fix: load plugins by default when VP_COMMAND is unset

When running vitest directly or via the VS Code extension, VP_COMMAND
is not set. Default to loading plugins in this case for compatibility.

Use a blocklist (NON_VITE_COMMANDS) instead of an allowlist so that
unknown or unset commands load plugins by default.

Author: fengmk2

packages/cli/src/__tests__/index.spec.ts

@@ -72,7 +72,7 @@ test.each(['dev', 'build', 'test', 'preview'])(
   },
 );
 
-test.each(['lint', 'fmt', 'check', 'pack', 'install', 'run'])(
+test.each(['lint', 'fmt', 'check', 'pack', 'install'])(
   'defineConfig skips plugins factory when VP_COMMAND is %s',
   (cmd) => {
     process.env.VP_COMMAND = cmd;
@@ -85,14 +85,13 @@ test.each(['lint', 'fmt', 'check', 'pack', 'install', 'run'])(
   },
 );
 
-test('defineConfig skips plugins factory when VP_COMMAND is unset', () => {
+test('defineConfig executes plugins factory when VP_COMMAND is unset', () => {
   delete process.env.VP_COMMAND;
-  const factoryFn = vi.fn(() => [{ name: 'should-not-load' }]);
   const config = defineConfig({
-    plugins: factoryFn,
+    plugins: () => [{ name: 'no-vp-plugin' }],
   });
-  expect(factoryFn).not.toHaveBeenCalled();
-  expect(config.plugins?.length).toBe(0);
+  expect(config.plugins?.length).toBe(1);
+  expect((config.plugins?.[0] as { name: string })?.name).toBe('no-vp-plugin');
 });
 
 test('defineConfig handles function config with plugins factory', () => {

packages/cli/src/define-config.ts

@@ -68,17 +68,21 @@ export function defineConfig(config: VPUserConfigExport): VPUserConfigExport {
   return viteDefineConfig(config as UserConfig);
 }
 
-const VITE_COMMANDS = new Set(['dev', 'build', 'test', 'preview']);
+const NON_VITE_COMMANDS = new Set(['lint', 'fmt', 'check', 'pack', 'install']);
 
-function isViteCommand(): boolean {
-  return VITE_COMMANDS.has(process.env.VP_COMMAND ?? '');
+function shouldLoadPlugins(): boolean {
+  const cmd = process.env.VP_COMMAND;
+  if (!cmd) {
+    return true;
+  }
+  return !NON_VITE_COMMANDS.has(cmd);
 }
 
 function resolvePlugins(plugins: PluginOption[] | PluginsFactory): PluginOption[] {
   if (typeof plugins !== 'function') {
     return plugins;
   }
-  if (!isViteCommand()) {
+  if (!shouldLoadPlugins()) {
     return [];
   }