Add opinionated template

Author: ulrikstrid

flake.nix

@@ -57,6 +57,14 @@
         pkgs.appendOverlays extraOverlays;
 
       overlays.default = import ./overlay nixpkgs;
+
+      templates.opinionated = {
+        description =
+          "Opinionated setup for ocaml development";
+        path = ./templates/opinionated;
+      };
+
+      templates.default = self.templates.opinionated;
     } // flake-utils.lib.eachDefaultSystem (system:
       {
         legacyPackages = self.makePkgs { inherit system; };

templates/opinionated/.ocamlformat

@@ -0,0 +1,63 @@
+{
+  nixConfig = {
+    extra-substituters = "https://ocaml.nix-cache.com";
+    extra-trusted-public-keys = "ocaml.nix-cache.com-1:/xI2h2+56rwFfKyyFVbkJSeGqSIYMC/Je+7XXqGKDIY=";
+  };
+
+  inputs = {
+    nixpkgs.url = "github:nix-ocaml/nix-overlays";
+    treefmt-nix.url = "github:numtide/treefmt-nix";
+    treefmt-nix.inputs.nixpkgs.follows = "nixpkgs";
+    nix-filter.url = "github:numtide/nix-filter";
+  };
+
+  outputs = inputs @ { flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      imports = [
+        inputs.treefmt-nix.flakeModule
+      ];
+      systems = [ "x86_64-linux" "aarch64-darwin" ];
+      perSystem =
+        { config
+        , self'
+        , inputs'
+        , pkgs
+        , system
+        , ...
+        }: {
+          treefmt = {
+            projectRootFile = "flake.nix";
+            programs = {
+              alejandra.enable = true;
+              ocamlformat = {
+                inherit pkgs;
+                configFile = ./.ocamlformat;
+                enable = true;
+              };
+            };
+          };
+
+          packages = pkgs.ocamlPackages.callPackage ./nix {
+            inherit (inputs) nix-filter;
+            doCheck = true;
+          };
+
+          devShells.default = pkgs.mkShell {
+            inputsFrom = with self'.packages; [
+              self'.packages.package
+            ];
+
+            packages = with pkgs.ocamlPackages; [
+              ocaml
+              dune
+
+              ocaml-lsp
+
+              ocamlformat
+              dune-release
+              odoc
+            ];
+          };
+        };
+    };
+}

templates/opinionated/flake.nix

@@ -0,0 +1,49 @@
+{ pkgs
+, stdenv
+, lib
+, nix-filter
+, ocamlPackages
+, static ? false
+, doCheck
+,
+}:
+with ocamlPackages; rec {
+  package = buildDunePackage {
+    pname = "package";
+    version = "1.0.0";
+
+    src = with nix-filter.lib;
+      filter {
+        # Root of the project relative to this file
+        root = ./..;
+        # If no include is passed, it will include all the paths.
+        include = [
+          # Include the "src" path relative to the root.
+          "src"
+          "test"
+          # Include this specific path. The path must be under the root.
+          ../package.opam
+          ../dune-project
+        ];
+      };
+
+    checkInputs = [
+      # Put test dependencies here
+    ];
+
+    propagatedBuildInputs = [
+      # Put dependencies here
+    ];
+
+    buildInputs = [
+      # Put build-time dependencies here
+    ];
+
+    inherit doCheck;
+
+    meta = {
+      description = "Describe your project here";
+      # license = stdenv.lib.licenses.bsd3;
+    };
+  };
+}