generated code to offer nix-develop as version manager

jekyll/version-managers.markdown

@@ -31,6 +31,32 @@ Ensure Mise is up-to-date: https://mise.jdx.dev/faq.html#mise-is-failing-or-not-
 
 Ensure RVM is up-to-date: https://rvm.io/rvm/upgrading
 
+## Nix Flakes
+
+To use the Ruby LSP with Nix flakes, set the version manager to `nix-develop`.
+
+```jsonc
+{
+  "rubyLsp.rubyVersionManager": {
+    "identifier": "nix-develop"
+  }
+}
+```
+
+By default, this will use `nix develop --command ruby` to activate the environment. If you need to specify a path to a
+flake, you can do so with the `rubyLsp.customRubyCommand` setting.
+
+```jsonc
+{
+  "rubyLsp.rubyVersionManager": {
+    "identifier": "nix-develop"
+  },
+  "rubyLsp.customRubyCommand": "/path/to/dir/containing/flake"
+}
+```
+
+This will result in the activation command `nix develop /path/to/dir/containing/flake --command ruby`.
+
 ## Custom activation
 
 If you're using a different version manager that's not supported by this extension or if you're manually inserting the Ruby

vscode/package.json

@@ -390,6 +390,7 @@
                 "rvm",
                 "shadowenv",
                 "mise",
+                "nix-develop",
                 "custom"
               ],
               "default": "auto"

vscode/src/ruby.ts

@@ -11,6 +11,7 @@ import { VersionManager } from "./ruby/versionManager";
 import { Mise } from "./ruby/mise";
 import { RubyInstaller } from "./ruby/rubyInstaller";
 import { Rbenv } from "./ruby/rbenv";
+import { NixDevelop } from "./ruby/nixDevelop";
 import { Rvm } from "./ruby/rvm";
 import { None } from "./ruby/none";
 import { Custom } from "./ruby/custom";
@@ -44,6 +45,7 @@ export enum ManagerIdentifier {
   Shadowenv = "shadowenv",
   Mise = "mise",
   RubyInstaller = "rubyInstaller",
+  NixDevelop = "nix-develop",
   None = "none",
   Custom = "custom",
 }
@@ -318,6 +320,11 @@ export class Ruby implements RubyInterface {
           new RubyInstaller(this.workspaceFolder, this.outputChannel, this.context, this.manuallySelectRuby.bind(this)),
         );
         break;
+      case ManagerIdentifier.NixDevelop:
+        await this.runActivation(
+          new NixDevelop(this.workspaceFolder, this.outputChannel, this.context, this.manuallySelectRuby.bind(this)),
+        );
+        break;
       case ManagerIdentifier.Custom:
         await this.runActivation(
           new Custom(this.workspaceFolder, this.outputChannel, this.context, this.manuallySelectRuby.bind(this)),

vscode/src/ruby/nixDevelop.ts

@@ -0,0 +1,26 @@
+import * as vscode from "vscode";
+
+import { VersionManager, ActivationResult } from "./versionManager";
+
+export class NixDevelop extends VersionManager {
+  async activate(): Promise<ActivationResult> {
+    const customCommand = this.customCommand();
+    const command = `nix develop ${customCommand} --command ruby`;
+    const parsedResult = await this.runEnvActivationScript(command);
+
+    return {
+      env: { ...process.env, ...parsedResult.env },
+      yjit: parsedResult.yjit,
+      version: parsedResult.version,
+      gemPath: parsedResult.gemPath,
+    };
+  }
+
+  private customCommand() {
+    const configuration = vscode.workspace.getConfiguration("rubyLsp");
+    const customCommand: string | undefined =
+      configuration.get("customRubyCommand");
+
+    return customCommand || "";
+  }
+}