Build errors with intl-messageformat

When building my Svelte app, I’m getting these errors from svelte-i8n (and it’s dependencies.) One thing I noticed is that the intel-messageformat project is archived. Perhaps, it’s obsolete and needs to be replaced?

yarn run v1.21.1
warning package.json: No license field
$ rollup -c

src/main.js → public/bundle.js...
(!) `this` has been rewritten to `undefined`
https://rollupjs.org/guide/en/#error-this-is-undefined
node_modules/intl-messageformat/lib/core.js
4: See the accompanying LICENSE file for terms.
5: */
6: var __assign = (this && this.__assign) || function () {
                   ^
7:     __assign = Object.assign || function(t) {
8:         for (var s, i = 1, n = arguments.length; i < n; i++) {
...and 1 other occurrence
node_modules/intl-messageformat/lib/formatters.js
1: var __extends = (this && this.__extends) || (function () {
                    ^
2:     var extendStatics = function (d, b) {
3:         extendStatics = Object.setPrototypeOf ||
...and 3 other occurrences
node_modules/intl-format-cache/lib/index.js
4: See the accompanying LICENSE file for terms.
5: */
6: var __spreadArrays = (this && this.__spreadArrays) || function () {
                         ^
7:     for (var s = 0, i = 0, il = arguments.length; i < il; i++) s += arguments[i].length;
8:     for (var r = Array(s), k = 0, i = 0; i < il; i++)
...and 1 other occurrence

...and 3 other files

[attilam]

@attilam where do you add this code?

This was a while ago, but the code goes into rollup.config.js. So declare the onwarn function, and use it in export default as needed.

In my case it looked something like this:

// imports blah...

const onwarn = (warning, onwarn) => {
	// ignores the annoying this is undefined warning
	if (warning.code === 'THIS_IS_UNDEFINED') {
		return
	}

	onwarn(warning)
}

export default {
  input: ...,
  output: ...,
  onwarn, // <- added here
  plugins: ...
}

function serve() {
  ...
}

[kaisermann]

@rlaferla Hey 👋 Please check the FAQ section of the wiki https://github.com/kaisermann/svelte-i18n/wiki/FAQ#this-keyword-is-equivalent-to-undefined 😁