fix: cli-i18n fallbacks

packages/uni-cli-i18n/__tests__/env.spec.js

 describe('env', () => {
   it('CLI', () => {
-    process.env.LANG = 'fr'
-    const i18n = require('../lib/index')
-    expect(i18n.getLocale()).toBe('fr')
+    process.env.LANG = 'es'
+    const { getLocale } = require('../lib/locale')
+    expect(getLocale()).toBe('es')
   })
   it('HBuilderX', () => {
     process.env.UNI_HBUILDERX_LANGID = 'fr'
-    const i18n = require('../lib/index')
-    expect(i18n.getLocale()).toBe('fr')
+    const { getLocale } = require('../lib/locale')
+    expect(getLocale()).toBe('fr')
   })
 })

packages/uni-cli-i18n/__tests__/locales.spec.js

+
+
+describe('locales', () => {
+  it('default', () => {
+    const i18n = require('../lib/index')
+    expect(i18n.setLocale('fr')).toBe('en')
+  })
+  it('fallbacks', () => {
+    const i18n = require('../lib/index')
+    expect(i18n.setLocale('zh')).toBe('zh_CN')
+    expect(i18n.setLocale('zh_SG')).toBe('zh_CN')
+  })
+})
\ No newline at end of file

packages/uni-cli-i18n/lib/index.js

 const { I18n } = require('i18n')
-const { osLocale } = require('os-locale-s/cjs')
-const { format } = require('./lang')
+const { getLocale } = require('./locale')
 
-const defaultLocale = format(process.env.UNI_HBUILDERX_LANGID || osLocale.sync({ spawn: false, cache: false }) || 'en')
+const defaultLocale = 'en'
+
+const locale = getLocale()
 
 const i18n = new I18n()
 
@@ -24,7 +25,15 @@ locales.forEach(item => {
 
 i18n.configure({
   staticCatalog,
-  defaultLocale
+  defaultLocale,
+  retryInDefaultLocale: true,
+  fallbacks: {
+    'en_*': 'en',
+    'zh': 'zh_CN',
+    'zh_*': 'zh_CN',
+  }
 })
 
+i18n.setLocale(locale)
+
 module.exports = i18n

packages/uni-cli-i18n/lib/locale.js

+const { format } = require('./lang')
+const { osLocale } = require('os-locale-s/cjs')
+
+function getLocale () {
+  return format(process.env.UNI_HBUILDERX_LANGID || osLocale.sync({ spawn: false, cache: false }) || defaultLocale)
+}
+
+module.exports = {
+  getLocale
+}