How to maintain unknown/wildcard queryParams through a transition? - ember.js

Question

I have a route (route-a) that transitions to another route (route-b) and I am trying to find a way for the destination URL to maintain the all query parameters, even if route-b does not know about them in advance.
For example, if a user visits https://example.com/route-a/?var1=x&var2=y, and the transition to route-b happens like this:
afterModel(model, transition) {
this.transitionTo('route-b', model, {queryParams: transition.to.queryParams}) // transition route-a to route-b
}
...the ultimate URL will be https://example.com/route-b/ — without the query params.
Now, I realize the "Ember way" is to define the queryParams on route-b's controller in advance, but in this particular use-case, I do not know the queryParams in advance. Route B consumes any and all query params provided to it, which means they would be impossible to enumerate in advance.
How can I transition to a new route without dropping query parameters that are not specifically enumerated on the destination route's controller?
Is there a way to handle unknown queryParams, or is there the notion of a wildcard for queryParams (similar to *path routes)?

Answer 1

Update: I'm not marking this as the answer, because as jelhan notes below, using a computed property for this key is explicitly identified as a no-no in the docs. But it worked for our use-case, and it might for others, though I'm guessing it may break down if you have additional queryParams in other routes that might conflict when Ember attempts to combine them.
Previous answer:
My solution here ended up using Ember's computed method to auto-generate the Array of query params by parsing the URL.
queryParams: computed("router.location", function () {
let qp = this.get("router.location").getURL().split("?")[1];
if (qp) {
let qpAsObj = JSON.parse(
'{"' +
decodeURI(qp)
.replace(/"/g, '\\"')
.replace(/&/g, '","')
.replace(/=/g, '":"') +
'"}'
);
return Object.keys(qpAsObj)
}
})
If you don't want to subsequently maintain those query params on the page/model the next time a user re-visits that page ("sticky query params"), you will also need to remove the queryParams on the route:
resetController(controller) {
// unset all queryParams when leaving the route
controller.queryParams.forEach(v => {
controller.set(v, null)
})
}
This solution is... not ideal, but it works and we have tests written to ensure that we will catch any errors if it breaks going forward.