test(editor): fix test setup (#13929)

The tests are always passing, because we are not generating them:
https://github.com/oxc-project/oxc/actions/runs/17858412366/job/50782751216?pr=13700

introduced in #13737

Author: Sysix

editors/vscode/package.json

@@ -196,7 +196,7 @@
     "install-extension": "code --install-extension oxc_language_server.vsix --force",
     "server:build:debug": "cross-env CARGO_TARGET_DIR=./target cargo build -p oxc_language_server",
     "server:build:release": "cross-env CARGO_TARGET_DIR=./target cargo build -p oxc_language_server --release",
-    "test": "pnpm run compile && vscode-test",
+    "test": "cross-env TEST=true pnpm run compile && vscode-test",
     "type-check": "tsc --noEmit"
   },
   "devDependencies": {

editors/vscode/rolldown.config.ts

@@ -1,14 +1,26 @@
-import { defineConfig } from 'rolldown';
+import { defineConfig, type RolldownOptions } from 'rolldown';
+import { globSync } from 'tinyglobby';
+
+const input: RolldownOptions['input'] = process.env.TEST === 'true'
+  ? globSync('tests/**/*.ts')
+  : ['client/extension.ts'];
+
+const output: RolldownOptions['output'] = {
+  sourcemap: true,
+  format: 'cjs',
+  banner: `"use strict";\n`,
+  minify: true,
+};
+
+if (process.env.TEST === 'true') {
+  output.dir = 'out';
+} else {
+  output.file = 'out/main.js';
+}
 
 export default defineConfig({
-  input: 'client/extension.ts',
-  output: {
-    file: 'out/main.js',
-    sourcemap: true,
-    format: 'cjs',
-    banner: `"use strict";\n`,
-    minify: true,
-  },
+  input,
+  output,
   external: ['vscode'],
   platform: 'node',
   transform: {