feat: add rust and yarn to nix devShell (#1953)

by default, we assume people would like develop the language server and
editor tools. The building of tinymist-cli is moved to the neovim shell.

contrib/nix/dev/flake.nix

@@ -2,13 +2,24 @@
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
     flake-parts.url = "github:hercules-ci/flake-parts";
+    fenix = {
+      url = "github:nix-community/fenix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    rust-manifest = {
+      url = "https://static.rust-lang.org/dist/channel-rust-1.85.1.toml";
+      flake = false;
+    };
   };
 
-  outputs = inputs @ { self, flake-parts, nixpkgs, }:
+  outputs = inputs @ { self, flake-parts, nixpkgs, fenix, rust-manifest, }:
     flake-parts.lib.mkFlake { inherit inputs; } {
-      systems = ["x86_64-linux"];
-      perSystem = {config, lib, pkgs, ...}: 
-      let tinymist = pkgs.rustPlatform.buildRustPackage (finalAttrs: {
+      systems = [ "x86_64-linux" ];
+    
+      perSystem = {config, lib, pkgs, system, ...}: 
+      let
+        rust-toolchain = (fenix.packages.${system}.fromManifestFile rust-manifest).defaultToolchain;
+        tinymist = pkgs.rustPlatform.buildRustPackage (finalAttrs: {
           pname = "tinymist";
           # Please update the corresponding vscode extension when updating
           # this derivation.
@@ -82,6 +93,18 @@
       in {
         # export the project devshell as the default devshell
         devShells.default = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            rust-analyzer
+            nodejs_24
+            (yarn.override { nodejs = nodejs_24; })
+          ];
+
+          shellHook = ''
+            echo "Docs: docs/tinymist/nix.typ."
+          '';
+        };
+        # Developing neovim integration requires a fresh tinymist binary
+        devShells.neovim = pkgs.mkShell {
           buildInputs = [
             tinymist
           ];

flake.lock

@@ -1,5 +1,27 @@
 {
   "nodes": {
+    "fenix": {
+      "inputs": {
+        "nixpkgs": [
+          "tinymist-dev",
+          "nixpkgs"
+        ],
+        "rust-analyzer-src": "rust-analyzer-src"
+      },
+      "locked": {
+        "lastModified": 1753944209,
+        "narHash": "sha256-dcGdqxhRRGoA/S38BsWOrwIiLYEBOqXKauHdFwKR310=",
+        "owner": "nix-community",
+        "repo": "fenix",
+        "rev": "5ef8607d6e8a08cfb3946aaacaa0494792adf4ae",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "fenix",
+        "type": "github"
+      }
+    },
     "flake-parts": {
       "inputs": {
         "nixpkgs-lib": "nixpkgs-lib"
@@ -273,6 +295,35 @@
         "tinymist-unstable": "tinymist-unstable"
       }
     },
+    "rust-analyzer-src": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1753838657,
+        "narHash": "sha256-4FA7NTmrAqW5yt4A3hhzgDmAFD0LbGRMGKhb1LBSItI=",
+        "owner": "rust-lang",
+        "repo": "rust-analyzer",
+        "rev": "8611b714597c89b092f3d4874f14acd3f72f44fd",
+        "type": "github"
+      },
+      "original": {
+        "owner": "rust-lang",
+        "ref": "nightly",
+        "repo": "rust-analyzer",
+        "type": "github"
+      }
+    },
+    "rust-manifest": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-hqDb78PazBKoHw8IJqOfiiR2kBI1VTzo+HiPSswf4zk=",
+        "type": "file",
+        "url": "https://static.rust-lang.org/dist/channel-rust-1.85.1.toml"
+      },
+      "original": {
+        "type": "file",
+        "url": "https://static.rust-lang.org/dist/channel-rust-1.85.1.toml"
+      }
+    },
     "systems": {
       "locked": {
         "lastModified": 1681028828,
@@ -305,8 +356,10 @@
     },
     "tinymist-dev": {
       "inputs": {
+        "fenix": "fenix",
         "flake-parts": "flake-parts_2",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "rust-manifest": "rust-manifest"
       },
       "locked": {
         "path": "contrib/nix/dev",

flake.nix

@@ -20,6 +20,8 @@
         devShells = {
           # nix develop
           default = tinymist-dev.devShells.${system}.default;
+          # nix develop .#neovim
+          neovim = tinymist-dev.devShells.${system}.neovim;
           # nix develop .#unstable
           unstable = tinymist-unstable.devShells.${system}.default;
           # nix develop .#nixvim