flake: replaced shell nix with flake

Signed-off-by: aserowy <[email protected]>

.envrc

@@ -1 +1 @@
-use_nix
+use flake

flake.nix

@@ -0,0 +1,54 @@
+{
+  description = "tmux.nvim env";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+          config.allowUnfree = true;
+        };
+      in
+      with pkgs; {
+        devShell =
+          pkgs.mkShell {
+            buildInputs = [
+              gh
+              lua51Packages.busted
+              lua51Packages.luacov
+              lua51Packages.luacheck
+              nixpkgs-fmt
+              nodePackages.dockerfile-language-server-nodejs
+              nodePackages.markdownlint-cli
+              nodePackages.prettier
+              stylua
+              sumneko-lua-language-server
+            ];
+            shellHook = ''
+              export LUA_PATH="$PWD/?.lua;$PWD/lua/?/init.lua;$PWD/lua/?.lua;$LUA_PATH"
+
+              FULLPATH=$(realpath $0)
+              BASEDIR=$(dirname $FULLPATH)
+
+              # test environment
+              alias tb="docker build -t tmnv-te $BASEDIR/.dev"
+              alias te="docker run -it -v $BASEDIR:/workspace tmnv-te"
+
+              # format and check -> fac :)
+              alias fac="prettier --write README.md \
+                  && stylua .dev/ \
+                  && luacheck .dev/ \
+                  && stylua lua/ \
+                  && luacheck lua/ \
+                  && stylua spec/ \
+                  && luacheck spec/ \
+                  && busted --verbose -c"
+            '';
+          };
+      });
+}