From cc7ff4122d75b6cd23270039e5b751fbe09331a2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luis=20D=C3=ADaz=20M=C3=A1s?= <piponazo@gmail.com>
Date: Thu, 23 Nov 2017 22:44:09 +0100
Subject: [PATCH] Export all symbols when running unit tests. Add dummy test
 for private code.

I tried to use directly the private OBJECT library (exiv2lib_int) in the unit_tests targets, but the private objects have dependencies on the public symbols (circular dependency)
and therefore it is impossible to test the private code with that approach with the current design of the library.

Starting from CMake 3.3 we can use the variable CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS to export all the symbols of a shared library:
https://blog.kitware.com/create-dlls-on-windows-without-declspec-using-new-cmake-export-all-feature/

Even having the opportunity to use this variable (that will be only used when EXIV2_BUILD_UNIT_TESTS is enabled) the previous commits are still valid.
It is interesting to clearly differentiate between the public and private code of the library. Enforcing this, make us think twice before putting code in the public
part of the library.
---
 CMakeLists.txt                |  4 ++++
 unitTests/CMakeLists.txt      |  6 ++++--
 unitTests/test_tiffheader.cpp | 22 ++++++++++++++++++++++
 3 files changed, 30 insertions(+), 2 deletions(-)
 create mode 100644 unitTests/test_tiffheader.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 87a167ce..96426850 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -74,6 +74,10 @@ if( EXIV2_ENABLE_COMMERCIAL )
     set (EXIV2_ENABLE_NLS OFF)
 endif()
 
+if( EXIV2_BUILD_UNIT_TESTS )
+    set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON) # Requires CMake 3.3.3
+endif()
+
 include(config/findDependencies.cmake)
 include(config/compilerFlags.cmake)
 include( config/generateConfigFile.cmake )
diff --git a/unitTests/CMakeLists.txt b/unitTests/CMakeLists.txt
index 2f141d2e..735543ed 100644
--- a/unitTests/CMakeLists.txt
+++ b/unitTests/CMakeLists.txt
@@ -1,10 +1,11 @@
 add_executable(unit_tests mainTestRunner.cpp
-    test_types.cpp
     gtestwrapper.h
+    test_types.cpp
+    test_tiffheader.cpp
 )
 
 #TODO Use GTest::GTest once we upgrade the minimum CMake version required
-target_link_libraries(unit_tests 
+target_link_libraries(unit_tests
     PRIVATE
         exiv2lib
         ${GTEST_BOTH_LIBRARIES}
@@ -13,6 +14,7 @@ target_link_libraries(unit_tests
 target_include_directories(unit_tests
     PRIVATE
         ${GTEST_INCLUDE_DIRS}
+        ${CMAKE_SOURCE_DIR}/src
 )
 
 target_compile_definitions(unit_tests
diff --git a/unitTests/test_tiffheader.cpp b/unitTests/test_tiffheader.cpp
new file mode 100644
index 00000000..8afa721e
--- /dev/null
+++ b/unitTests/test_tiffheader.cpp
@@ -0,0 +1,22 @@
+#include <tiffimage_int.hpp>
+
+#include "gtestwrapper.h"
+#include <sstream>
+
+using namespace Exiv2;
+
+static const byte tiffLittleEndian[] = {0x49, 0x49, 0x2a, 0x00, 0x10, 0x00, 0x00, 0x00};
+
+class ATiffHeader: public ::testing::Test
+{
+public:
+    Internal::TiffHeader header;
+};
+
+TEST_F(ATiffHeader, hasExpectedValuesAfterCreation)
+{
+    ASSERT_EQ(8u, header.size());
+    ASSERT_EQ(42, header.tag());
+    ASSERT_EQ(8u, header.offset());
+    ASSERT_EQ(littleEndian, header.byteOrder());
+}