move-only: unittest: add test/util/chainstate.h

and move `CreateAndActivateUTXOSnapshot()` into it for reuse
in future test modules.

src/Makefile.test_util.include

@@ -9,6 +9,7 @@ EXTRA_LIBRARIES += \
 
 TEST_UTIL_H = \
     test/util/blockfilter.h \
+    test/util/chainstate.h \
     test/util/logging.h \
     test/util/mining.h \
     test/util/net.h \

src/test/util/chainstate.h

@@ -0,0 +1,54 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+//
+#ifndef BITCOIN_TEST_UTIL_CHAINSTATE_H
+#define BITCOIN_TEST_UTIL_CHAINSTATE_H
+
+#include <clientversion.h>
+#include <fs.h>
+#include <node/context.h>
+#include <node/utxo_snapshot.h>
+#include <rpc/blockchain.h>
+#include <validation.h>
+
+#include <univalue.h>
+
+#include <boost/test/unit_test.hpp>
+
+auto NoMalleation = [](CAutoFile& file, SnapshotMetadata& meta){};
+
+/**
+ * Create and activate a UTXO snapshot, optionally providing a function to
+ * malleate the snapshot.
+ */
+template<typename F = decltype(NoMalleation)>
+static bool
+CreateAndActivateUTXOSnapshot(NodeContext& node, const fs::path root, F malleation = NoMalleation)
+{
+    // Write out a snapshot to the test's tempdir.
+    //
+    int height;
+    WITH_LOCK(::cs_main, height = node.chainman->ActiveHeight());
+    fs::path snapshot_path = root / tfm::format("test_snapshot.%d.dat", height);
+    FILE* outfile{fsbridge::fopen(snapshot_path, "wb")};
+    CAutoFile auto_outfile{outfile, SER_DISK, CLIENT_VERSION};
+
+    UniValue result = CreateUTXOSnapshot(node, node.chainman->ActiveChainstate(), auto_outfile);
+    BOOST_TEST_MESSAGE(
+        "Wrote UTXO snapshot to " << snapshot_path.make_preferred().string() << ": " << result.write());
+
+    // Read the written snapshot in and then activate it.
+    //
+    FILE* infile{fsbridge::fopen(snapshot_path, "rb")};
+    CAutoFile auto_infile{infile, SER_DISK, CLIENT_VERSION};
+    SnapshotMetadata metadata;
+    auto_infile >> metadata;
+
+    malleation(auto_infile, metadata);
+
+    return node.chainman->ActivateSnapshot(auto_infile, metadata, /*in_memory*/ true);
+}
+
+
+#endif // BITCOIN_TEST_UTIL_CHAINSTATE_H

src/test/validation_chainstatemanager_tests.cpp

@@ -9,12 +9,12 @@
 #include <rpc/blockchain.h>
 #include <sync.h>
 #include <test/util/setup_common.h>
+#include <test/util/chainstate.h>
 #include <uint256.h>
 #include <validation.h>
 #include <validationinterface.h>
 
 #include <tinyformat.h>
-#include <univalue.h>
 
 #include <vector>
 
@@ -154,36 +154,6 @@ BOOST_AUTO_TEST_CASE(chainstatemanager_rebalance_caches)
     BOOST_CHECK_CLOSE(c2.m_coinsdb_cache_size_bytes, max_cache * 0.95, 1);
 }
 
-auto NoMalleation = [](CAutoFile& file, SnapshotMetadata& meta){};
-
-template<typename F = decltype(NoMalleation)>
-static bool
-CreateAndActivateUTXOSnapshot(NodeContext& node, const fs::path root, F malleation = NoMalleation)
-{
-    // Write out a snapshot to the test's tempdir.
-    //
-    int height;
-    WITH_LOCK(::cs_main, height = node.chainman->ActiveHeight());
-    fs::path snapshot_path = root / tfm::format("test_snapshot.%d.dat", height);
-    FILE* outfile{fsbridge::fopen(snapshot_path, "wb")};
-    CAutoFile auto_outfile{outfile, SER_DISK, CLIENT_VERSION};
-
-    UniValue result = CreateUTXOSnapshot(node, node.chainman->ActiveChainstate(), auto_outfile);
-    BOOST_TEST_MESSAGE(
-        "Wrote UTXO snapshot to " << snapshot_path.make_preferred().string() << ": " << result.write());
-
-    // Read the written snapshot in and then activate it.
-    //
-    FILE* infile{fsbridge::fopen(snapshot_path, "rb")};
-    CAutoFile auto_infile{infile, SER_DISK, CLIENT_VERSION};
-    SnapshotMetadata metadata;
-    auto_infile >> metadata;
-
-    malleation(auto_infile, metadata);
-
-    return node.chainman->ActivateSnapshot(auto_infile, metadata, /*in_memory*/ true);
-}
-
 //! Test basic snapshot activation.
 BOOST_FIXTURE_TEST_CASE(chainstatemanager_activate_snapshot, TestChain100Setup)
 {