Code actions/fixes for common edits

[majastrz]

We should consider adding code actions or commands to make common edits in Bicep. For example, parameters could allow actions like the following:

• Make it secure (strings and objects only - adds the @secure decorator above it)
• Add allowed values (adds an empty @allowed snippet and moves the cursor to the first item in the array)
• creating a loop/set of resources from an existing one
• ...

[nilshedstrom]

In this file I create a new rule that provides a fix to add the @secure decorator to parameters of type string and object.
It seems to work fine. The problem is that I get a blue squiggly for the row which seems to indicate that there is something wrong with it. I would like to provide a code action not indicate that there is an error on the line.

I know how to provide code actions in typescript.
Is there a way to provide code actions (without blue squigglies) in the language server or should I implement the change in typescript instead?

@StefanIvemo
@StephenWeatherford

[StephenWeatherford]

@nilshedstrom Hey Nils. I'm afraid the linter was not designed for this - it returns diagnostics. What we need for code refactorings is to create a code actions provider (vscode.languages.registerCodeActionsProvider). It would need to be hooked up to synchronize with the language server compiler.

@majastrz @anthony-c-martin This was marked as a good first issue, but it seems to me it will need some preparatory work first. After that, adding new refactorings ought to be fairly straightforward (we were just talking today about refactorings).

@nilshedstrom We want to avoid doing work in typescript for Bicep because it would be restricted to vscode. If it's kept in the language server, it can be reused for other editors (that wasn't possible when the ARM Tools extension was started).

[nilshedstrom]

@majastrz @anthony-c-martin This was marked as a good first issue, but it seems to me it will need some preparatory work first. After that, adding new refactorings ought to be fairly straightforward (we were just talking today about refactorings).

Ok. Tell me when I can start working on this issue.

[anthony-c-martin]

@nilshedstrom - I've pushed a branch here: https://github.com/Azure/bicep/compare/ant/codefix to serve as an example. Feel free to take this code and fork it for a starting point!

Note that my implementation for SecureParameterCodeFixProvider.cs is not robust - really intended to just provide an example of looking for a particular piece of syntax (parameter declaration), and suggesting a rewrite for it.

Let me know if you have any questions :)

Here's a demo of this code in action:

Screen.Recording.2021-12-08.at.11.12.44.PM.mov

[nilshedstrom]

Thanks @anthony-c-martin!
I have created a more robust version based on your code.

I do not find a way to set the cursor when providing a quick fix (this was requested in this issue when adding the allowed decorator).
It would probably be useful to set the cursor when adding the decorator description, maxLength, maxValue, minLength and minValue too.

[anthony-c-martin]

@nilshedstrom - looks like moving the cursor in a codeAction is unfortunately not supported; it has been requested in microsoft/language-server-protocol#724.

[anthony-c-martin]

Closing this issue as we now have support for parameter decorators (thanks @nilshedstrom!). Going forwards, I suggest we create separate issues for each code fix idea.

[StephenWeatherford]

Re-opening/reverting, the PR has failing suites.

[anthony-c-martin]

Closing again - the PR was eventually re-merged 😄