nix: flake: add markdownlint pre-commit hook

.envrc

@@ -0,0 +1,8 @@
+use_flake() {
+  watch_file flake.nix
+  watch_file flake.lock
+  eval "$(nix print-dev-env)"
+}
+
+use flake
+eval "$shellHooks"

.gitignore

@@ -1 +1,2 @@
 /public/
+.pre-commit-config.yaml

flake.lock

@@ -0,0 +1,69 @@
+{
+  "nodes": {
+    "futils": {
+      "locked": {
+        "lastModified": 1622445595,
+        "narHash": "sha256-m+JRe6Wc5OZ/mKw2bB3+Tl0ZbtyxxxfnAWln8Q5qs+Y=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "7d706970d94bc5559077eb1a6600afddcd25a7c8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "ref": "master",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1622282707,
+        "narHash": "sha256-+GOrUDsdneUqrOm9d+9bHXjEVoVcU8tm14WGVzbt6gg=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "6933d068c5d2fcff398e802f7c4e271bbdab6705",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "pre-commit-hooks": {
+      "inputs": {
+        "flake-utils": [
+          "futils"
+        ],
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1621411868,
+        "narHash": "sha256-R+7OQ2JYFCb3E7Jl7LhRifzMVCR6Gl8R98zYsNhZtJ8=",
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "rev": "2e7fac06108b4fc81f5ff9ed9a02bc4f6ede7001",
+        "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 +1,77 @@
+{
+  description = "Ambroisie's blog";
+
+  inputs = {
+    futils = {
+      type = "github";
+      owner = "numtide";
+      repo = "flake-utils";
+      ref = "master";
+    };
+
+    # https://nixpk.gs/pr-tracker.html?pr=124808
+    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 } @ inputs:
+    futils.lib.eachDefaultSystem (system:
+      let
+        inherit (nixpkgs) lib;
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        checks = {
+          pre-commit = pre-commit-hooks.lib.${system}.run {
+            src = ./.;
+
+            hooks = {
+              nixpkgs-fmt = {
+                enable = true;
+              };
+
+              markdown-lint = {
+                enable = true;
+
+                name = "Lint each post's markdown";
+
+                entry =
+                  let
+                    pkg = pkgs.nodePackages.markdownlint-cli;
+                  in
+                  "${pkg}/bin/markdownlint";
+
+                types = [ "markdown" ];
+              };
+            };
+          };
+        };
+
+        devShell = pkgs.mkShell {
+          name = "blog";
+
+          buildInputs = with pkgs; [
+            gnumake
+            hugo
+          ];
+
+          inherit (self.checks.${system}.pre-commit) shellHook;
+        };
+      }
+    );
+}