fix(compartment-mapper): add support for alternatives in exports defnitions

[naugtur]

There's no point in iterating the array, because in the top 1000+ packages with exports field defined as an object, all examples using an array define the same export twice in the array - once as an object with default/import alternatives and another as string.

We support both ways, so taking [0] is enough of an alternative choice algorithm.

Edit: Iterating the array now, for correctness ;)

[naugtur]

Alternative implementation that doesn't perform one unnecessary operation just feels clunky

    let sample,
      alternative,
      i = 0;
    do {
      alternative = interpretExports(name, exports[i], tags);
      sample = alternative.next();
      i++;
    } while (sample.done);

    yield sample.value;
    yield* alternative;

This is not a heavy operation, so I decided to go with spawning 2 copies of the successful generator.

[kriskowal]

It took me a moment to read, but I agree it’s better than the alternative you propose. I had imagined something like:

for (const section of exports) {
  const results = [...interpretExports(name, section, tags)];
  if (results.length > 0) {
    yield* results;
    break;
  }
}

I’m convinced that your solution is equivalent.

[naugtur]

I'll replace with this to avoid having to look at .next().done. Thanks.

[kriskowal]

✅

[kriskowal]

It took me a moment to read, but I agree it’s better than the alternative you propose. I had imagined something like:

for (const section of exports) {
  const results = [...interpretExports(name, section, tags)];
  if (results.length > 0) {
    yield* results;
    break;
  }
}

I’m convinced that your solution is equivalent.