Incorrect definite assertion for Query

[Honga1]

fluff

Hi :D. I'm exercising the library pretty well at the moment. Well done on it. So far I've only ran into type issues with things like twice extending the Facet class, which wouldn't then carry props into the react component.

Line causing type error

react-ecs/libs/core/src/lib/Query.ts

Line 20 in d06850b

const component = entity.get(t)!;

How I found this

Regarding the line above:
If I have a query

// Note 'hasAny'
const query = useQuery((entity) => entity.hasAny(FacetA, FacetB))

Then follow up with a loop:

query.loop([FacetA, FacetB], (entity, [facetA, facetB]) => {
  assert(facetA !== undefined)
  assert(facetB !== undefined)
}

Would likely throw if I only added one of the two facets FacetA FacetB. Even though they are definitely asserted on your get(t)! part.

Indeed I can reproduce this here:
https://codesandbox.io/s/zealous-nobel-q5id3?file=/src/App.tsx

Suggested fixes

One of:

• Remove the ! on the get statement
• Make query.loop filter for components given in first parameter
• Make returned tuple | undefined