feat(nix): add mkShell and flake-{utils,parts}

Author: dtomvan

snippets/nix.json

@@ -82,6 +82,86 @@
         ],
         "description": "Nixpkgs' stdenv.mkDerivation template"
     },
+    "pkgs.mkShell": {
+        "prefix": "mks",
+        "body": [
+            "pkgs.mkShell {",
+            "  packages = [",
+            "    $1",
+            "  ];",
+            "",
+            "  env = {",
+            "    $2",
+            "  };",
+            "",
+            "  shellHook = ''",
+            "    $3",
+            "  '';",
+            "}"
+        ],
+        "description": "mkShell template"
+    },
+    "flake-parts": {
+        "prefix": "flakeparts",
+        "body": [
+            "{",
+            "  description = \"${1:A flake}\";",
+            "",
+            "  inputs = {",
+            "    nixpkgs.url = \"github:NixOS/nixpkgs/nixos-unstable\";",
+            "    flake-parts.url = \"github:hercules-ci/flake-parts\";",
+            "    systems.url = \"github:nix-systems/default\";",
+            "  };",
+            "",
+            "  outputs =",
+            "    inputs@{ flake-parts, systems, ... }:",
+            "    flake-parts.lib.mkFlake { inherit inputs; } {",
+            "      imports = [",
+            "        $2",
+            "      ];",
+            "      systems = import systems;",
+            "      perSystem =",
+            "        {",
+            "          config,",
+            "          pkgs,",
+            "          system,",
+            "          ...",
+            "        }:",
+            "        {",
+            "          $3",
+            "        };",
+            "      flake = {",
+            "        $4",
+            "      };",
+            "    };",
+            "}"
+        ],
+        "description": "simple flake template with flake-parts"
+    },
+    "flake-utils": {
+        "prefix": "flakeutils",
+        "body": [
+            "{",
+            "  description = \"${1:A flake}\";",
+            "",
+            "  inputs = {",
+            "    nixpkgs.url = \"github:NixOS/nixpkgs/nixos-unstable\";",
+            "    systems.url = \"github:nix-systems/default\";",
+            "    flake-utils = {",
+            "      url = \"github:numtide/flake-utils\";",
+            "      inputs.systems.follows = \"systems\";",
+            "    };",
+            "    $2",
+            "  };",
+            "",
+            "  outputs = inputs @ { self, nixpkgs, flake-utils, ... }: ",
+            "    flake-utils.lib.eachDefaultSystem (system: {",
+            "      $3",
+            "    });",
+            "}"
+        ],
+        "description": "simple flake template with flake-utils"
+    },
     "meta": {
         "prefix": "meta",
         "body": [