feat: align example treefmt config with flake treefmt config

Prevent unnecessary reformatting

internal/format/config_test.go

@@ -55,7 +55,7 @@ func TestConfig(t *testing.T) {
 	// nix
 	nix, ok := cfg.Formatters["nix"]
 	as.True(ok, "nix formatter not found")
-	as.Equal("nixpkgs-fmt", nix.Command)
+	as.Equal("alejandra", nix.Command)
 	as.Nil(nix.Options)
 	as.Equal([]string{"*.nix"}, nix.Includes)
 	as.Equal([]string{"examples/nix/sources.nix"}, nix.Excludes)
@@ -72,7 +72,7 @@ func TestConfig(t *testing.T) {
 	prettier, ok := cfg.Formatters["prettier"]
 	as.True(ok, "prettier formatter not found")
 	as.Equal("prettier", prettier.Command)
-	as.Equal([]string{"--write"}, prettier.Options)
+	as.Equal([]string{"--write", "--tab-width", "4"}, prettier.Options)
 	as.Equal([]string{
 		"*.css",
 		"*.html",
@@ -88,12 +88,12 @@ func TestConfig(t *testing.T) {
 	as.Equal([]string{"CHANGELOG.md"}, prettier.Excludes)
 
 	// rust
-	// rust, ok := cfg.Formatters["rust"]
-	// as.True(ok, "rust formatter not found")
-	// as.Equal("rustfmt", rust.Command)
-	// as.Equal([]string{"--edition", "2018"}, rust.Options)
-	// as.Equal([]string{"*.rs"}, rust.Includes)
-	// as.Nil(rust.Excludes)
+	rust, ok := cfg.Formatters["rust"]
+	as.True(ok, "rust formatter not found")
+	as.Equal("rustfmt", rust.Command)
+	as.Equal([]string{"--edition", "2018"}, rust.Options)
+	as.Equal([]string{"*.rs"}, rust.Includes)
+	as.Nil(rust.Excludes)
 
 	// shell
 	shell, ok := cfg.Formatters["shell"]

nix/devshell.nix

@@ -28,12 +28,11 @@
         golangci-lint
 
         # formatters for testing
-
+        alejandra
         elmPackages.elm-format
         haskellPackages.cabal-fmt
         haskellPackages.ormolu
         mdsh
-        nixpkgs-fmt
         nodePackages.prettier
         python3.pkgs.black
         rufo

nix/treefmt.nix

@@ -15,7 +15,21 @@
         statix.enable = true;
       };
 
-      settings.formatter.prettier.options = ["--tab-width" "4"];
+      settings.formatter.prettier = {
+        options = ["--tab-width" "4"];
+        includes = [
+          "*.css"
+          "*.html"
+          "*.js"
+          "*.json"
+          "*.jsx"
+          "*.md"
+          "*.mdx"
+          "*.scss"
+          "*.ts"
+          "*.yaml"
+        ];
+      };
     };
 
     devshells.default = {

test/examples/javascript/source/hello.js

@@ -46,7 +46,10 @@ const helloFactory = function ({ React }) {
                 return (
                     <p>
                         Hello,&nbsp;
-            <span style={styles.displayMode} onClick={() => setMode("edit")}>
+                        <span
+                            style={styles.displayMode}
+                            onClick={() => setMode("edit")}
+                        >
                             {word}!
                         </span>
                         <input

test/examples/nix/sources.nix

@@ -3,8 +3,7 @@ let
   #
   # The fetchers. fetch_<type> fetches specs of type <type>.
   #
-  fetch_file = pkgs: name: spec:
-    let
+  fetch_file = pkgs: name: spec: let
     name' = sanitizeName name + "-src";
   in
     if spec.builtin or true
@@ -20,8 +19,7 @@ let
         name = name';
       };
 
-  fetch_tarball = pkgs: name: spec:
-    let
+  fetch_tarball = pkgs: name: spec: let
     name' = sanitizeName name + "-src";
   in
     if spec.builtin or true
@@ -37,8 +35,7 @@ let
         inherit (spec) url sha256;
       };
 
-  fetch_git = name: spec:
-    let
+  fetch_git = name: spec: let
     ref =
       spec.ref
       or (
@@ -85,17 +82,16 @@ let
   );
 
   # The set of packages used when specs are fetched using non-builtins.
-  mkPkgs = sources: system:
-    let
+  mkPkgs = sources: system: let
     sourcesNixpkgs =
-        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) { inherit system; };
+      import (builtins_fetchTarball {inherit (sources.nixpkgs) url sha256;}) {inherit system;};
     hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
     hasThisAsNixpkgsPath = <nixpkgs> == ./.;
   in
     if builtins.hasAttr "nixpkgs" sources
     then sourcesNixpkgs
     else if hasNixpkgsPath && ! hasThisAsNixpkgsPath
-    then import <nixpkgs> { }
+    then import <nixpkgs> {}
     else
       abort
       ''
@@ -123,8 +119,7 @@ let
 
   # If the environment variable NIV_OVERRIDE_${name} is set, then use
   # the path directly as opposed to the fetched source.
-  replace = name: drv:
-    let
+  replace = name: drv: let
     saneName =
       stringAsChars
       (c:
@@ -162,7 +157,7 @@ let
   # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
   range = first: last:
     if first > last
-    then [ ]
+    then []
     else builtins.genList (n: first + n) (last - first + 1);
 
   # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
@@ -177,34 +172,28 @@ let
   optionalAttrs = cond: as:
     if cond
     then as
-    else { };
+    else {};
 
   # fetchTarball version that is compatible between all the versions of Nix
-  builtins_fetchTarball =
-    { url
-    , name ? null
-    , sha256
-    ,
-    } @ attrs:
-    let
+  builtins_fetchTarball = {
+    url,
+    name ? null,
+  } @ attrs: let
     inherit (builtins) lessThan nixVersion fetchTarball;
   in
     if lessThan nixVersion "1.12"
-    then fetchTarball ({ inherit url; } // (optionalAttrs (name != null) { inherit name; }))
+    then fetchTarball ({inherit url;} // (optionalAttrs (name != null) {inherit name;}))
     else fetchTarball attrs;
 
   # fetchurl version that is compatible between all the versions of Nix
-  builtins_fetchurl =
-    { url
-    , name ? null
-    , sha256
-    ,
-    } @ attrs:
-    let
+  builtins_fetchurl = {
+    url,
+    name ? null,
+  } @ attrs: let
     inherit (builtins) lessThan nixVersion fetchurl;
   in
     if lessThan nixVersion "1.12"
-    then fetchurl ({ inherit url; } // (optionalAttrs (name != null) { inherit name; }))
+    then fetchurl ({inherit url;} // (optionalAttrs (name != null) {inherit name;}))
     else fetchurl attrs;
 
   # Create the final "sources" from the config
@@ -216,21 +205,22 @@ let
         then
           abort
           "The values in sources.json should not have an 'outPath' attribute"
-          else spec // { outPath = replace name (fetch config.pkgs name spec); }
+        else spec // {outPath = replace name (fetch config.pkgs name spec);}
     )
     config.sources;
 
   # The "config" used by the fetchers
-  mkConfig =
-    { sourcesFile ? if builtins.pathExists ./sources.json
+  mkConfig = {
+    sourcesFile ?
+      if builtins.pathExists ./sources.json
       then ./sources.json
-      else null
-    , sources ? if (sourcesFile == null)
-      then { }
-      else builtins.fromJSON (builtins.readFile sourcesFile)
-    , system ? builtins.currentSystem
-    , pkgs ? mkPkgs sources system
-    ,
+      else null,
+    sources ?
+      if (sourcesFile == null)
+      then {}
+      else builtins.fromJSON (builtins.readFile sourcesFile),
+    system ? builtins.currentSystem,
+    pkgs ? mkPkgs sources system,
   }: rec {
     # The sources, i.e. the attribute set of spec name to spec
     inherit sources;
@@ -239,4 +229,4 @@ let
     inherit pkgs;
   };
 in
-mkSources (mkConfig { }) // { __functor = _: settings: mkSources (mkConfig settings); }
+  mkSources (mkConfig {}) // {__functor = _: settings: mkSources (mkConfig settings);}

test/treefmt.toml

@@ -27,7 +27,7 @@ includes = ["*.hs"]
 excludes = ["examples/haskell/"]
 
 [formatter.nix]
-command = "nixpkgs-fmt"
+command = "alejandra"
 includes = ["*.nix"]
 # Act as an example on how to exclude specific files
 excludes = ["examples/nix/sources.nix"]
@@ -39,7 +39,7 @@ includes = ["*.rb"]
 
 [formatter.prettier]
 command = "prettier"
-options = ["--write"]
+options = ["--write", "--tab-width", "4"]
 includes = [
     "*.css",
     "*.html",