feat: add Nix development environment (#441)

Author: psteinroe

README.md

@@ -33,6 +33,21 @@ Our current focus is on refining and enhancing these core features while buildin
 - [psteinroe](https://github.com/psteinroe)
 - [juleswritescode](https://github.com/juleswritescode)
 
+## Development
+
+### Using Nix
+
+```bash
+nix develop
+docker-compose up -d
+```
+
+### Using Docker
+
+```bash
+docker-compose up -d
+```
+
 ## Acknowledgements
 
 A big thanks to the following projects, without which this project wouldn't have been possible:

flake.lock

@@ -0,0 +1,92 @@
+{
+  description = "PostgreSQL Language Server Development Environment";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = { self, nixpkgs, flake-utils, rust-overlay }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        overlays = [ (import rust-overlay) ];
+        pkgs = import nixpkgs {
+          inherit system overlays;
+        };
+
+        # Read rust-toolchain.toml to get the exact Rust version
+        rustToolchain = pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+
+        # Development dependencies
+        buildInputs = with pkgs; [
+          # Rust toolchain
+          rustToolchain
+          
+          # Node.js ecosystem
+          bun
+          nodejs_20
+          
+          # Python for additional tooling
+          python3
+          python3Packages.pip
+          
+          # System dependencies
+          pkg-config
+          openssl
+          
+          # Build tools
+          just
+          git
+          
+          # LSP and development tools
+          rust-analyzer
+          
+          # Additional tools that might be needed
+          cmake
+          gcc
+          libiconv
+        ];
+        
+        # Environment variables
+        env = {
+          RUST_SRC_PATH = "${rustToolchain}/lib/rustlib/src/rust/library";
+          PKG_CONFIG_PATH = "${pkgs.openssl.dev}/lib/pkgconfig";
+        };
+
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          inherit buildInputs;
+          
+          shellHook = ''
+            echo "PostgreSQL Language Server Development Environment"
+            echo "Available tools:"
+            echo "  • Rust $(rustc --version)"
+            echo "  • Node.js $(node --version)"
+            echo "  • Bun $(bun --version)"
+            echo "  • Just $(just --version)"
+            echo ""
+            echo "Development Commands:"
+            echo "  • just --list   # Show tasks"
+            echo "  • cargo check   # Check Rust"
+            echo "  • bun install   # Install deps"
+            echo ""
+            echo "Use Docker for database:"
+            echo "  • docker-compose up -d"
+            echo ""
+            
+            # Set environment variables
+            ${pkgs.lib.concatStringsSep "\n" 
+              (pkgs.lib.mapAttrsToList (name: value: "export ${name}=\"${value}\"") env)}
+          '';
+        };
+
+        # Formatter for nix files
+        formatter = pkgs.nixfmt-rfc-style;
+      }
+    );
+}