feat: umi plugin list (umijs#157)

* support command:plugin

* bugfix:presets未定义时,UMI_PRESETS为undefined

* code formatting

* filter plugin.ts

* pnpm format

examples/boilerplate/package.json

@@ -1,6 +1,10 @@
 {
   "scripts": {
-    "dev": "../../packages/umi/bin/umi.js dev"
+    "start": "pnpm run dev",
+    "dev": "umi dev",
+    "plugin": "umi plugin"
   },
-  "devDependencies": {}
+  "devDependencies": {
+    "umi": "workspace:*"
+  }
 }

packages/preset-built-in/src/commands/plugin.ts

@@ -0,0 +1,33 @@
+import { IApi } from '../types';
+
+export default (api: IApi) => {
+  api.registerCommand({
+    name: 'plugin',
+    description: 'inspect umi plugins',
+    fn({ args }) {
+      const command = args._[0];
+      console.log('command', command);
+
+      if (!command) {
+        throw new Error(`
+Sub command not found: umi plugin
+Did you mean:
+  umi plugin list
+        `);
+      }
+      switch (command) {
+        case 'list':
+          getPluginList();
+          break;
+        default:
+          throw new Error(`Unsupported sub command ${command} for umi plugin.`);
+      }
+      function getPluginList() {
+        Object.keys(api.service.plugins).forEach((pluginId: string) => {
+          const plugin = api.service.plugins[pluginId];
+          console.info(`- ${plugin.id}`);
+        });
+      }
+    },
+  });
+};

packages/preset-built-in/src/index.ts

@@ -19,6 +19,7 @@ export default () => {
       require.resolve('./commands/setup'),
       require.resolve('./commands/version'),
       require.resolve('./commands/generate/generate'),
+      require.resolve('./commands/plugin'),
     ],
   };
 };