Tests/GTestWrapper: file header comments

Tests/GTestWrapper/TestAll.cpp

+//  ************************************************************************************************
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      Tests/GTestWrapper/TestAll.cpp
+//! @brief     Implements main, for use in various test directories.
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2018
+//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
+//
+//  ************************************************************************************************
+
 #include "Tests/GTestWrapper/google_test.h"
 
+//! Main program for use in various test directories.
+//!
+//! We need this function instead of gtest_main [1] because we want to use our
+//! wrapper google_test.h instead of gtest.h.
+//!
+//! We compile this function separately in each test directory, and link it with
+//! source files that contain TEST_F macros.
+//!
+//! [1] https://github.com/google/googletest/blob/master/googletest/docs/primer.md
+//!     #writing-the-main-function
+
 int main(int argc, char** argv) {
     ::testing::InitGoogleTest(&argc, argv);
 

Tests/GTestWrapper/google_test.h

+//  ************************************************************************************************
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      Tests/GTestWrapper/google_test.h
+//! @brief     Wraps gtest.h, and provides tests for complex number.
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2018
+//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
+//
+//  ************************************************************************************************
+
 #ifndef BORNAGAIN_TESTS_GTESTWRAPPER_GOOGLE_TEST_H
 #define BORNAGAIN_TESTS_GTESTWRAPPER_GOOGLE_TEST_H