, 5, 6, 10, 11},
         random_context));
 
+    // Expect 1/4 I2P peers to be protected from eviction,
+    // if no onion or localhost peers.
+    BOOST_CHECK(IsProtected(
+        num_peers, [](NodeEvictionCandidate& c) {
+            c.m_is_local = false;
+            c.m_network = (c.id == 2 || c.id == 7 || c.id == 10) ? NET_I2P : NET_IPV4;
+        },
+        /* protected_peer_ids */ {2, 7, 10},
+        /* unprotected_peer_ids */ {},
+        random_context));
+
+    // Expect 1/4 I2P peers and 1/4 of the other peers to be protected,
+    // sorted by longest uptime (lowest nTimeConnected), if no onion or localhost peers.
+    BOOST_CHECK(IsProtected(
+        num_peers, [](NodeEvictionCandidate& c) {
+            c.nTimeConnected = c.id;
+            c.m_is_local = false;
+            c.m_network = (c.id == 4 || c.id > 8) ? NET_I2P : NET_IPV6;
+        },
+        /* protected_peer_ids */ {0, 1, 2, 4, 9, 10},
+        /* unprotected_peer_ids */ {3, 5, 6, 7, 8, 11},
+        random_context));
+
     // Tests with 2 networks...
 
     // Combined test: expect having 1 localhost and 1 onion peer out of 4 to