Make RequestDetailsResolver public

[milanboers]

📜 Description

Follow up to #4323

This makes RequestDetailsResolver public and adds a constructor which just takes the a DSN and client name.

💡 Motivation and Context

ITransportFactory.create currently receives a RequestDetails. This means that, when creating a custom transport, you can't change the request details (dsn, auth header, ..) without resorting to ugly rewrites on the url / headers.

Having a public RequestDetailsResolver makes it easy to make a new instance with the desired DSN / client name.

Use case (from #4323) is to make a transport that can send to multiple different DSNs. (Somewhat simplified) example usage for that:

record MultiplexedTransportFactory(List<String> dsns) implements ITransportFactory {
  @Override
  public ITransport create(final SentryOptions options, final RequestDetails requestDetails) {
    final var transports = dsns.stream()
        .map(dsn -> new RequestDetailsResolver(dsn, options.getSentryClientName()).resolve())
        .map(newRequestDetails -> new AsyncHttpTransportFactory().create(options, newRequestDetails))
        .toList();
    return new ITransport() {
      @Override
      public void send(SentryEnvelope envelope, Hint hint) throws IOException {
        for (ITransport transport : transports) {
          transport.send(envelope, hint);
        }
      }

      @Override
      public boolean isHealthy() {
        return transports.stream().allMatch(ITransport::isHealthy);
      }

      @Override
      public void flush(long timeoutMillis) {
        transports.forEach(transport -> transport.flush(timeoutMillis));
      }

      @Override
      public RateLimiter getRateLimiter() {
        return null;
      }

      @Override
      public void close(boolean isRestarting) throws IOException {
        for (ITransport transport : transports) {
          transport.close(isRestarting);
        }
      }

      @Override
      public void close() throws IOException {
        for (ITransport transport : transports) {
          transport.close();
        }
      }
    };
  }
}

💚 How did you test it?

📝 Checklist

• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

[lcian]

Thanks @milanboers.
Yeah in theory you could do this by using a fake SentryOptions but I think it's better to have a new constructor.
You could also circumvent the fact that the class is not public by defining your custom transport class in the io.sentry package.
I'll check with the team if we want to make this a public API or not.

[lcian]

The call to RequestDetailsResolver.resolve() will now happen just a line below the original call in SentryClient, so there is nothing to worry about regarding behavioral changes.

[adinauer]

LGTM! Thanks for taking care of this.