node-loader: add support showing messages

Author: wooorm

package-lock.json

@@ -20,6 +20,7 @@ import fs from 'node:fs/promises'
 import {createFormatAwareProcessors} from '@mdx-js/mdx/internal-create-format-aware-processors'
 import {extnamesToRegex} from '@mdx-js/mdx/internal-extnames-to-regex'
 import {SourceMapGenerator} from 'source-map'
+import {reporter} from 'vfile-reporter'
 import {VFile} from 'vfile'
 import {development as defaultDevelopment} from '#condition'
 
@@ -62,6 +63,11 @@ export function createLoader(options) {
       const value = await fs.readFile(url)
       const file = await process(new VFile({value, path: url}))
 
+      /* c8 ignore next 3 -- hard to test. */
+      if (file.messages.length > 0) {
+        console.error(reporter(file))
+      }
+
       return {
         format: 'module',
         shortCircuit: true,

packages/node-loader/lib/index.js

@@ -45,6 +45,7 @@
   "dependencies": {
     "@mdx-js/mdx": "^3.0.0",
     "source-map": "^0.7.0",
+    "vfile-reporter": "^8.0.0",
     "vfile": "^6.0.0"
   },
   "devDependencies": {},