[TEST] Add CLI --timing-output test.

test/cli/CMakeLists.txt

@@ -14,3 +14,6 @@ target_use_datasources (cli_chopper_pipeline_test FILES seq1.fa)
 target_use_datasources (cli_chopper_pipeline_test FILES small.fa)
 target_use_datasources (cli_chopper_pipeline_test FILES small2.fa)
 target_use_datasources (cli_chopper_pipeline_test FILES small.split)
+
+add_cli_test (cli_timing_output_test.cpp)
+target_use_datasources (cli_chopper_pipeline_test FILES small.fa)

test/cli/cli_timing_output_test.cpp

@@ -0,0 +1,45 @@
+// ---------------------------------------------------------------------------------------------------
+// Copyright (c) 2006-2023, Knut Reinert & Freie Universität Berlin
+// Copyright (c) 2016-2023, Knut Reinert & MPI für molekulare Genetik
+// This file may be used, modified and/or redistributed under the terms of the 3-clause BSD-License
+// shipped with this file and also available at: https://github.com/seqan/chopper/blob/main/LICENSE.md
+// ---------------------------------------------------------------------------------------------------
+
+#include <gtest/gtest.h>
+
+#include <filesystem>
+#include <fstream>
+#include <string> // strings
+
+#include <seqan3/test/tmp_directory.hpp>
+
+#include "cli_test.hpp"
+
+TEST_F(cli_test, timing_output)
+{
+    std::string const seq_filename = data("small.fa");
+    seqan3::test::tmp_directory tmp_dir{};
+    std::filesystem::path const input_filename{tmp_dir.path() / "data.tsv"};
+    std::filesystem::path const layout_filename{tmp_dir.path() / "output.layout"};
+    std::filesystem::path const timing_filename{tmp_dir.path() / "output.timings"};
+
+    {
+        std::ofstream fout{input_filename};
+        fout << seq_filename << '\n' << seq_filename << '\n' << seq_filename << '\n';
+    }
+
+    cli_test_result result = execute_app("chopper",
+                                         "--input",
+                                         input_filename.c_str(),
+                                         "--output",
+                                         layout_filename.c_str(),
+                                         "--timing-output",
+                                         timing_filename.c_str());
+
+    EXPECT_EQ(result.exit_code, 0);
+    EXPECT_EQ(result.out, std::string{});
+    EXPECT_EQ(result.err, std::string{});
+
+    EXPECT_TRUE(std::filesystem::exists(timing_filename)); // file should have been written
+    // not not check output since it is not relevant how exectly the timings look like
+}