add(nix): treefmt / alejandra (#1201)

* add(nix): treefmt / alejandra

* fmt the nix tree

* add fmt check for nix to ci

* switch `nixpkgs-fmt` -> `alejandra`

8 files changed, 231 insertions, 197 deletions

diff --git a/.github/workflows/nix.yml b/.github/workflows/nix.yml
index 44b6f826a..24b3f2845 100644
--- a/.github/workflows/nix.yml
+++ b/.github/workflows/nix.yml
@@ -9,26 +9,28 @@ on:
       - main
 
 jobs:
-  #check:
-    #runs-on: ubuntu-latest
-    #name: "flake check"
-    #environment: cachix
-    #timeout-minutes: 5
-    #steps:
-      #- uses: actions/checkout@v3
-        #with:
-          ## Nix Flakes doesn't work on shallow clones
-          #fetch-depth: 0
-      #- uses: cachix/install-nix-action@v16
-        #with:
-          #extra_nix_config: |
-            #experimental-features = nix-command flakes
-          #fetch-depth: 0
-      #- uses: cachix/cachix-action@v10
-        #with:
-          #name: zellij
-          ## If you chose API tokens for write access OR if you have a private cache
-          #authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+  check:
+    runs-on: ubuntu-latest
+    name: "flake check"
+    environment: cachix
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          # Nix Flakes doesn't work on shallow clones
+          fetch-depth: 0
+      - uses: cachix/install-nix-action@v16
+        with:
+          extra_nix_config: |
+            experimental-features = nix-command flakes
+          fetch-depth: 0
+      - uses: cachix/cachix-action@v10
+        with:
+          name: zellij
+          # If you chose API tokens for write access OR if you have a private cache
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+      - run: nix develop .#fmtShell --command treefmt --fail-on-change
+      ## nix flake check still fails on IFD
       #- run: nix flake check --print-build-logs --show-trace
 
   build:
diff --git a/default.nix b/default.nix
index 873ece493..78bc3a1f6 100644
--- a/default.nix
+++ b/default.nix
@@ -1,13 +1,14 @@
 (import
-  (
-    let
-      lock = builtins.fromJSON (builtins.readFile ./flake.lock);
-    in
+(
+  let
+    lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+  in
     fetchTarball {
       url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
       sha256 = lock.nodes.flake-compat.locked.narHash;
     }
-  )
-  {
-    src = ./.;
-  }).defaultNix
+)
+{
+  src = ./.;
+})
+.defaultNix
diff --git a/flake.nix b/flake.nix
index 6e01933d6..475c4d084 100644
--- a/flake.nix
+++ b/flake.nix
@@ -14,5 +14,5 @@
     crate2nix.flake = false;
   };
 
-    outputs = { ... } @ args: import ./nix args;
+  outputs = {...} @ args: import ./nix args;
 }
diff --git a/nix/crate2nix.nix b/nix/crate2nix.nix
index 435627d4a..fc2ce4eb5 100644
--- a/nix/crate2nix.nix
+++ b/nix/crate2nix.nix
@@ -1,34 +1,35 @@
-{ pkgs
-, crate2nix
-, name
-, src
-, postInstall
-, nativeBuildInputs
-, desktopItems
-, meta
-}:
-
-let
-  inherit (import "${crate2nix}/tools.nix" { inherit pkgs; })
-    generatedCargoNix;
+{
+  pkgs,
+  crate2nix,
+  name,
+  src,
+  postInstall,
+  nativeBuildInputs,
+  desktopItems,
+  meta,
+}: let
+  inherit
+    (import "${crate2nix}/tools.nix" {inherit pkgs;})
+    generatedCargoNix
+    ;
 
   project = import
-    (generatedCargoNix {
-        inherit name src;
-    })
-    {
-      inherit pkgs;
-      buildRustCrateForPkgs = pkgs:
-        pkgs.buildRustCrate.override {
-          defaultCrateOverrides = pkgs.defaultCrateOverrides // {
+  (generatedCargoNix {
+    inherit name src;
+  })
+  {
+    inherit pkgs;
+    buildRustCrateForPkgs = pkgs:
+      pkgs.buildRustCrate.override {
+        defaultCrateOverrides =
+          pkgs.defaultCrateOverrides
+          // {
             # Crate dependency overrides go here
             zellij = attrs: {
               inherit postInstall desktopItems meta name nativeBuildInputs;
-
             };
           };
-        };
-    };
-
+      };
+  };
 in
-project.workspaceMembers.zellij.build
+  project.workspaceMembers.zellij.build
diff --git a/nix/default.nix b/nix/default.nix
index f7c59d484..18f56f841 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -1,9 +1,10 @@
-{ self
-, nixpkgs
-, rust-overlay
-, flake-utils
-, flake-compat
-, crate2nix
+{
+  self,
+  nixpkgs,
+  rust-overlay,
+  flake-utils,
+  flake-compat,
+  crate2nix,
 }:
 flake-utils.lib.eachSystem [
   "aarch64-linux"
@@ -12,128 +13,153 @@ flake-utils.lib.eachSystem [
   "x86_64-darwin"
   "x86_64-linux"
 ]
-  (system:
-    let
-      overlays = [ (import rust-overlay) ];
-
-      pkgs = import nixpkgs { inherit system overlays; };
-
-      crate2nixPkgs = import nixpkgs { inherit system;
-      overlays = [
-          (self: _: {
-            rustc = rustToolchainToml;
-            cargo = rustToolchainToml;
-          })
-
-      ];};
-
-      name = "zellij";
-      pname = name;
-      root = toString ../.;
-
-      ignoreSource = [ ".git" "target" "example" ];
-
-      src = pkgs.nix-gitignore.gitignoreSource ignoreSource root;
-
-      rustToolchainToml = pkgs.rust-bin.fromRustupToolchainFile ../rust-toolchain;
-      cargoLock = {
-        lockFile = (builtins.path { path = ../Cargo.lock; name = "Cargo.lock"; });
-      };
-      cargo = rustToolchainToml;
-      rustc = rustToolchainToml;
-
-      buildInputs = [
-        rustToolchainToml
-
-        # in order to run tests
-        pkgs.openssl
-      ];
-
-      nativeBuildInputs = [
-        # generates manpages
-        pkgs.mandown
-
-        pkgs.installShellFiles
-        pkgs.copyDesktopItems
-
-        # for openssl/openssl-sys
-        pkgs.pkg-config
-      ];
-
-      devInputs = [
-        pkgs.cargo-make
-        pkgs.rust-analyzer
-        pkgs.nixpkgs-fmt
-
-        # optimizes wasm binaries
-        pkgs.binaryen
-
-        # used for snapshotting the e2e tests
-        pkgs.cargo-insta
-      ];
-
-      postInstall = ''
-        mandown ./docs/MANPAGE.md > ./zellij.1
-        installManPage ./zellij.1
-
-        # explicit behavior
-        $out/bin/zellij setup --generate-completion bash > ./completions.bash
-        installShellCompletion --bash --name ${pname}.bash ./completions.bash
-        $out/bin/zellij setup --generate-completion fish > ./completions.fish
-        installShellCompletion --fish --name ${pname}.fish ./completions.fish
-        $out/bin/zellij setup --generate-completion zsh > ./completions.zsh
-        installShellCompletion --zsh --name _${pname} ./completions.zsh
-
-        install -Dm644  ./assets/logo.png $out/share/icons/hicolor/scalable/apps/zellij.png
-
-        copyDesktopItems
-      '';
-
-      desktopItems = [
-        (pkgs.makeDesktopItem {
-          type = "Application";
-          inherit name;
-          desktopName = "zellij";
-          terminal = true;
-          genericName = "Terminal multiplexer";
-          comment = "Manage your terminal applications";
-          exec = "zellij";
-          icon = "zellij";
-          categories = [ "ConsoleOnly;System" ];
-        })
-      ];
-      meta = with pkgs.lib; {
-        homepage = "https://github.com/zellij-org/zellij/";
-        description = "A terminal workspace with batteries included";
-        license = [ licenses.mit ];
-      };
-    in
-    rec {
-
-      # crate2nix - better incremental builds, but uses ifd
-      packages.zellij = crate2nixPkgs.callPackage ./crate2nix.nix {
-          inherit crate2nix name src desktopItems postInstall
-          meta nativeBuildInputs;
-      };
-
-      # native nixpkgs support - keep supported
-      packages.zellij-native =
-        (pkgs.makeRustPlatform { inherit cargo rustc; }).buildRustPackage {
-            inherit src name cargoLock
-            buildInputs nativeBuildInputs
-            postInstall desktopItems meta;
-        };
-
-      defaultPackage = packages.zellij;
-
-      # nix run
-      apps.zellij = flake-utils.lib.mkApp { drv = packages.zellij; };
-      defaultApp = apps.zellij;
-
-
-      devShell = pkgs.callPackage ./devShell.nix {
-        inherit buildInputs;
-        nativeBuildInputs = nativeBuildInputs ++ devInputs;
-      };
-
+(system: let
+  overlays = [(import rust-overlay)];
+
+  pkgs = import nixpkgs {inherit system overlays;};
+
+  crate2nixPkgs = import nixpkgs {
+    inherit system;
+    overlays = [
+      (self: _: {
+        rustc = rustToolchainToml;
+        cargo = rustToolchainToml;
+      })
+    ];
+  };
+
+  name = "zellij";
+  pname = name;
+  root = toString ../.;
+
+  ignoreSource = [".git" "target" "example"];
+
+  src = pkgs.nix-gitignore.gitignoreSource ignoreSource root;
+
+  rustToolchainToml = pkgs.rust-bin.fromRustupToolchainFile ../rust-toolchain;
+  cargoLock = {
+    lockFile = (builtins.path {
+      path = ../Cargo.lock;
+      name = "Cargo.lock";
+    });
+  };
+  cargo = rustToolchainToml;
+  rustc = rustToolchainToml;
+
+  buildInputs = [
+    rustToolchainToml
+
+    # in order to run tests
+    pkgs.openssl
+  ];
+
+  nativeBuildInputs = [
+    # generates manpages
+    pkgs.mandown
+
+    pkgs.installShellFiles
+    pkgs.copyDesktopItems
+
+    # for openssl/openssl-sys
+    pkgs.pkg-config
+  ];
+
+  devInputs = [
+    pkgs.cargo-make
+    pkgs.rust-analyzer
+
+    # optimizes wasm binaries
+    pkgs.binaryen
+
+    # used for snapshotting the e2e tests
+    pkgs.cargo-insta
+  ];
+
+  fmtInputs = [
+    pkgs.alejandra
+    pkgs.treefmt
+  ];
+
+  postInstall = ''
+    mandown ./docs/MANPAGE.md > ./zellij.1
+    installManPage ./zellij.1
+
+    # explicit behavior
+    $out/bin/zellij setup --generate-completion bash > ./completions.bash
+    installShellCompletion --bash --name ${pname}.bash ./completions.bash
+    $out/bin/zellij setup --generate-completion fish > ./completions.fish
+    installShellCompletion --fish --name ${pname}.fish ./completions.fish
+    $out/bin/zellij setup --generate-completion zsh > ./completions.zsh
+    installShellCompletion --zsh --name _${pname} ./completions.zsh
+
+    install -Dm644  ./assets/logo.png $out/share/icons/hicolor/scalable/apps/zellij.png
+
+    copyDesktopItems
+  '';
+
+  desktopItems = [
+    (pkgs.makeDesktopItem {
+      type = "Application";
+      inherit name;
+      desktopName = "zellij";
+      terminal = true;
+      genericName = "Terminal multiplexer";
+      comment = "Manage your terminal applications";
+      exec = "zellij";
+      icon = "zellij";
+      categories = ["ConsoleOnly;System"];
     })
+  ];
+  meta = with pkgs.lib; {
+    homepage = "https://github.com/zellij-org/zellij/";
+    description = "A terminal workspace with batteries included";
+    license = [licenses.mit];
+  };
+in rec {
+  # crate2nix - better incremental builds, but uses ifd
+  packages.zellij = crate2nixPkgs.callPackage ./crate2nix.nix {
+    inherit
+      name
+      src
+      nativeBuildInputs
+      crate2nix
+      desktopItems
+      postInstall
+      meta
+      ;
+  };
+
+  # native nixpkgs support - keep supported
+  packages.zellij-native =
+    (pkgs.makeRustPlatform {inherit cargo rustc;}).buildRustPackage {
+      inherit
+        src
+        name
+        cargoLock
+        buildInputs
+        nativeBuildInputs
+        postInstall
+        desktopItems
+        meta
+        ;
+    };
+
+  defaultPackage = packages.zellij;
+
+  # nix run
+  apps.zellij = flake-utils.lib.mkApp {drv = packages.zellij;};
+  defaultApp = apps.zellij;
+
+  devShells = {
+    zellij = pkgs.callPackage ./devShell.nix {
+      inherit buildInputs;
+      nativeBuildInputs = nativeBuildInputs ++ devInputs ++ fmtInputs;
+    };
+    fmtShell = pkgs.mkShell {
+      name = "fmt-shell";
+      nativeBuildInputs = fmtInputs;
+    };
+  };
+
+  devShell = devShells.zellij;
+})
diff --git a/nix/devShell.nix b/nix/devShell.nix
index 86850e709..261234f65 100644
--- a/nix/devShell.nix
+++ b/nix/devShell.nix
@@ -1,8 +1,8 @@
-{ mkShell
-, buildInputs
-, nativeBuildInputs
+{
+  mkShell,
+  buildInputs,
+  nativeBuildInputs,
 }:
-
 mkShell {
   name = "zj-dev-env";
   inherit buildInputs nativeBuildInputs;
diff --git a/shell.nix b/shell.nix
index 9eb132a58..a3b4d7607 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,13 +1,14 @@
 (import
-  (
-    let
-      lock = builtins.fromJSON (builtins.readFile ./flake.lock);
-    in
+(
+  let
+    lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+  in
     fetchTarball {
       url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
       sha256 = lock.nodes.flake-compat.locked.narHash;
     }
-  )
-  {
-    src = ./.;
-  }).shellNix
+)
+{
+  src = ./.;
+})
+.shellNix
diff --git a/treefmt.toml b/treefmt.toml
new file mode 100644
index 000000000..fe5d1f37e
--- /dev/null
+++ b/treefmt.toml
@@ -0,0 +1,3 @@
+[formatter.nix]
+command = "alejandra"
+includes = ["*.nix"]