Ensure users don't create a .wasp file

[komyg]

Description

Fixes: #2406

Select what type of change this PR introduces:

1. Just code/docs improvement (no functional change).
2. Bug fix (non-breaking change which fixes an issue).
3. New feature (non-breaking change which adds functionality).
4. Breaking change (fix or feature that would cause existing functionality to not work as expected).

Update Waspc ChangeLog and version if needed

If you did a bug fix, new feature, or breaking change, that affects waspc, make sure you satisfy the following:

1. I updated ChangeLog.md with description of the change this PR introduces.
2. I bumped waspc version in waspc.cabal to reflect changes I introduced, with regards to the version of the latest wasp release, if the bump was needed.

Update example apps if needed

If you did code changes and added a new feature or modified an existing feature, make sure you satisfy the following:

1. I updated waspc/examples/todoApp as needed (updated modified feature or added new feature) and manually checked it works correctly.
2. I updated waspc/headless-test/examples/todoApp and its e2e tests as needed (updated modified feature and its tests or added new feature and new tests for it).

[sodic]

Hey @komyg, thanks for the effort!

You have the right idea, and I see you know how to use both Haskell and our codebase (props for using relfile and IOUtil.doesFileExist), so I have no doubt we'll be merging this soon.

There are some improvements we can do, I left three requests (the biggest of which is moving the logic into findWaspFile).

Let me know if you have any questions :)

[komyg]

Hey @sodic, thank you for your review, it was very through!

I believe I addressed most of your comments. Could you review again, please?

The only thing left is making sure we don't have more than one .wasp file. I am currently working on that, but it is not done yet. If I can get it done before your next review, then I can be a part of this PR, otherwise, I can make it into another PR. What do you think?

[komyg]

Hey @sodic, I managed to check if we have more than one *.wasp or *.wasp.ts files in the .wasp folder. Could you review again and tell me what you think, please?

[sodic]

Nice work, Felipe!

I appreciate the patience. I tried to make it up to you with a thorough review.

Let me know what you think!

[komyg]

Hey @sodic, I've refactored the code based on your suggestions.

It does look better (and more declarative) using the pattern matching you suggested, however I had to add a if to check if the file is called just .wasp or .wasp.ts, which is invalid. Maybe there is a better way to account for these cases?

Anyway, could you review again, please?

[sodic]

Hey @komyg, great work! This is almost ready.

Just a couple of small fixes and we're good to go.

About your question:

however I had to add a if to check if the file is called just .wasp or .wasp.ts, which is invalid. Maybe there is a better way to account for these cases?

if expressions are a fine way to do this, but I personally prefer guards:

(waspLangFiles, []) -> case waspLangFiles of
  [singleWaspLangFile]
    | fromRelPath (basename singleWaspLangFile) == ".wasp" -> Left "Name too short"
    | otherwise -> Right . WaspLang $ castFile (projectDir </> singleWaspLangFile)

You're free to keep the if if you like it. This is just my preference.

[komyg]

Hey @sodic, I've made the changes you requested. Can you review again, please?

[sodic]

There's just one slight regression we should fix and I'm merging.

[sodic]

All's good to go!

@komyg Great work and thanks for the fix!