Fixing off by 1 error for Negation To Substraction CodeFix

[jasiozet]

Fixing of by 1 error, using dec instead of inc.

Fixes ionide/ionide-vscode-fsharp#1657

[baronfel]

Looks good! Could you try to add a test? The tests for most code fixes are here, and are very similar in structure. Here's a rough checklist:

• create a script file in the test data folders similar to existing tests
• make a new test suite (here's an example of one: https://github.com/fsharp/FsAutoComplete/blob/main/test/FsAutoComplete.Tests.Lsp/CodeFixTests.fs#L411-L447)
• point that test suite at your test script file in the server let binding
• in your CodeActionParams, set the location to the code position that should trigger the codefix
• assert that the return value from the codefix contains the change you want to see (in this case that "- " appears at the position you expect)
• add your test suite to the list at the bottom of the file

[jasiozet]

Of course, I'll try, but this will take me a little bit longer probably.
Any idea why only one of the builds failed?

[baronfel]

The failure isn't your fault, some of the tests
on a certain component are flaky and so we take a ...probabilistic view on success.

[jasiozet]

Ok I think I managed to fix it ok

[baronfel]

Thanks for doing this @jasiozet, and congratulations on your first Pull Request ever on GitHub! I'm so happy that you chose to contribute :)

[jasiozet]

The credit goes all to you. There were 2 hard parts - setting up env, debugging on local machine & knowing were to look in the codebase - you helped me greatly with both.

Super happy to be able to do the smaller part on my own.

[baronfel]

This was released in FSAC 0.50.0 just now, and I hope to update ionide itself over the next couple days.