Method processWithFuzzing

programs/client/Client.cpp:1345–1614

Returns false when server is not available.

    /// Returns false when server is not available.
    bool processWithFuzzing(const String & text)
    {
        ASTPtr orig_ast;

        try
        {
            const char * begin = text.data();
            orig_ast = parseQuery(begin, begin + text.size(), true);
        }
        catch (const Exception & e)
        {
            if (e.code() != ErrorCodes::SYNTAX_ERROR && e.code() != ErrorCodes::TOO_DEEP_RECURSION)
                throw;
        }

        if (!orig_ast)
        {
            // Can't continue after a parsing error
            return true;
        }

        // Don't repeat inserts, the tables grow too big. Also don't repeat
        // creates because first we run the unmodified query, it will succeed,
        // and the subsequent queries will fail. When we run out of fuzzer
        // errors, it may be interesting to add fuzzing of create queries that
        // wraps columns into LowCardinality or Nullable. Also there are other
        // kinds of create queries such as CREATE DICTIONARY, we could fuzz
        // them as well. Also there is no point fuzzing DROP queries.
        size_t this_query_runs = query_fuzzer_runs;
        if (orig_ast->as<ASTInsertQuery>() || orig_ast->as<ASTCreateQuery>() || orig_ast->as<ASTDropQuery>())
        {
            this_query_runs = 1;
        }

        ASTPtr fuzz_base = orig_ast;
        for (size_t fuzz_step = 0; fuzz_step < this_query_runs; ++fuzz_step)
        {
            fmt::print(stderr, "Fuzzing step {} out of {}\n", fuzz_step, this_query_runs);

            ASTPtr ast_to_process;
            try
            {
                WriteBufferFromOwnString dump_before_fuzz;
                fuzz_base->dumpTree(dump_before_fuzz);
                auto base_before_fuzz = fuzz_base->formatForErrorMessage();

                ast_to_process = fuzz_base->clone();

                WriteBufferFromOwnString dump_of_cloned_ast;
                ast_to_process->dumpTree(dump_of_cloned_ast);

                // Run the original query as well.
                if (fuzz_step > 0)
                {
                    fuzzer.fuzzMain(ast_to_process);
                }

                auto base_after_fuzz = fuzz_base->formatForErrorMessage();