Use env shebangs for RubyGems installs

lib/ruby_lsp/setup_bundler.rb

@@ -445,7 +445,7 @@ def install_bundler_if_needed
       requirement = Gem::Requirement.new(@bundler_version.to_s)
       return if Gem::Specification.any? { |s| s.name == "bundler" && requirement =~ s.version }
 
-      Gem.install("bundler", @bundler_version.to_s)
+      Gem.install("bundler", @bundler_version.to_s, env_shebang: true)
     end
 
     #: -> bool

test/setup_bundler_test.rb

@@ -655,6 +655,38 @@ def test_sets_bundler_version_to_avoid_reloads
     end
   end
 
+  def test_installs_missing_bundler_with_env_shebang
+    in_temp_dir do |dir|
+      File.write(File.join(dir, "Gemfile"), <<~GEMFILE)
+        source "https://rubygems.org"
+      GEMFILE
+
+      File.write(File.join(dir, "Gemfile.lock"), <<~LOCKFILE)
+        GEM
+          remote: https://rubygems.org/
+          specs:
+
+        PLATFORMS
+          ruby
+
+        DEPENDENCIES
+
+        BUNDLED WITH
+          999.999.999
+      LOCKFILE
+
+      capture_subprocess_io do
+        Bundler.with_unbundled_env do
+          compose = RubyLsp::SetupBundler.new(dir, launcher: true)
+          compose.expects(:run_bundle_install_directly)
+          Gem.expects(:install).with("bundler", "999.999.999", env_shebang: true)
+
+          compose.setup!
+        end
+      end
+    end
+  end
+
   def test_invoke_cli_calls_bundler_directly_for_install
     in_temp_dir do |dir|
       File.write(File.join(dir, "gems.rb"), <<~GEMFILE)

vscode/src/test/suite/workspace.test.ts

@@ -8,9 +8,10 @@ import * as vscode from "vscode";
 import { beforeEach, afterEach } from "mocha";
 
 import { Workspace } from "../../workspace";
+import * as common from "../../common";
 
 import { FAKE_TELEMETRY } from "./fakeTelemetry";
-import { createContext, FakeContext } from "./helpers";
+import { createContext, FakeContext, stubWorkspaceConfiguration } from "./helpers";
 
 suite("Workspace", () => {
   let workspacePath: string;
@@ -41,6 +42,50 @@ suite("Workspace", () => {
     context.dispose();
   });
 
+  test("installs ruby-lsp with env shebang", async () => {
+    stubWorkspaceConfiguration(sandbox, { rubyLsp: { bundleGemfile: "" } });
+    sandbox.stub(common, "featureEnabled").returns(false);
+
+    const execStub = sandbox.stub(common, "asyncExec");
+    execStub.onFirstCall().resolves({ stdout: "", stderr: "" });
+    execStub.onSecondCall().resolves({ stdout: "", stderr: "" });
+
+    await workspace.installOrUpdateServer(false);
+
+    assert.strictEqual(execStub.firstCall.args[0], "gem list ruby-lsp language_server-protocol prism rbs");
+    assert.strictEqual(execStub.secondCall.args[0], "gem install ruby-lsp --env-shebang");
+  });
+
+  test("updates ruby-lsp with env shebang", async () => {
+    stubWorkspaceConfiguration(sandbox, { rubyLsp: { bundleGemfile: "" } });
+    sandbox.stub(common, "featureEnabled").returns(false);
+
+    const execStub = sandbox.stub(common, "asyncExec");
+    execStub.onFirstCall().resolves({
+      stdout: "ruby-lsp (0.1.0)\nlanguage_server-protocol (3.17.0)\nprism (1.2.0)\nrbs (3.0.0)\n",
+      stderr: "",
+    });
+    execStub.onSecondCall().resolves({ stdout: "", stderr: "" });
+
+    await workspace.installOrUpdateServer(false);
+
+    assert.strictEqual(execStub.firstCall.args[0], "gem list ruby-lsp language_server-protocol prism rbs");
+    assert.strictEqual(execStub.secondCall.args[0], "gem update ruby-lsp --env-shebang");
+  });
+
+  test("installs beta ruby-lsp with prerelease and env shebang flags", async () => {
+    stubWorkspaceConfiguration(sandbox, { rubyLsp: { bundleGemfile: "" } });
+    sandbox.stub(common, "featureEnabled").returns(true);
+
+    const execStub = sandbox.stub(common, "asyncExec");
+    execStub.onFirstCall().resolves({ stdout: "", stderr: "" });
+    execStub.onSecondCall().resolves({ stdout: "", stderr: "" });
+
+    await workspace.installOrUpdateServer(false);
+
+    assert.strictEqual(execStub.secondCall.args[0], "gem install ruby-lsp --pre --env-shebang");
+  });
+
   test("repeated rebase steps don't trigger multiple restarts", async () => {
     const gitDir = path.join(workspacePath, ".git");
     fs.mkdirSync(gitDir);

vscode/src/workspace.ts

@@ -241,8 +241,8 @@ export class Workspace implements WorkspaceInterface {
     await this.lspClient?.dispose();
   }
 
-  // Install or update the `ruby-lsp` gem globally with `gem install ruby-lsp` or `gem update ruby-lsp`. We only try to
-  // update on a daily basis, not every time the server boots
+  // Install or update the `ruby-lsp` gem globally with `gem install ruby-lsp --env-shebang` or
+  // `gem update ruby-lsp --env-shebang`. We only try to update on a daily basis, not every time the server boots
   async installOrUpdateServer(manualInvocation: boolean): Promise<void> {
     // If there's a user configured custom bundle to run the LSP, then we do not perform auto-updates and let the user
     // manage that custom bundle themselves
@@ -264,12 +264,13 @@ export class Workspace implements WorkspaceInterface {
     });
 
     const preFlag = featureEnabled("betaServer") ? " --pre" : "";
+    const gemFlags = `${preFlag} --env-shebang`;
 
     // If any of the Ruby LSP's dependencies are missing, we need to install them. For example, if the user runs `gem
     // uninstall prism`, then we must ensure it's installed or else rubygems will fail when trying to launch the
     // executable
     if (!dependencies.every((dep) => new RegExp(`${dep}\\s`).exec(stdout))) {
-      await asyncExec(`gem install ruby-lsp${preFlag}`, {
+      await asyncExec(`gem install ruby-lsp${gemFlags}`, {
         cwd: this.workspaceFolder.uri.fsPath,
         env: this.ruby.env,
       });
@@ -295,7 +296,7 @@ export class Workspace implements WorkspaceInterface {
     // If we haven't updated the gem in the last 24 hours or if the user manually asked for an update, update it
     if (manualInvocation || lastUpdatedAt === undefined || Date.now() - lastUpdatedAt > oneDayInMs) {
       try {
-        await asyncExec(`gem update ruby-lsp${preFlag}`, {
+        await asyncExec(`gem update ruby-lsp${gemFlags}`, {
           cwd: this.workspaceFolder.uri.fsPath,
           env: this.ruby.env,
         });