feat!: remove context from NoteEmission methods

[nventuro]

In discussing how to improve developer experience by getting rid of the context object as much as possible, I realized some of it is quite low hanging fruit. We can take a similar approach to the storage object and have the aztec-nr intermediate structs keep references to the context, resulting in the end-user invoking methods that already reference the context instead of having to manually provide it. The diff speaks for itself.

Closes https://linear.app/aztec-labs/issue/F-109/remove-context-when-delivering-messages.

[benesjan]

Extremely nice change 🤩

Nico very smort

[nventuro]

It turns out returning references (or structs holding references) from an if expression is not allowed. Now that NoteEmission contains such a reference, we run into the following:

error: Cannot return a reference type from an if or match expression
    ┌─ src/state_vars/private_mutable.nr:358:9
    │  
358 │ ╭         if !is_initialized {
359 │ │             self.initialize(init_note)
360 │ │         } else {
361 │ │             self.replace(transform_fn)
362 │ │         }

To address that, I created an internal auxiliary NoteEmissionNoContext type that can be created by calling strip_context, and have the context then re-attached via attach_context. The above snippet now reads

if !is_initialized {
    self.initialize(init_note).strip_context()
} else {
    self.replace(transform_fn).strip_context()
}
    .attach_context(self.context)

This is fine to do because the context in self is the same one as in the emissions in both branches (because it is a singleton).

[nventuro]

I updated OuterNoteEmission to avoid the problematic mut ref on a return expression. The result is a bit nasty, but I want to get this out now - once we do a pass over NoteEmission and that API we'll also address Outer, its naming and how it's created, fixing this.

[AztecBot]

Flakey Tests

🤖 says: This CI run detected 1 tests that failed, but were tolerated due to a .test_patterns.yml entry.

\033[38;2;188;109;208mFLAKED\033[0m (\033[38;2;250;217;121m8;;http://ci.aztec-labs.com/e26f98c6edcaf46a�e26f98c6edcaf46a8;;�\033[0m): BOX=vanilla BROWSER=* run_compose_test vanilla-all-browsers box boxes (457s) (code: 1) (\033[38;2;188;109;208mAztec Bot\033[0m: feat!: remove context from NoteEmission methods (#17024))