refactor: add module not found fatal message in cli/imports (#4741)

examples/styled-vue/pages/index.vue

@@ -1,7 +1,9 @@
 <template>
   <div>
     <h1>styled-vue</h1>
-    <a href="https://github.com/egoist/styled-vue" class="github">Check it out on GitHub.</a>
+    <a href="https://github.com/egoist/styled-vue" class="github">
+      Check it out on GitHub.
+    </a>
   </div>
 </template>
 

packages/cli/src/imports.js

@@ -1,14 +1,26 @@
 import path from 'path'
+import consola from 'consola'
 
 const localNodeModules = path.resolve(process.cwd(), 'node_modules')
 
 // Prefer importing modules from local node_modules (for NPX and global bin)
 async function _import(modulePath) {
   let m
-  try {
-    m = await import(path.resolve(localNodeModules, modulePath))
-  } catch (e) {
-    m = await import(modulePath)
+  for (const mp of [ path.resolve(localNodeModules, modulePath), modulePath ]) {
+    try {
+      m = await import(mp)
+    } catch (e) {
+      if (e.code !== 'MODULE_NOT_FOUND') {
+        throw e
+      } else if (mp === modulePath) {
+        consola.fatal(
+          `Module ${modulePath} not found.\n\n`,
+          `Please install missing dependency:\n\n`,
+          `Using npm:  npm i ${modulePath}\n\n`,
+          `Using yarn: yarn add ${modulePath}`
+        )
+      }
+    }
   }
   return m
 }
@@ -17,3 +29,4 @@ export const builder = () => _import('@nuxt/builder')
 export const webpack = () => _import('@nuxt/webpack')
 export const generator = () => _import('@nuxt/generator')
 export const core = () => _import('@nuxt/core')
+export const importModule = _import

packages/cli/test/unit/imports.test.js

@@ -0,0 +1,24 @@
+import consola from 'consola'
+import { importModule } from '../../src/imports'
+
+describe('imports', () => {
+  test('should import relative module', async () => {
+    await expect(importModule('jest')).resolves.toBeDefined()
+  })
+  test('should import core module', async () => {
+    await expect(importModule('path')).resolves.toBeDefined()
+  })
+  test('should print error when module not found', async () => {
+    await expect(importModule('not-found-module')).resolves.toBeUndefined()
+    expect(consola.fatal).toHaveBeenCalled()
+    expect(consola.fatal).toHaveBeenCalledWith(
+      `Module not-found-module not found.\n\n`,
+      `Please install missing dependency:\n\n`,
+      `Using npm:  npm i not-found-module\n\n`,
+      `Using yarn: yarn add not-found-module`
+    )
+  })
+  test('should throw error when error is not module not found', async () => {
+    await expect(importModule('jest/README.md')).rejects.toThrow()
+  })
+})