feat: Support proto2 required messages

[tresabhi]

Eliminate x | undefined when required is passed (done)

syntax = "proto2";

message Test {
  required Child child_a = 1;
  required uint32 child_b = 2;
  optional uint32 child_c = 3;
}

message Child {
  required string name = 1;
}

...now gets transpiled into:

export interface Test {
- child_a: Child | undefined;
+ child_a: Child;
  child_b: number;
- child_c: number;
+ child_c: number | undefined;
}

export interface Child {
  value: string;
}

Update createBaseX (done)

1. Required messages will be created recursively by calling their respective createBaseX functions
2. Required primitives will be declared as normal
3. Optional primitives and messages will just be undefined

function createBaseTest(): Test {
- return { child_a: undefined, child_b: 0, child_c: 0 };
+ return { child_a: createBaseChild(), child_b: 0, child_c: undefined };
}

Make fromJSON throw an error for fields with required

1. Add assertSet which throws a TypeError if a required field is not passed
2. Optional fields just get set to undefined

Assert set:

function assertSet<T>(field: string, value: T | undefined): T {
  if (!isSet(value)) {
    throw new Error(`Required field ${field} is not set`);
  }

  return value as T;
}

Changes to from JSON:

fromJSON(object: any): Test {
  return {
-   child_a: isSet(object.child_a) ? Child.fromJSON(object.child_a) : undefined,
-   child_b: isSet(object.child_b) ? globalThis.Number(object.child_b) : 0,
+   child_a: Child.fromJSON(assertSet('Test.child_a', object.child_a)),
+   child_b: globalThis.Number(assertSet('Test.child_b', object.child_b)),
    child_c: isSet(object.child_c) ? globalThis.Number(object.child_c) : 0,
}

Update documentation (done)

[stephenh]

Hi @tresabhi , thanks for the PR!

I've only scanned it, but it lgtm so far...

Can you update the integration/proto2/proto2-optionals-test.ts test with some minimal changes (doesn't have to be very fancy) that would have not compiled/not worked before your changes, but that compile/now work with your changes?

Just to provide us with some regression tests going forward. Thanks!

[tresabhi]

This test has helped me find a few more edge cases. I'm on it already before I update the test.

Edit: I have resolved all issues that I found

Edit 2: nope, found some issues using it in my own project, back to the drawing board

Edit 3: ok everything's cool now

[tresabhi]

I implemented this experimental version onto my website: https://blitzkit.app/, which serves as a pretty good benchmark for the tech and works without a single hitch. The proto files aren't anything to be scoffed at: https://github.com/tresabhi/blitzkit/tree/dev/packages/core/src/protos.

[stephenh]

@tresabhi looks great so far! Looks like maybe more of the integration/* test need updating, if you could take a look (sorry, GitHub makes me hit Run & Approve on the PR for you to see the test runs 🤷 ). Thanks!

[tresabhi]

Stephen, just fyi, I'm working on it; it's just been slow because I have been a bit busy irl.

[stephenh]

No problem, thanks for the update!