Component: Refactors

[StachuDotNet]

This issue is to organize work related to Darklang's "refactors" - (usually) editor functionality of augmenting some code based on AST manipulations.

We should advance the language and editor a bit more before advancing here.

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How refactors should be applied (general)

• refactors should manipulate ASTs, and be written in Dark
• (?) only applicable if they pass some AST query
• users should be able to highlight some code and explicitly refactor it with commands
• users should be able to see a list of suggested refactors in-editor
• we should support some process that crawls throughout a user's code-base making recommendations for more substantial refactors and improvements
• use AI to help collect and perform refactors (maybe some refactors call upon a prompt rather than manipulate ASTs directly)

Common refactors to include

• TODO: review all of the commands available in dark-classic
• fix: extract variable should select the variable so that we can edit its name
• inline a variable
  • old note: "Add a command to the command palette to inline a variable. Should be a straightforward addition with code in client/src/fluid/Commands.ml and tests in client/test/fluid_command_test.ml"
• extract all uses of an expression (see #2702)
• add / remove pipes
  • If you have a |> b |> c, convert it to (c (b a)). And vice versa.
  • Most useful if you have (func value) and you want to start piping.
• wrap in if
• wrap in match
• convert if to match