test: Add ASSERT_DEBUG_LOG to unit test framework

src/test/lib/logging.cpp

@@ -0,0 +1,32 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <test/lib/logging.h>
+
+#include <logging.h>
+#include <noui.h>
+#include <tinyformat.h>
+#include <util/memory.h>
+
+#include <stdexcept>
+
+DebugLogHelper::DebugLogHelper(std::string message)
+    : m_message{std::move(message)}
+{
+    m_print_connection = LogInstance().PushBackCallback(
+        [this](const std::string& s) {
+            if (m_found) return;
+            m_found = s.find(m_message) != std::string::npos;
+        });
+    noui_test_redirect();
+}
+
+void DebugLogHelper::check_found()
+{
+    noui_reconnect();
+    LogInstance().DeleteCallback(m_print_connection);
+    if (!m_found) {
+        throw std::runtime_error(strprintf("'%s' not found in debug log\n", m_message));
+    }
+}

src/test/lib/logging.h

@@ -0,0 +1,29 @@
+// Copyright (c) 2019 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_LIB_LOGGING_H
+#define BITCOIN_TEST_LIB_LOGGING_H
+
+#include <util/macros.h>
+
+#include <functional>
+#include <list>
+#include <string>
+
+class DebugLogHelper
+{
+    const std::string m_message;
+    bool m_found{false};
+    std::list<std::function<void(const std::string&)>>::iterator m_print_connection;
+
+    void check_found();
+
+public:
+    DebugLogHelper(std::string message);
+    ~DebugLogHelper() { check_found(); }
+};
+
+#define ASSERT_DEBUG_LOG(message) DebugLogHelper PASTE2(debugloghelper, __COUNTER__)(message)
+
+#endif // BITCOIN_TEST_LIB_LOGGING_H

src/test/timedata_tests.cpp

@@ -5,6 +5,7 @@
 
 #include <netaddress.h>
 #include <noui.h>
+#include <test/lib/logging.h>
 #include <test/setup_common.h>
 #include <timedata.h>
 #include <warnings.h>
@@ -59,9 +60,10 @@ BOOST_AUTO_TEST_CASE(addtimedata)
     MultiAddTimeData(3, DEFAULT_MAX_TIME_ADJUSTMENT + 1);
     // Filter size is 1 + 3 = 4: It is always initialized with a single element (offset 0)
 
-    noui_suppress();
-    MultiAddTimeData(1, DEFAULT_MAX_TIME_ADJUSTMENT + 1); //filter size 5
-    noui_reconnect();
+    {
+        ASSERT_DEBUG_LOG("Please check that your computer's date and time are correct!");
+        MultiAddTimeData(1, DEFAULT_MAX_TIME_ADJUSTMENT + 1); //filter size 5
+    }
 
     BOOST_CHECK(GetWarnings("gui").find("clock is wrong") != std::string::npos);