How to avoid "`this` has been rewritten to `undefined`" warning when bundling Scala.js file with rollup? - rollup

Question

I'm using a Scala.js file with ECMAScript modules inside a Svelte project. When building the project with rollup I get the warning
this has been rewritten to undefined
With pointing at last line of code here
var $linkingInfo = Object.freeze({
"esVersion": 6,
"assumingES6": true,
"productionMode": true,
"linkerVersion": "1.7.1",
"fileLevelThis": this
});
and linking to this section of the documentation
Error: "this is undefined"
In a JavaScript module, this is undefined at the top level (i.e., outside functions). Because of that, Rollup will rewrite any this references to undefined so that the resulting behaviour matches what will happen when modules are natively supported.
There are occasional valid reasons for this to mean something else. If you're getting errors in your bundle, you can use options.context and options.moduleContext to change this behaviour.
In the context section I find
By default, the context of a module – i.e., the value of this at the top level – is undefined. In rare cases you might need to change this to something else, like 'window'.
Is changing the context from this to window the right thing to do in this case?
And how exactly do I add the option to rollup?
The documentation gives this info CLI: --context <contextVariable>, When adding the option like this the error persists:
[package.json]
"scripts": {
"build": "rollup -c --context window",
"dev": "rollup -c -w --context window"
...
}
When adding this line to the rollup.config file
export default {
input: ...,
output: {...},
plugins: [...],
watch: {...},
context: "window"
};
the warning vanishes - is this the right thing to do?