Folding Range

[mhanberg]

Description

Port this feature from ElixirLS

https://github.com/elixir-lsp/elixir-ls/tree/master/apps/language_server/lib/language_server/providers/folding_range

Fold reasons:

• Indentation based
• comment blocks (two or more consecutive lines)
• token pairs
  • do ... end
  • with ... do
  • for ... do
  • case ... do
  • fn ... end
  • << ... >>
  • { ... }
  • [ ... ]
  • ( ... )
• heredocs (""" ... """)
• multi-line strings
• charlist heredocs (do we need it?)
• multi-line charlist (do we need it?)
• multi-line sigils
• docs
  • moduledoc
  • typedoc
  • doc

[oaksprout]

Would you want this one done? — The Elixir language server's folding-range provider is missing folds for several documented constructs, including with/for/fn blocks, delimiter pairs, indentation blocks, and charlist heredocs, even though comments, do/end blocks, and string or sigil literals already fold. If yes, we'll do it and open a PR; if not, say so (or just ignore this) and we won't touch it.

How it works: an AI agent does the work against your write-up. Before anything reaches you, the change is rebuilt and tested from a clean copy of your project, using your own test suite, and the results are kept in a record you can check yourself. A human reviews it, submits it, and answers the review. You keep full control — nothing lands unless you merge it.

We're testing whether work offered this way is useful to maintainers — a blunt "no" is as helpful as a yes.

[sophiathedev]

I am working on a focused implementation for the remaining anonymous function folding case, adding fn ... end folding ranges and regression coverage without expanding this PR to the other unchecked constructs.