Help:add_test: emphasize important points

* enable_testing must be called to enable testing
* can only set properties on tests created in same directory
* WILL_FAIL still fails on segfault and similar
* compact wording

Help/command/add_test.rst

@@ -12,13 +12,24 @@ Add a test to the project to be run by :manual:`ctest(1)`.
 
 Adds a test called ``<name>``.  The test name may contain arbitrary
 characters, expressed as a :ref:`Quoted Argument` or :ref:`Bracket Argument`
-if necessary.  See policy :policy:`CMP0110`.  The options are:
+if necessary.  See policy :policy:`CMP0110`.
+
+CMake only generates tests if the :command:`enable_testing` command has been
+invoked.  The :module:`CTest` module invokes ``enable_testing`` automatically
+unless ``BUILD_TESTING`` is set to ``OFF``.
+
+Tests added with the ``add_test(NAME)`` signature support using
+:manual:`generator expressions <cmake-generator-expressions(7)>`
+in test properties set by :command:`set_property(TEST)` or
+:command:`set_tests_properties`. Test properties may only be set in the
+directory the test is created in.
+
+``add_test`` options are:
 
 ``COMMAND``
-  Specify the test command-line.  If ``<command>`` specifies an
-  executable target (created by :command:`add_executable`) it will
-  automatically be replaced by the location of the executable created
-  at build time.
+  Specify the test command-line.  If ``<command>`` specifies an executable
+  target created by :command:`add_executable`, it will automatically be
+  replaced by the location of the executable created at build time.
 
   The command may be specified using
   :manual:`generator expressions <cmake-generator-expressions(7)>`.
@@ -27,38 +38,29 @@ if necessary.  See policy :policy:`CMP0110`.  The options are:
   Restrict execution of the test only to the named configurations.
 
 ``WORKING_DIRECTORY``
-  Set the :prop_test:`WORKING_DIRECTORY` test property to
-  specify the working directory in which to execute the test.
-  If not specified the test will be run with the current working
-  directory set to the build directory corresponding to the
-  current source directory.
-
-  The working directory may be specified using
-  :manual:`generator expressions <cmake-generator-expressions(7)>`.
+  Set the test property :prop_test:`WORKING_DIRECTORY` in which to execute the
+  test. If not specified, the test will be run in
+  :variable:`CMAKE_CURRENT_BINARY_DIR`. The working directory may be specified
+  using :manual:`generator expressions <cmake-generator-expressions(7)>`.
 
 ``COMMAND_EXPAND_LISTS``
   .. versionadded:: 3.16
 
-  Lists in ``COMMAND`` arguments will be expanded, including those
-  created with
+  Lists in ``COMMAND`` arguments will be expanded, including those created with
   :manual:`generator expressions <cmake-generator-expressions(7)>`.
 
-The given test command is expected to exit with code ``0`` to pass and
-non-zero to fail, or vice-versa if the :prop_test:`WILL_FAIL` test
-property is set.  Any output written to stdout or stderr will be
-captured by :manual:`ctest(1)` but does not affect the pass/fail status
-unless the :prop_test:`PASS_REGULAR_EXPRESSION`,
-:prop_test:`FAIL_REGULAR_EXPRESSION` or
-:prop_test:`SKIP_REGULAR_EXPRESSION` test property is used.
+If the test command exits with code ``0`` the test passes. Non-zero exit code
+is a "failed" test. The test property :prop_test:`WILL_FAIL` inverts this
+logic. Note that system-level test failures such as segmentation faults or
+heap errors will still fail the test even if ``WILL_FALL`` is true. Output
+written to stdout or stderr is captured by :manual:`ctest(1)` and only
+affects the pass/fail status via the :prop_test:`PASS_REGULAR_EXPRESSION`,
+:prop_test:`FAIL_REGULAR_EXPRESSION`, or :prop_test:`SKIP_REGULAR_EXPRESSION`
+test properties.
 
 .. versionadded:: 3.16
   Added :prop_test:`SKIP_REGULAR_EXPRESSION` property.
 
-Tests added with the ``add_test(NAME)`` signature support using
-:manual:`generator expressions <cmake-generator-expressions(7)>`
-in test properties set by :command:`set_property(TEST)` or
-:command:`set_tests_properties`.
-
 Example usage:
 
 .. code-block:: cmake
@@ -71,16 +73,9 @@ This creates a test ``mytest`` whose command runs a ``testDriver`` tool
 passing the configuration name and the full path to the executable
 file produced by target ``myexe``.
 
-.. note::
-
-  CMake will generate tests only if the :command:`enable_testing`
-  command has been invoked.  The :module:`CTest` module invokes the
-  command automatically unless the ``BUILD_TESTING`` option is turned
-  ``OFF``.
-
 ---------------------------------------------------------------------
 
-This command also supports a simpler, but less flexible, signature:
+The command syntax above is recommended over the older, less flexible form:
 
 .. code-block:: cmake
 

Help/command/set_property.rst

@@ -82,8 +82,8 @@ It must be one of the following:
   to the installation prefix.
 
 ``TEST``
-  Scope may name zero or more existing tests.
-  See also the :command:`set_tests_properties` command.
+  Scope is limited to the directory the command is called in. It may name zero
+  or more existing tests. See also command :command:`set_tests_properties`.
 
   Test property values may be specified using
   :manual:`generator expressions <cmake-generator-expressions(7)>`

Help/prop_test/WILL_FAIL.rst

@@ -3,5 +3,6 @@ WILL_FAIL
 
 If set to true, this will invert the pass/fail flag of the test.
 
-This property can be used for tests that are expected to fail and
-return a non zero return code.
+This property can be used for tests that are expected to fail and return a
+non-zero return code. Note that system-level test failures such as segmentation
+faults or heap errors will still fail the test even if ``WILL_FALL`` is true.