Use CMake's CTest which includes BUILD_TESTING option

BUILD_TESTING is default enabled, which is a good default anyway.
Move the CppUnit check to the root CMakeLists.txt, simpler and clearer.
BUILD_TESTS is obsolete.

The need for BUILD_SHARED_LIBS=OFF for testing is not clear, it works on Linux.
But I kept it in the instructions for now.

Signed-off-by: Andreas Sturmlechner <asturm@gentoo.org>

CMakeLists.txt

@@ -4,6 +4,8 @@ project(taglib)
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")
 
+include(CTest)
+
 if(DEFINED ENABLE_STATIC)
   message(FATAL_ERROR "This option is no longer available, use BUILD_SHARED_LIBS instead")
 endif()
@@ -32,7 +34,6 @@ if(ENABLE_CCACHE)
 endif()
 
 option(VISIBILITY_HIDDEN "Build with -fvisibility=hidden" OFF)
-option(BUILD_TESTS "Build the test suite" OFF)
 option(BUILD_EXAMPLES "Build the examples" OFF)
 option(BUILD_BINDINGS "Build the bindings" ON)
 
@@ -147,9 +148,13 @@ if(BUILD_BINDINGS)
   add_subdirectory(bindings)
 endif()
 
-if(BUILD_TESTS AND NOT BUILD_SHARED_LIBS)
-  enable_testing()
-  add_subdirectory(tests)
+if(BUILD_TESTING)
+  find_package(CppUnit)
+  if(CppUnit_FOUND)
+    add_subdirectory(tests)
+  else()
+    message(WARNING "BUILD_TESTING requested, but CppUnit not found, skipping tests.")
+  endif()
 endif()
 
 if(BUILD_EXAMPLES)

ConfigureChecks.cmake

@@ -187,16 +187,6 @@ if(NOT ZLIB_SOURCE)
   endif()
 endif()
 
-# Determine whether CppUnit is installed.
-
-if(BUILD_TESTS AND NOT BUILD_SHARED_LIBS)
-  find_package(CppUnit)
-  if(NOT CppUnit_FOUND)
-    message(STATUS "CppUnit not found, disabling tests.")
-    set(BUILD_TESTS OFF)
-  endif()
-endif()
-
 # Detect WinRT mode
 if(CMAKE_SYSTEM_NAME STREQUAL "WindowsStore")
 	set(PLATFORM WINRT 1)

INSTALL.md

@@ -167,7 +167,7 @@ Unit Tests
 
 If you want to run the test suite to make sure TagLib works properly on your
 system, you need to have cppunit installed. To build the tests, include
-the option `-DBUILD_TESTS=ON -DBUILD_SHARED_LIBS=OFF` when running cmake.
+the option `-DBUILD_TESTING=ON` when running cmake.
 
 The test suite has a custom target in the build system, so you can run
 the tests using make:
@@ -183,7 +183,7 @@ Windows MinGW:
   - `mingw32-make; mingw32-make install DESTDIR=/path/to/install/dir`
 * Build TagLib with testing enabled:
   - ```
-    cmake -G "MinGW Makefiles" -DBUILD_TESTS=ON -DBUILD_EXAMPLES=ON -DBUILD_SHARED_LIBS=OFF \
+    cmake -G "MinGW Makefiles" -DBUILD_TESTING=ON -DBUILD_EXAMPLES=ON -DBUILD_SHARED_LIBS=OFF \
     -DCPPUNIT_INCLUDE_DIR=/path/to/cppunit/include \
     -DCPPUNIT_LIBRARIES=/path/to/cppunit/lib/libcppunit.a \
     -DCPPUNIT_INSTALLED_VERSION=1.15.1
@@ -200,7 +200,7 @@ Windows MSVS:
   - It may fail, but the needed libraries should be available in src\cppunit\DebugDll.
 * Build TagLib with testing enabled:
   - ```
-    cmake -G "Visual Studio 16 2019" -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTS=ON -DBUILD_EXAMPLES=ON
+    cmake -G "Visual Studio 16 2019" -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTING=ON -DBUILD_EXAMPLES=ON
     -DBUILD_SHARED_LIBS=OFF -DENABLE_STATIC_RUNTIME=ON
     -DCPPUNIT_INCLUDE_DIR=\path\to\cppunit\include
     -DCPPUNIT_LIBRARIES=\path\to\cppunit\DebugDll\cppunitd_dll.lib