Introduce ModSecurityTestContext to encapsulate setup of objects required to execute transactions

- Simplifies memory management on error conditions
- Context will be used in unit tests too, in order to provide
  Transaction related instances.

test/common/custom_debug_log.h

@@ -0,0 +1,45 @@
+/*
+ * ModSecurity, http://www.modsecurity.org/
+ * Copyright (c) 2015 - 2021 Trustwave Holdings, Inc. (http://www.trustwave.com/)
+ *
+ * You may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * If any of the files related to licensing are missing or if you have any
+ * other questions related to licensing please contact Trustwave Holdings, Inc.
+ * directly using the email address security@modsecurity.org.
+ *
+ */
+
+#include <sstream>
+#include <string>
+
+#include "modsecurity/debug_log.h"
+
+#ifndef TEST_REGRESSION_CUSTOM_DEBUG_LOG_H_
+#define TEST_REGRESSION_CUSTOM_DEBUG_LOG_H_
+
+namespace modsecurity_test {
+
+class CustomDebugLog : public modsecurity::debug_log::DebugLog {
+ public:
+    CustomDebugLog *new_instance();
+    ~CustomDebugLog();
+
+    void write(int level, const std::string& message) override;
+    void write(int level, const std::string &id,
+        const std::string &uri, const std::string &msg) override;
+    bool const contains(const std::string& pattern) const;
+    std::string const log_messages() const;
+    std::string error_log_messages();
+    int getDebugLogLevel() override;
+
+ private:
+    std::stringstream m_log;
+};
+
+}  // namespace modsecurity_test
+
+#endif  // TEST_REGRESSION_CUSTOM_DEBUG_LOG_H_