diff --git a/src/test/app/LedgerHistory_test.cpp b/src/test/app/LedgerHistory_test.cpp
index 93ab4a6210..a408991497 100644
--- a/src/test/app/LedgerHistory_test.cpp
+++ b/src/test/app/LedgerHistory_test.cpp
@@ -67,6 +67,67 @@ public:
         return res;
     }
 
+    void
+    testHashIndexInvariant()
+    {
+        testcase("LedgerHistory hash/index invariant");
+        using namespace jtx;
+        using namespace std::chrono;
+
+        Env env{*this};
+        LedgerHistory lh{beast::insight::NullCollector::New(), env.app()};
+
+        // Create and insert validated ledgers
+        auto const genesis = makeLedger({}, env, lh, 0s);
+        auto const ledger1 = makeLedger(genesis, env, lh, 4s);
+        auto const ledger2 = makeLedger(ledger1, env, lh, 4s);
+        auto const ledger3 = makeLedger(ledger2, env, lh, 4s);
+
+        // Insert as validated (so they go into by_index)
+        lh.insert(genesis, true);
+        lh.insert(ledger1, true);
+        lh.insert(ledger2, true);
+        lh.insert(ledger3, true);
+
+        // Verify the hash/index invariant holds
+        // Can retrieve by sequence and get correct hash
+        BEAST_EXPECT(lh.getLedgerHash(genesis->header().seq) == genesis->header().hash);
+        BEAST_EXPECT(lh.getLedgerHash(ledger1->header().seq) == ledger1->header().hash);
+        BEAST_EXPECT(lh.getLedgerHash(ledger2->header().seq) == ledger2->header().hash);
+        BEAST_EXPECT(lh.getLedgerHash(ledger3->header().seq) == ledger3->header().hash);
+
+        // Can retrieve by sequence and get correct ledger
+        auto fetched1 = lh.getLedgerBySeq(ledger1->header().seq);
+        BEAST_EXPECT(fetched1 != nullptr);
+        BEAST_EXPECT(fetched1->header().hash == ledger1->header().hash);
+
+        auto fetched2 = lh.getLedgerBySeq(ledger2->header().seq);
+        BEAST_EXPECT(fetched2 != nullptr);
+        BEAST_EXPECT(fetched2->header().hash == ledger2->header().hash);
+
+        // Clear ledgers prior to ledger2's sequence
+        lh.clearLedgerCachePrior(ledger2->header().seq);
+
+        // Verify old entries are gone from the in-memory by_index map
+        // Note: getLedgerHash checks by_index directly without DB fallback
+        BEAST_EXPECT(lh.getLedgerHash(genesis->header().seq).isZero());
+        BEAST_EXPECT(lh.getLedgerHash(ledger1->header().seq).isZero());
+
+        // Verify newer entries are still present in by_index
+        BEAST_EXPECT(lh.getLedgerHash(ledger2->header().seq) == ledger2->header().hash);
+        BEAST_EXPECT(lh.getLedgerHash(ledger3->header().seq) == ledger3->header().hash);
+
+        // Verify newer entries remain retrievable and consistent
+        // getLedgerBySeq uses by_index first, then falls back to DB if needed
+        auto fetched2After = lh.getLedgerBySeq(ledger2->header().seq);
+        BEAST_EXPECT(fetched2After != nullptr);
+        BEAST_EXPECT(fetched2After->header().hash == ledger2->header().hash);
+
+        auto fetched3After = lh.getLedgerBySeq(ledger3->header().seq);
+        BEAST_EXPECT(fetched3After != nullptr);
+        BEAST_EXPECT(fetched3After->header().hash == ledger3->header().hash);
+    }
+
     void
     testHandleMismatch()
     {
@@ -163,6 +224,7 @@ public:
     void
     run() override
     {
+        testHashIndexInvariant();
         testHandleMismatch();
     }
 };
diff --git a/src/test/basics/TaggedCache_test.cpp b/src/test/basics/TaggedCache_test.cpp
index 78dc25380b..6d4c3198ba 100644
--- a/src/test/basics/TaggedCache_test.cpp
+++ b/src/test/basics/TaggedCache_test.cpp
@@ -20,6 +20,13 @@ original object.
 class TaggedCache_test : public beast::unit_test::suite
 {
 public:
+    // Mutable value type for testing fetch_and_modify
+    struct MutableValue
+    {
+        int counter = 0;
+        std::string name;
+    };
+
     void
     run() override
     {
@@ -129,6 +136,54 @@ public:
             BEAST_EXPECT(c.getCacheSize() == 0);
             BEAST_EXPECT(c.getTrackSize() == 0);
         }
+
+        // Test fetch_and_modify: insert on miss, modify on hit
+        {
+            using MutCache = TaggedCache<Key, MutableValue>;
+            MutCache mc("mutable_test", 2, 2s, clock, journal);
+
+            // A. Insert on miss: fetch_and_modify creates entry and mutates it
+            mc.fetch_and_modify(5, [](MutableValue& v) {
+                v.counter = 42;
+                v.name = "initial";
+            });
+
+            BEAST_EXPECT(mc.getCacheSize() == 1);
+            BEAST_EXPECT(mc.getTrackSize() == 1);
+
+            // Verify the mutation persisted
+            auto p1 = mc.fetch(5);
+            BEAST_EXPECT(p1 != nullptr);
+            BEAST_EXPECT(p1->counter == 42);
+            BEAST_EXPECT(p1->name == "initial");
+
+            // B. Modify existing object on hit
+            // Keep strong pointer to verify in-place modification
+            auto p2 = mc.fetch(5);
+            BEAST_EXPECT(p2 != nullptr);
+            BEAST_EXPECT(p1.get() == p2.get());  // Same object
+
+            // Modify through fetch_and_modify
+            mc.fetch_and_modify(5, [](MutableValue& v) {
+                v.counter += 10;
+                v.name = "modified";
+            });
+
+            // Verify no new entry was created
+            BEAST_EXPECT(mc.getCacheSize() == 1);
+            BEAST_EXPECT(mc.getTrackSize() == 1);
+
+            // Verify the same object was mutated (strong pointer sees change)
+            BEAST_EXPECT(p1->counter == 52);
+            BEAST_EXPECT(p1->name == "modified");
+            BEAST_EXPECT(p2->counter == 52);  // Original pointer sees mutation
+
+            // Verify via fresh fetch
+            auto p3 = mc.fetch(5);
+            BEAST_EXPECT(p3 != nullptr);
+            BEAST_EXPECT(p3.get() == p1.get());  // Same object identity
+            BEAST_EXPECT(p3->counter == 52);
+        }
     }
 };
 
diff --git a/src/tests/libxrpl/ledger/main.cpp b/src/tests/libxrpl/ledger/main.cpp
deleted file mode 100644
index 5142bbe08a..0000000000
--- a/src/tests/libxrpl/ledger/main.cpp
+++ /dev/null
@@ -1,8 +0,0 @@
-#include <gtest/gtest.h>
-
-int
-main(int argc, char** argv)
-{
-    ::testing::InitGoogleTest(&argc, argv);
-    return RUN_ALL_TESTS();
-}