fix: modern=true or false not work as expected (#4378)

packages/cli/src/commands/generate.js

@@ -1,5 +1,6 @@
 import consola from 'consola'
 import { common } from '../options'
+import { normalizeArg } from '../utils'
 
 export default {
   name: 'generate',
@@ -28,7 +29,7 @@ export default {
       ...common.modern,
       description: 'Generate app in modern build (modern mode can be only client)',
       prepare(cmd, options, argv) {
-        if (argv.modern !== undefined) {
+        if (normalizeArg(argv.modern)) {
           options.modern = 'client'
         }
       }

packages/cli/src/options/common.js

@@ -1,3 +1,5 @@
+import { normalizeArg } from '../utils'
+
 export default {
   spa: {
     alias: 's',
@@ -21,7 +23,7 @@ export default {
     description: 'Build/Start app for modern browsers, e.g. server, client and false',
     prepare(cmd, options, argv) {
       if (argv.modern !== undefined) {
-        options.modern = argv.modern || true
+        options.modern = normalizeArg(argv.modern)
       }
     }
   },

packages/cli/src/utils/index.js

@@ -110,3 +110,21 @@ export function showBanner(nuxt) {
 
   process.stdout.write(box + '\n')
 }
+
+/**
+ * Normalize string argument in command
+ *
+ * @export
+ * @param {String} argument
+ * @param {*} defaultValue
+ * @returns formatted argument
+ */
+export function normalizeArg(arg, defaultValue) {
+  switch (arg) {
+    case 'true': arg = true; break
+    case '': arg = true; break
+    case 'false': arg = false; break
+    case undefined: arg = defaultValue; break
+  }
+  return arg
+}

packages/cli/test/unit/build.test.js

@@ -63,6 +63,22 @@ describe('build', () => {
     expect(builder).toHaveBeenCalled()
   })
 
+  test('build with modern mode', async () => {
+    mockGetNuxt({
+      mode: 'universal'
+    })
+    mockGetBuilder(Promise.resolve())
+
+    const cmd = NuxtCommand.from(build)
+    const args = ['build', '.', '--m']
+
+    const options = await cmd.getNuxtConfig(cmd.getArgv(args))
+
+    await cmd.run()
+
+    expect(options.modern).toBe(true)
+  })
+
   test('catches error', async () => {
     mockGetNuxt({ mode: 'universal' })
     mockGetBuilder(Promise.reject(new Error('Builder Error')))

packages/cli/test/unit/generate.test.js

@@ -64,6 +64,20 @@ describe('generate', () => {
     expect(generator.mock.calls[0][0].build).toBe(true)
   })
 
+  test('generate with modern mode', async () => {
+    mockGetNuxt()
+    mockGetGenerator(Promise.resolve())
+
+    const cmd = NuxtCommand.from(generate)
+    const args = ['generate', '.', '--m']
+
+    const options = await cmd.getNuxtConfig(cmd.getArgv(args))
+
+    await cmd.run()
+
+    expect(options.modern).toBe('client')
+  })
+
   test('catches error', async () => {
     mockGetNuxt()
     mockGetGenerator(Promise.reject(new Error('Generator Error')))

packages/cli/test/unit/utils.test.js

@@ -81,6 +81,16 @@ describe('cli/utils', () => {
     expect(consola.fatal).toHaveBeenCalledWith('Error while fetching async configuration')
   })
 
+  test('normalizeArg: normalize string argument in command', () => {
+    expect(utils.normalizeArg('true')).toBe(true)
+    expect(utils.normalizeArg('false')).toBe(false)
+    expect(utils.normalizeArg(true)).toBe(true)
+    expect(utils.normalizeArg(false)).toBe(false)
+    expect(utils.normalizeArg('')).toBe(true)
+    expect(utils.normalizeArg(undefined, 'default')).toBe('default')
+    expect(utils.normalizeArg('text')).toBe('text')
+  })
+
   test('nuxtServerConfig: server env', () => {
     const options = getDefaultNuxtConfig({
       env: {