Allow .exe executables on Windows

[shivjm]

This resolves the issue I mentioned in #110 (comment)—I have dart.exe, the library expects only dart.bat—and makes the failing tests pass on Windows.

Part of why the tests were failing is that (f-join (f-root) "/flutter") ⇒ "/flutter" even on Windows, where it should be "c:/flutter", because (f-absolute-p "/flutter") ⇒ t. I solved this by removing the leading slashes on the directories being joined to (f-root), which I believe will produce the correct result on all platforms.

[ericdallo]

Looks good, thank you for looking at the tests too

[ericdallo]

Could you fix the tests please @shivjm ?

[shivjm]

Ah, blast, I thought this would work no matter the platform. It’s tricky because I don’t have a Linux-based Emacs, but let me see if I can figure it out.

[shivjm]

I tried this with Emacs under WSL and all the tests passed. Let me try creating an Ubuntu VM and repeating the tests.

EDIT:
That let me reproduce the issue. Let’s see what I can do.

[shivjm]

I found the issue. My changes replaced file-regular-p with file-executable-p, but the files in the fixtures/ directory aren’t executable. I’ve reverted to file-regular-p, which makes the tests pass on all platforms.

My apologies for having introduced new issues!

[shivjm]

The two three failed runs look to be the result of network issues.

[jcs090218]

nix isn't very stable recently. It should be good once @ericdallo has re-run the failed jobs!

[ericdallo]

Thanks for fixing windows issues as well @shivjm!