fix: no false positives for plugins with index.js (#4714)

resolves #4713 [release]

packages/builder/src/builder.js

@@ -27,7 +27,8 @@ import {
   serializeFunction,
   determineGlobals,
   stripWhitespace,
-  isString
+  isString,
+  isIndexFileAndFolder
 } from '@nuxt/utils'
 
 import BuildContext from './context'
@@ -139,7 +140,9 @@ export default class Builder {
 
       if (!pluginFiles || pluginFiles.length === 0) {
         throw new Error(`Plugin not found: ${p.src}`)
-      } else if (pluginFiles.length > 1) {
+      }
+
+      if (pluginFiles.length > 1 && !isIndexFileAndFolder(pluginFiles)) {
         consola.warn({
           message: `Found ${pluginFiles.length} plugins that match the configuration, suggest to specify extension:`,
           additional: '\n' + pluginFiles.map(x => `- ${x}`).join('\n')

packages/utils/src/resolve.js

@@ -98,3 +98,13 @@ export function defineAlias(src, target, prop, opts = {}) {
     }
   })
 }
+
+const isIndex = s => /(.*)\/index\.[^/]+$/.test(s)
+
+export function isIndexFileAndFolder(pluginFiles) {
+  // Return early in case the matching file count exceeds 2 (index.js + folder)
+  if (pluginFiles.length !== 2) {
+    return false
+  }
+  return pluginFiles.some(isIndex)
+}

test/fixtures/with-config/nuxt.config.js

@@ -37,6 +37,7 @@ export default {
   extensions: 'ts',
   plugins: [
     '~/plugins/test',
+    '~/plugins/doubled',
     { src: '~/plugins/test.plugin', mode: 'abc' },
     '~/plugins/test.client',
     '~/plugins/test.server',

test/fixtures/with-config/plugins/doubled/index.js

@@ -0,0 +1 @@
+export default () => {}