Unverified Commit a1bf64c7 authored by Matt Sturgeon's avatar Matt Sturgeon
Browse files

nixfmt-tree: refactor impl to use `treefmt.withConfig` 

Refactor the new `nixfmt-tree` package, to make use of the new
`treefmt.withConfig` wrapper.

Breaking changes:
1. Overriding `settings` will no longer entirely replace all settings,
   instead settings are now merged as modules.
2. Adding the package to a nix shell will no longer make runtime inputs
   (such as `nixfmt`) available on the PATH, only the wrapped `treefmt`
   will be added to the shell's PATH.

Non-breaking changes:
1. Introduced `runtimeInputs`, for consistency with `treefmt.withConfig`
   and other parts of nixpkgs, such as `writeShellApplication`.
2. Introduced `nixfmtPackage` to allow specifying a different nixfmt
   package, without having to know to override `nixfmt-rfc-style`.
3. Deprecated `runtimePackages` with a warning. Use the new args
   instead.
parent a4325209

pkgs/by-name/ni/nixfmt-tree/package.nix

+75 −38
Original line number Diff line number Diff line 
{

  lib,

  runCommand,

  buildEnv,

  makeWrapper,

  writers,

  treefmt,

  nixfmt-rfc-style,

  nixfmt-tree,



  settings ? {

  settings ? { },

  runtimeInputs ? [ ],

  nixfmtPackage ? nixfmt-rfc-style,



  # NOTE: `runtimePackages` is deprecated. Use `nixfmtPackage` and/or `runtimeInputs`.

  runtimePackages ? [ nixfmtPackage ],

}@args:

let

  allRuntimeInputs = runtimePackages ++ runtimeInputs;



  # Tests whether a package's main program is nixfmt.

  isNixfmt = p: p.meta.mainProgram or null == "nixfmt";



  treefmtWithConfig = treefmt.withConfig {

    name = "nixfmt-tree";



    settings = [

      # Default settings

      {

        _file = ./package.nix;



        # Log level for files treefmt won't format

        # The default is warn, which would be too annoying for people who just care about Nix

    on-unmatched = "info";

    # Assumes the user is using Git, fails if it's not

    tree-root-file = ".git/index";

        on-unmatched = lib.mkOptionDefault "info";



    formatter.nixfmt = {

        # Assume the tree is a Git repository, will fail if it's not

        tree-root-file = lib.mkOptionDefault ".git/index";



        # NOTE: The `mkIf` condition should not be needed once `runtimePackages` is removed.

        formatter.nixfmt = lib.mkIf (lib.any isNixfmt allRuntimeInputs) {

          command = "nixfmt";

          includes = [ "*.nix" ];

        };

  },

  runtimePackages ? [

    nixfmt-rfc-style

  ],

}:

buildEnv {

  name = "nixfmt-tree";



  # Allows this derivation to be used as a shell providing both treefmt and nixfmt

  paths = [ treefmt ] ++ runtimePackages;

  pathsToLink = [ "/bin" ];



  nativeBuildInputs = [

    makeWrapper

      }

      # User supplied settings

      {

        _file = "<nixfmt-tree args>";

        imports = lib.toList settings;

      }

    ];



  postBuild = ''

    wrapProgram $out/bin/treefmt \

      --prefix PATH : $out/bin \

      --add-flags "--config-file ${writers.writeTOML "treefmt.toml" settings}"

  '';



    runtimeInputs =

      # Handle `runtimePackages` deprecation (added 2025-04-01)

      lib.warnIf (args ? runtimePackages) ''

        nixfmt-tree: overriding `runtimePackages` is deprecated, use `runtimeInputs` instead.

        Note: you do not need to supply a nixfmt package when using `runtimeInputs`, however you can override `nixfmtPackage` to a different nixfmt package.

        For additional flexibility, or to configure treefmt without nixfmt, consider using `treefmt.withConfig` instead of `nixfmt-tree`.

      '' allRuntimeInputs;

  };

in

treefmtWithConfig.overrideAttrs {

  meta = {

    mainProgram = "treefmt";

    description = "Official Nix formatter zero-setup starter using treefmt";
@@ -62,7 +78,7 @@ buildEnv { 
        ```



        You can then also use `treefmt` in a pre-commit/pre-push [Git hook](https://git-scm.com/docs/githooks)

        and `nixfmt` with your editors format-on-save feature.

        and with your editor's format-on-save feature.



      - To check formatting in CI, run the following in a checkout of your Git repository:

        ```
@@ -71,9 +87,30 @@ buildEnv { 


      For more flexibility, you can customise this package using

      ```nix

      nixfmt-tree.override {

        settings = { /* treefmt config */ };

        runtimePackages = [ /* List any formatters here */ ];

      pkgs.nixfmt-tree.override {

        settings = { /* additional treefmt config */ };

        runtimeInputs = [ /* additional formatter packages */ ];

      }

      ```



      You can achieve similar results by manually configuring `treefmt`:

      ```nix

      pkgs.treefmt.withConfig {

        runtimeInputs = [ pkgs.nixfmt-rfc-style ];



        settings = {

          # Log level for files treefmt won't format

          on-unmatched = "info";



          # Assume the tree is a Git repository, will fail if it's not

          tree-root-file = ".git/index";



          # Configure nixfmt for .nix files

          formatter.nixfmt = {

            command = "nixfmt";

            includes = [ "*.nix" ];

          };

        };

      }

      ```