Add CMake script to generate ctest definitions from Catch tests (#879)

Added cmake script to parse the source files containing Catch's test and generate ctest definitions.

It generates one ctest test per `TEST_CASE` and labels them, using the `TEST_CASE`'s tags.

Closes #719.
diff --git a/contrib/ParseAndAddCatchTests.cmake b/contrib/ParseAndAddCatchTests.cmake
new file mode 100644
index 0000000..81636e3
--- /dev/null
+++ b/contrib/ParseAndAddCatchTests.cmake
@@ -0,0 +1,114 @@
+#==================================================================================================#
+#  supported macros                                                                                #
+#    - TEST_CASE,                                                                                  #
+#    - SCENARIO,                                                                                   #
+#    - TEST_CASE_METHOD,                                                                           #
+#    - CATCH_TEST_CASE,                                                                            #
+#    - CATCH_SCENARIO,                                                                             #
+#    - CATCH_TEST_CASE_METHOD.                                                                     #
+#                                                                                                  #
+#  Usage                                                                                           #
+# 1. make sure this module is in the path or add this otherwise:                                   #
+#    set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake.modules/")              #
+# 2. make sure that you've enabled testing option for the project by the call:                     #
+#    enable_testing()                                                                              #
+# 3. add the lines to the script for testing target (sample CMakeLists.txt):                       #
+#        project(testing_target)                                                                   #
+#        set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake.modules/")          #
+#        enable_testing()                                                                          #
+#                                                                                                  #
+#        find_path(CATCH_INCLUDE_DIR "catch.hpp")                                                  #
+#        include_directories(${INCLUDE_DIRECTORIES} ${CATCH_INCLUDE_DIR})                          #
+#                                                                                                  #
+#        file(GLOB SOURCE_FILES "*.cpp")                                                           #
+#        add_executable(${PROJECT_NAME} ${SOURCE_FILES})                                           #
+#                                                                                                  #
+#        include(ParseAndAddCatchTests)                                                            #
+#        ParseAndAddCatchTests(${PROJECT_NAME})                                                    #
+#==================================================================================================#
+
+cmake_minimum_required(VERSION 2.8.8)
+
+# This removes the contents between
+#  - block comments (i.e. /* ... */) 
+#  - full line comments (i.e. // ... ) 
+# contents have been read into '${CppCode}'.
+# !keep partial line comments
+function(RemoveComments CppCode)
+  string(ASCII 2 CMakeBeginBlockComment)
+  string(ASCII 3 CMakeEndBlockComment)
+  string(REGEX REPLACE "/\\*" "${CMakeBeginBlockComment}" ${CppCode} "${${CppCode}}")
+  string(REGEX REPLACE "\\*/" "${CMakeEndBlockComment}" ${CppCode} "${${CppCode}}")
+  string(REGEX REPLACE "${CMakeBeginBlockComment}[^${CMakeEndBlockComment}]*${CMakeEndBlockComment}" "" ${CppCode} "${${CppCode}}")
+  string(REGEX REPLACE "\n[ \t]*//+[^\n]+" "\n" ${CppCode} "${${CppCode}}")
+
+  set(${CppCode} "${${CppCode}}" PARENT_SCOPE)
+endfunction()
+
+# Worker function
+function(ParseFile SourceFile TestTarget)
+    if(NOT EXISTS ${SourceFile})
+        return()
+    endif()
+    file(STRINGS ${SourceFile} Contents NEWLINE_CONSUME)
+
+    # Remove block and fullline comments
+    RemoveComments(Contents)
+
+    # Find definition of test names
+    string(REGEX MATCHALL "[ \t]*(CATCH_)?(TEST_CASE_METHOD|SCENARIO|TEST_CASE)[ \t]*\\([^\)]+\\)+[ \t]*{+[ \t]*(//[^\n]*[Tt][Ii][Mm][Ee][Oo][Uu][Tt][ \t]*[0-9]+)*" Tests "${Contents}")
+
+    foreach(TestName ${Tests})
+        # Strip newlines
+        string(REGEX REPLACE "\\\\\n|\n" "" TestName "${TestName}")
+
+        # Get test type and fixture if applicable
+        string(REGEX MATCH "(CATCH_)?(TEST_CASE_METHOD|SCENARIO|TEST_CASE)[ \t]*\\([^,^\"]*" TestTypeAndFixture "${TestName}")
+        string(REGEX MATCH "(CATCH_)?(TEST_CASE_METHOD|SCENARIO|TEST_CASE)" TestType "${TestTypeAndFixture}")
+        string(REPLACE "${TestType}(" "" TestFixture "${TestTypeAndFixture}")
+
+        # Get string parts of test definition
+        string(REGEX MATCHALL "\"+([^\\^\"]|\\\\\")+\"+" TestStrings "${TestName}")
+
+        # Strip wrapping quotation marks
+        string(REGEX REPLACE "^\"(.*)\"$" "\\1" TestStrings "${TestStrings}")
+        string(REPLACE "\";\"" ";" TestStrings "${TestStrings}")
+
+        # Validate that a test name and tags have been provided
+        list(LENGTH TestStrings TestStringsLength)
+        if(TestStringsLength GREATER 2 OR TestStringsLength LESS 1)
+            message(FATAL_ERROR "You must provide a valid test name and tags for all tests in ${SourceFile}")
+        endif()
+
+        # Assign name and tags
+        list(GET TestStrings 0 Name)
+        if("${TestType}" STREQUAL "SCENARIO")
+            set(Name "Scenario: ${Name}")
+        endif()
+        if(TestFixture)
+            set(CTestName "${TestFixture}:${Name}")
+        else()
+            set(CTestName "${Name}")
+        endif()
+        if(TestStringsLength EQUAL 2)
+            list(GET TestStrings 1 Tags)
+            string(TOLOWER "${Tags}" Tags)
+            string(REPLACE "]" ";" Tags "${Tags}")
+            string(REPLACE "[" "" Tags "${Tags}")
+        endif()
+
+        # Add the test and set its properties
+        add_test(NAME "\"${CTestName}\"" COMMAND ${TestTarget} ${Name} ${AdditionalCatchParameters})
+        set_tests_properties("\"${CTestName}\"" PROPERTIES FAIL_REGULAR_EXPRESSION "No tests ran"
+                                                LABELS "${Tags}")
+
+    endforeach()
+endfunction()
+
+# entry point
+function(ParseAndAddCatchTests TestTarget)
+    get_target_property(SourceFiles ${TestTarget} SOURCES)
+    foreach(SourceFile ${SourceFiles})
+        ParseFile(${SourceFile} ${TestTarget})
+    endforeach()
+endfunction()
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