Formatting Team Meeting 2025-05-13

jfly · May 13, 2025, 8:16pm

Formatting Team Meeting 2025-05-13

Team info
All meeting notes
Team attendees: @jfly @infinisil @MattSturgeon
Other attendees: @brianmcgee @zimbatm

Thanks to the treefmt team for attending this meeting!

Agenda & Notes

@jfly:
- stdin support: `nix fmt` broken · Issue #301 · NixOS/nixfmt · GitHub
  - The current behavior (read from stdin when no args are passed) is probably historical
  - Let’s add a --stdin spec to treefmt, and update nixfmt to honor it:
    - If --stdin is specified, then you must pass exactly 1 argument: the filename
    - `treefmt --stdin` doesn't work if the underlying formatter cares about the real filename · Issue #573 · numtide/treefmt · GitHub
- our installation/IDE configuration docs: Better installation/editor configuration instructions · Issue #303 · NixOS/nixfmt · GitHub
  - This is definitely not a nixfmt issue, it’s arguably more general than treefmt, it’s kind of a nix usage issue.
  - @brianmcgee is motivated to write a blog post about this
  - @zimbatm: this is not a treefmt itssue, it’s a more of a direnv issue. He has spent a while explaining this to the Zed editor folks, and they’re on board with it.
    - direnv needs more maintainers!
    - @jfly to schedule time with @zimbatm to discuss docs.
- We discussed the relationship between nixpkg’s treefmt.withConfig and treefmt-nix: Proposal: upstream this project to nixpkgs · Issue #349 · numtide/treefmt-nix · GitHub
@emilazy asked for an update on Change formatting for `++`, `+` and `//` by Sereja313 · Pull Request #284 · NixOS/nixfmt · GitHub (addressing Appending an optional string / array causes the entire expression to be reformatted · Issue #228 · NixOS/nixfmt · GitHub)
- @piegames is swamped. @Sereja313 will chip away at this.
- Discusssed if this is a blocker for a stable 1.0 release. We decided not, but to highlight anticipated changes in the release notes, which can double as a call for help
- Regarding version numbering, we should consider our CLI to be our interface, e.g. uremoving a --arg would be a “breaking” change
@brianmcgee mentioned: nixfmt-tree can be updated to no longer set tree-root-file once treefmt’s next release is in nixpkgs (2.3? 2.2.2?)
Discussed some proposed formatting changes:
- Preserving empty lines before a semicolon is a bit strange · Issue #298 · NixOS/nixfmt · GitHub
- Consider removing empty lines from empty attrset · Issue #299 · NixOS/nixfmt · GitHub
@jfly to review treefmt: refactor `withConfig` and `buildConfig` to use `evalConfig` by MattSturgeon · Pull Request #406685 · NixOS/nixpkgs · GitHub