Support react-i18next "defaults" prop

[beheh]

Version

• i18next: 11.2.2
• i18next-scanner: 2.4.6
• react-i18next: 7.7.0

Configuration

options: {
	// use strings as keys
	nsSeparator: false,
	keySeparator: false,
	// settings
	defaultNs: "frontend",
	lngs: ["en"],
	resource: {
		loadPath: "{{lng}}/{{ns}}.json",
		savePath: "{{lng}}/{{ns}}.json",
	},
	func: false,
	trans: false,
	defaultValue: (language, namespace, key) => key,
},

react-i18n v7.7.0 introduced the defaults prop (see i18next/react-i18next#439). I expect the following code:

<Trans
  defaults="Hello <0>{val}</0>!"
  tOptions={{val: "World"}}
  components=[<strong>foo</strong>]
/>

to lead to the following output:

{
  "Hello <0>{val}</0>!": "Hello <0>{val}</0>!"
}

[beheh]

It looks like this needs at least 3 things:

• add support for the defaults attribute (probably overridable like the i18nKey prop)
• add support for self-closing Trans components
• add support for <\d>s inside attributes

Especially the latter two probably mean rewriting the regular expression a bit.