fix: don't do browser language detection during Nuxt generate (#718)

During generate there is no point in guessing the browser language
as it's not the target's user language anyway.

Co-authored-by: Rafal Chlodnicki

src/templates/plugin.main.js

@@ -126,6 +126,11 @@ export default async (context) => {
   }
 
   const doDetectBrowserLanguage = () => {
+    // Browser detection is ignored if it is a nuxt generate.
+    if (process.static && process.server) {
+      return false
+    }
+
     const { alwaysRedirect, fallbackLocale } = detectBrowserLanguage
 
     let matchedLocale

test/browser.test.js

@@ -185,6 +185,59 @@ describe(`${browserString} (generate)`, () => {
   })
 })
 
+describe(`${browserString} (generate with detectBrowserLanguage.fallbackLocale)`, () => {
+  let browser
+  let page
+  let port
+  // Local method that overrides imported one.
+  let url
+
+  beforeAll(async () => {
+    const distDir = resolve(__dirname, 'fixture', 'basic', '.nuxt-generate')
+
+    const overrides = {
+      generate: { dir: distDir },
+      i18n: {
+        detectBrowserLanguage: {
+          fallbackLocale: 'en'
+        }
+      }
+    }
+
+    await generate(loadConfig(__dirname, 'basic', overrides, { merge: true }))
+
+    port = await getPort()
+    url = path => `http://localhost:${port}${path}`
+
+    browser = await createBrowser(browserString, {
+      folder: distDir,
+      staticServer: {
+        folder: distDir,
+        port
+      },
+      extendPage (page) {
+        return {
+          navigate: createNavigator(page)
+        }
+      }
+    })
+  })
+
+  afterAll(async () => {
+    if (browser) {
+      await browser.close()
+    }
+  })
+
+  test('generates pages in all locales', async () => {
+    page = await browser.page(url('/'))
+    expect(await page.getText('body')).toContain('locale: en')
+
+    await page.navigate('/fr')
+    expect(await page.getText('body')).toContain('locale: fr')
+  })
+})
+
 describe(`${browserString} (no fallbackLocale, browser language not supported)`, () => {
   let nuxt
   let browser

test/module.test.js

@@ -1,4 +1,6 @@
-import { setup, loadConfig, get, url } from '@nuxtjs/module-test-utils'
+import { resolve } from 'path'
+import { readFileSync } from 'fs'
+import { generate, setup, loadConfig, get, url } from '@nuxtjs/module-test-utils'
 import { JSDOM } from 'jsdom'
 
 import { getSeoTags } from './utils'
@@ -1166,3 +1168,35 @@ describe('prefix + detectBrowserLanguage + alwaysRedirect', () => {
     expect(dom.querySelector('#current-locale').textContent).toBe('locale: fr')
   })
 })
+
+describe('generate with detectBrowserLanguage.fallbackLocale', () => {
+  const distDir = resolve(__dirname, 'fixture', 'basic', '.nuxt-generate')
+
+  beforeAll(async () => {
+    const overrides = {
+      generate: { dir: distDir },
+      i18n: {
+        detectBrowserLanguage: {
+          fallbackLocale: 'en'
+        }
+      }
+    }
+
+    await generate(loadConfig(__dirname, 'basic', overrides, { merge: true }))
+  })
+
+  test('pre-renders all locales', () => {
+    let dom
+    let contents
+
+    contents = readFileSync(resolve(distDir, 'index.html'), 'utf-8')
+    dom = getDom(contents)
+    expect(dom.querySelector('#current-page')).toBeDefined()
+    expect(dom.querySelector('#current-page').textContent).toBe('page: Homepage')
+
+    contents = readFileSync(resolve(distDir, 'fr/index.html'), 'utf-8')
+    dom = getDom(contents)
+    expect(dom.querySelector('#current-page')).toBeDefined()
+    expect(dom.querySelector('#current-page').textContent).toBe('page: Accueil')
+  })
+})