ProductService functions have different default values for scope parameter

[timdk]

Describe the bug
When omitting the scope parameter to isLoading(), isSuccess() or hasError() it does not use the same scope as get()

Tell us the version of Spartacus

• Library version: 2211.19

To Reproduce
Set up an observable to fetch a non-existing product like below.

const badProductCode = '9999';
combineLatest([
  this.productService.get(badProductCode),
  this.productService.hasError(badProductCode),
]).pipe(
  filter(([product, hasError]) => Boolean(product || (!product && hasError))),
).subscribe(([product, hasError]) => {
  console.log(product, hasError);
});

This never completes despite state being updated (see screenshot below). If the filter is removed it only emits undefined, false and never logs true for hasError()

ProductService uses DEFAULT_SCOPE for get() when it's omitted but '' for the other functions.

It can be resolved by using this.productService.hasError(badProductCode, DEFAULT_SCOPE) instead, but it's not immediately obvious.

It seems hasError(productCode) will never select a valid scope unless the user has intentionally passed '' as a scope when fetching a product.

Expected behavior
I would expect that omitting scope for the status functions uses the same DEFAULT_SCOPE constant as get().

Screenshots
The loading and error states are updated under the default entity in redux.

Desktop:

• OS: All
• Browser: All
• Version: All

Additional context
Perhaps this is not a bug but more of an API quirk which could catch people out. Since '' is not a scope used or exported by ProductScope it seems unintentional.