feat(sdk): Add AssemblyScript SDK

[FranklinWaller]

Motivation

Adding this allows developers to develop data requests using AssemblyScript

Explanation of Changes

• Add AssemblyScript functions (http & process)
• Add integration tests

Testing

npm test

Related PRs and Issues

closes #2

[Thomasvdam]

This feels like a good candidate for some unit tests?

[Thomasvdam]

This still bothers me 😛

Quick doodle I came up with:

type FromBuffer<T> = (buffer: Uint8Array) => T;

export class PromiseStatus<F, R> {
  private constructor(
    public fulfilled: F | null,
    public rejected: R | null
  ) {}

  isFulfilled(): this is true {
    return this.fulfilled !== null;
  }

  isRejected() {
    return this.rejected !== null;
  }

  static fromStr<F, R>(promiseStatus: string, fulfilled: FromBuffer<F>, rejected: FromBuffer<R>): PromiseStatus<F, R> {
    const value = JSON.parse(promiseStatus);
    let fulfilledResult: F | null = null;
    let rejectedResult: R | null = null;

    const rawFulfilled = value.getArr('Fulfilled');
    if (rawFulfilled) {
      fulfilledResult = fulfilled(rawFulfilled);
    }

    const rawRejected = value.getArr('Rejected');
    if (rawRejected) {
      rejectedResult = rejected(rawRejected);
    }

    return new PromiseStatus(fulfilledResult, rejectedResult);
  }
}

class HTTPResponseSuccess {
  public readonly success = true;
  constructor(public buffer: Uint8Array) {};
}

class HTTPResponseFailure {
  public readonly failure = true;
  constructor(public buffer: Uint8Array) {};
}

function newSuccess(buffer: Uint8Array) {
  return new HTTPResponseSuccess(buffer);
}

function newFailure(buffer: Uint8Array) {
  return new HTTPResponseFailure(buffer);
}

const promiseStatus = PromiseStatus.fromStr('a', newSuccess, newFailure);

if (promiseStatus.isFulfilled()) {
  promiseStatus.fulfilled?.success;
} else {
  promiseStatus.rejected?.failure;
}

The main thing I still dislike is that the isFulfilled check still doesn't let TS infer that the property is not null.

Not saying this is the way to go but hopefully this triggers some new ideas on how to improve this.

[Thomasvdam]

Also don't mind the implementation in fromStr, I made a few edits so my editor would shut up.

[FranklinWaller]

To be honest we can just ditch the isFulfilled and isRejected, i'm also not really using them.

[Thomasvdam]

The remaining open comments are more (really) nice to haves.