set: Add unit tests for set/unset PARENT_SCOPE

Create a RunCMake.set test to cover set() command cases, starting with
PARENT_SCOPE.

Tests/RunCMake/CMakeLists.txt

@@ -107,6 +107,7 @@ add_RunCMake_test(list)
 add_RunCMake_test(message)
 add_RunCMake_test(string)
 add_RunCMake_test(try_compile)
+add_RunCMake_test(set)
 add_RunCMake_test(variable_watch)
 add_RunCMake_test(CMP0004)
 add_RunCMake_test(TargetPolicies)

Tests/RunCMake/set/CMakeLists.txt

@@ -0,0 +1,3 @@
+cmake_minimum_required(VERSION 2.8.12)
+project(${RunCMake_TEST} NONE)
+include(${RunCMake_TEST}.cmake)

Tests/RunCMake/set/PARENT_SCOPE-result.txt

@@ -0,0 +1 @@
+0

Tests/RunCMake/set/PARENT_SCOPE.cmake

@@ -0,0 +1,33 @@
+set(FOO )
+set(BAR "bar")
+set(BAZ "baz")
+set(BOO "boo")
+
+function(_parent_scope)
+    set(FOO "foo" PARENT_SCOPE)
+    set(BAR "" PARENT_SCOPE)
+    set(BAZ PARENT_SCOPE)
+    unset(BOO PARENT_SCOPE)
+endfunction()
+
+_parent_scope()
+
+if(NOT DEFINED FOO)
+  message(FATAL_ERROR "FOO not defined")
+elseif(NOT "${FOO}" STREQUAL "foo")
+  message(FATAL_ERROR "FOO should be \"foo\", not \"${FOO}\"")
+endif()
+
+if(NOT DEFINED BAR)
+  message(FATAL_ERROR "BAR not defined")
+elseif(NOT "${BAR}" STREQUAL "")
+  message(FATAL_ERROR "BAR should be an empty string, not \"${BAR}\"")
+endif()
+
+if(DEFINED BAZ)
+  message(FATAL_ERROR "BAZ defined")
+endif()
+
+if(DEFINED BOO)
+  message(FATAL_ERROR "BOO defined")
+endif()

Tests/RunCMake/set/RunCMakeTest.cmake

@@ -0,0 +1,3 @@
+include(RunCMake)
+
+run_cmake(PARENT_SCOPE)