Add FileCreators.generateCabalFile unit tests.

[m-renaud]

I'll be switching cabal init to use PrettyField in an upcoming PR, this will make it easier to verify that the output remains approximately the same (modulo better formatting).

[phadej]

This is great 👍

[phadej]

Please merge when CI is green

[m-renaud]

Alright, lets see if I can get those metadata checks to pass. It's currently not possible to run the make gen-extra-source-files tool, there's a base version conflict since cabal-dev-scripts.cabal has the constraints base >=4.10 && <4.13 but the rest of the packages have <4.14. Should I just bump the upper bound to <4.14 there as well?

[phadej]

Let's allow only one-two GHC versions for development tools, I guess GHC-8.8 is "safe" to use now, yet I (and CI) still use 8.6. So base >=4.12 && <4.14.

That said. I'm not keen to upgrade the GHC used for cabal development tools too often. So we'll lag behind the "newest and shinest" GHC. I'm happy to add with-compiler: ghc-8.6.5 to cabal.project.meta.

[m-renaud]

Gotcha, I got the tests passing anyways so lets leave the tools as is. Just waiting for the last checks to finish then I'll merge.

[m-renaud]

Edit: nvm, UI was out of date, appear to have done the same thing (as expected).

Hmmmmmmmm, it appears that "Merge" on the official GitHub mobile app does not do the same thing as "Merge" from the web interface 😕 Seems to not have created a merge commit for the PR, bizarre, guess I won't be doing that again.