docs: Update MathComponent to Reference TestMain (#1030)

* docs: MathComponent References TestMain

The existing MathComponent tutorial references a `main.cpp` test file
that has been replaced by an autogenerated TestMain.cpp file. The
docs have been updated to reference the TestMain file instead of
the old manually created main.cpp file.

* lestarch: updating docs to clarify *Base.* files being autocoded.

Co-authored-by: M Starch <LeStarch@googlemail.com>

docs/Tutorials/MathComponent/Tutorial.md

@@ -1085,19 +1085,19 @@ The files that are generated are:
 ```
 Tester.hpp
 Tester.cpp
-TesterBase.hpp
-TesterBase.cpp
-GTestBase.hpp
-GTestBase.cpp
+TestMain.cpp
 ```
 
+**Note:** TesterBase.* and GTestBase.* files can be removed. these will be regenerated when the unit test builds.
+
 The functions of the files are:
 
 |File|Function|
 |---|---|
-|TesterBase.*|Base class for test class. Defines necessary handlers as well as helper functions
-|GTestBase.*|Helper class derived from TesterBase that has macros that use Google Test to test interfaces|
+|TesterBase.*| Base class for test class. Defines necessary handlers as well as helper functions.  **Autocoded** |
+|GTestBase.*|Helper class derived from TesterBase that has macros that use Google Test to test interfaces.   **Autocoded** |
 |Tester.*|Derived tester class that inherits from GTestBase. Includes instance of the component and helpers to connect ports|
+|TestMain.cpp|Main unit test implementation file|
 
 Unit tests are built in subdirectories of the module, so the unit test file must be copied there. The build system supports a standard subdirectory of `test/ut` below the module being tested. While in the MathSender directory, create the `test/ut` directory:
 
@@ -1121,10 +1121,8 @@ set(SOURCE_FILES
 register_fprime_module()
 
 set(UT_SOURCE_FILES
-  "${CMAKE_CURRENT_LIST_DIR}/test/ut/main.cpp"
+  "${CMAKE_CURRENT_LIST_DIR}/test/ut/TestMain.cpp"
   "${CMAKE_CURRENT_LIST_DIR}/test/ut/Tester.cpp"
-  "${CMAKE_CURRENT_LIST_DIR}/test/ut/TesterBase.cpp"
-  "${CMAKE_CURRENT_LIST_DIR}/test/ut/GTestBase.cpp"
 )
 register_fprime_ut()
 ```
@@ -1135,7 +1133,8 @@ A `UT_MODS` variable may be set should the UT depend on modules not automaticall
 
 ##### 2.4.1.3.2 Test Code Implementation
 
-The `main.cpp` file must be added. For this test, it appears like this:
+The unit tests must be added to `TestMain.cpp`. Change the default code to appear
+like this:
 
 ```c++
 #include "Tester.hpp"
@@ -1164,7 +1163,6 @@ int main(int argc, char **argv) {
   ::testing::InitGoogleTest(&argc, argv);
   return RUN_ALL_TESTS();
 }
-
 ```
 
 F' uses the Google Test framework to run unit tests. For more information about the Google Test Framework see here:
@@ -1228,14 +1226,17 @@ The test component is instantiated here:
     NameSpace::Tester tester;
 ```
 
-This allows the component to start from an newly initialized state for each unit test.
+This allows the component to start from a newly initialized state for each unit test.
 
 The unit test is executed by calling a member function of the `tester` class:
 
 ```c++
     tester.someUnitTestFunc();
 ```
 
+> NOTE: The autogenerated `Tester.*` files include a placeholder "toDo" function. Feel
+free to leave that in or delete it.
+
 The `Tester.hpp` stub can be updated to include the declarations of the unit test functions:
 
 ```c++
@@ -1245,6 +1246,9 @@ The `Tester.hpp` stub can be updated to include the declarations of the unit tes
       // ----------------------------------------------------------------------
       // Tests
       // ----------------------------------------------------------------------
+      //! To do
+      //!
+      void toDo(void);
 
       //! Test operation command
       //!
@@ -1275,7 +1279,7 @@ Add a member function to the implementation class in `Tester.cpp` to implement t
       this->sendCmd_MS_DO_MATH(0,10,1.0,2.0,MathSenderComponentBase::ADD);
       // retrieve the message from the message queue and dispatch the command to the handler
       this->component.doDispatch();
-      // verify that that only one output port was called
+      // verify that only one output port was called
       ASSERT_FROM_PORT_HISTORY_SIZE(1);
       // verify that the math operation port was only called once
       ASSERT_from_mathOut_SIZE(1);
@@ -1321,7 +1325,6 @@ Add a member function to the implementation class in `Tester.cpp` to implement t
       // verify the expected value of the event arguments
       ASSERT_EVENTS_MS_RESULT(0,10.0);
   }
-
 ```
 
 Some highlights are: