nix: setup flake w/ pre-commit

flake.lock

@@ -0,0 +1,69 @@
+{
+  "nodes": {
+    "futils": {
+      "locked": {
+        "lastModified": 1629284811,
+        "narHash": "sha256-JHgasjPR0/J1J3DRm4KxM4zTyAj4IOJY8vIl75v/kPI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c5d161cc0af116a2e17f54316f0bf43f0819785c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "ref": "master",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1629292755,
+        "narHash": "sha256-5xMo32NVLnloY9DveqwJO/Cab1+PbTMPqU4WMmawX5M=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "253aecf69ed7595aaefabde779aa6449195bebb7",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "pre-commit-hooks": {
+      "inputs": {
+        "flake-utils": [
+          "futils"
+        ],
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1624971177,
+        "narHash": "sha256-Amf/nBj1E77RmbSSmV+hg6YOpR+rddCbbVgo5C7BS0I=",
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "rev": "397f0713d007250a2c7a745e555fa16c5dc8cadb",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "ref": "master",
+        "repo": "pre-commit-hooks.nix",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "futils": "futils",
+        "nixpkgs": "nixpkgs",
+        "pre-commit-hooks": "pre-commit-hooks"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,99 @@
+{
+  description = "A simple calculator";
+
+  inputs = {
+    futils = {
+      type = "github";
+      owner = "numtide";
+      repo = "flake-utils";
+      ref = "master";
+    };
+
+    nixpkgs = {
+      type = "github";
+      owner = "NixOS";
+      repo = "nixpkgs";
+      ref = "nixos-unstable";
+    };
+
+    pre-commit-hooks = {
+      type = "github";
+      owner = "cachix";
+      repo = "pre-commit-hooks.nix";
+      ref = "master";
+      inputs = {
+        flake-utils.follows = "futils";
+        nixpkgs.follows = "nixpkgs";
+      };
+    };
+  };
+
+  outputs = { self, futils, nixpkgs, pre-commit-hooks }:
+    futils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+      in
+      {
+        checks = {
+          inherit (self.packages.${system}) abacus;
+
+          pre-commit = pre-commit-hooks.lib.${system}.run {
+            src = self;
+
+            hooks = {
+              nixpkgs-fmt = {
+                enable = true;
+              };
+
+              clang-format = {
+                enable = true;
+                name = "clang-format";
+                entry = "${pkgs.clang-tools}/bin/clang-format -style=file -i";
+                types = [ "text" "c++" ];
+                language = "system";
+              };
+            };
+          };
+        };
+
+        defaultPackage = self.packages.${system}.abacus;
+
+        devShell = pkgs.mkShell {
+          inherit (self.defaultPackage.${system})
+            buildInputs
+            nativeBuildInputs
+            ;
+
+          inherit (self.checks.${system}.pre-commit) shellHook;
+        };
+
+        packages = futils.lib.flattenTree {
+          abacus = pkgs.stdenv.mkDerivation {
+            pname = "abacus";
+            version = "0.0.0";
+
+            src = self;
+
+            nativeBuildInputs = with pkgs; [
+              bison
+              flex
+              meson
+              ninja
+              pkg-config
+            ];
+
+            buildInputs = with pkgs; [
+              gtest
+            ];
+
+            meta = with pkgs.lib; {
+              description = "A simple calculator using big numbers";
+              homepage = "https://gitea.belanyi.fr/ambroisie/abacus";
+              license = licenses.mit;
+              maintainers = [ ambroisie ];
+              platforms = platforms.unix;
+            };
+          };
+        };
+      });
+}