Allow for falsey default values (#1021)

Co-authored-by: zsunderland <[email protected]>

__tests__/useTranslation.test.js

@@ -1185,7 +1185,7 @@ describe('useTranslation', () => {
  { count: 3 },
  {
  default: {
- example: 'This is a default translation with a count: {{count}}'
+ example: 'This is a default translation with a count: {{count}}',
  },
  returnObjects: true,
  fallback: 'ns:no-translation2',
@@ -1210,9 +1210,7 @@ describe('useTranslation', () => {
  'ns:no-translation',
  { count: 3 },
  {
- default: [
- 'This is a default translation with a count: {{count}}'
- ],
+ default: ['This is a default translation with a count: {{count}}'],
  returnObjects: true,
  fallback: 'ns:no-translation2',
  }
@@ -1222,6 +1220,30 @@ describe('useTranslation', () => {
 
  const expected = 'This is a default translation with a count: 3'
 
+ const { container } = render(
+ <I18nProvider lang="en" namespaces={{}}>
+ <Inner />
+ </I18nProvider>
+ )
+ expect(container.textContent).toBe(expected)
+ })
+ test('should return falsey default values', () => {
+ const Inner = () => {
+ const { t } = useTranslation()
+ const text = t(
+ 'ns:no-translation',
+ { count: 3 },
+ {
+ default: undefined,
+ returnObjects: true,
+ fallback: 'ns:no-translation2',
+ }
+ )
+ return <>{`${text}`}</>
+ }
+
+ const expected = 'undefined'
+
  const { container } = render(
  <I18nProvider lang="en" namespaces={{}}>
  <Inner />

src/transCore.tsx

@@ -99,8 +99,17 @@ export default function transCore({
  }
  }
 
- if (empty && options?.default && !fallbacks?.length) {
- return interpolateUnknown(options.default, query)
+ if (
+ empty &&
+ options &&
+ // options.default could be a nullish value so check that the property exists
+ options.hasOwnProperty('default') &&
+ !fallbacks?.length
+ ) {
+ // if options.default is falsey there's no reason to do interpolation
+ return options.default
+ ? interpolateUnknown(options.default, query)
+ : options.default
  }
 
  // no need to try interpolation