heat.exe autogenerating file fragments - every build?

Question

I'm using heat.exe to generate WiX file fragments.

I've done this via adding a post build step to my web site project in visual studio, such that every time a build is done, any new files in the web project are picked up and new wxs file fragments are created. These file fragments are copied directly into the wix setup project, such that when the setup project is built, it will include all the newly added content files into the msi.

I noted last time I looked that every time heat.exe regenerates the wxs file fragments, it creates new guids (but apparently not new component ids).

At any rate, I'm very new to WiX/heat, so the question is - should I be autogenerating the wxs files every time, e.g. how will this effect things in production when new versions of the website are released and installed/uninstalled? are there any reasons why I should not be autogenerating and including these file fragments on every build?

Answer 1

There are two main lines of thought on this sort of scenario; which one you follow depends on which risk freaks you out more. Do you worry more that you may not include some changes which become necessary in the future because nobody tells you and you didn't update your one-time generation, or do you worry more that two .msi files created with results from autogeneration will not upgrade well not let you know if important files go missing?

Personally I tend towards believing that autogeneration results in harder-to-fix problems, so I would suggest generating these only when you know something has changed, and then verifying the differences are what you expect.