Simplify the type of MockActivityEnvironment.run

[TastyPi]

What was changed

Simplified the type of MockActivityEnvironment.run

Why?

Improves the type inference of the return type.

This example:

async function foo(): Promise<string> {
  return "foo";
}
const result = await new MockActivityEnvironment().run(foo);
result.startsWith("foo");

Does not currently compile with strict types because result is inferred as unknown instead of string. This change makes the type inference work correctly.

Checklist

1. Closes [Feature Request] Better type inference for MockActivityEnvironment.run #1710

2. How was this tested:

Made the change on my local machine and saw the red squiggly lines disappear.

3. Any docs updates needed?

I don't know, this is technically a breaking change if anyone is currently setting the type parameters.

[mjameswh]

Thanks!

At the moment, CI isn't passing. See my comments for hints on how to resolve these.

You may also add a test in test-mockactivityenv.rs using the exact code snippet you showed above. Basically:

test('MockActivityEnvironment return type is correctly inferred', async (t) => {
  async function foo(): Promise<string> {
    return 'foo';
  }
  const result = await new MockActivityEnvironment().run(foo);
  // There should be no compile time error on this line
  result.startsWith('foo');
  t.pass();
});

[TastyPi]

Thanks for the review @mjameswh, admittedly I just did a quick edit in GitHub's integrated editor, sorry for not doing it properly 😅

I've made the changes you suggested, and I think it's all good now. I tried running npm run test in my repo, but a lot of seemingly unrelated tests failed, I'm not sure if I just haven't got my local environment set up correctly or if that is expected.