Stub does not list files if prefix is a directory

[hbibel]

Hi all,

I found an inconsistency between the stub and the live implementations of the s3 service with regards to listing objects with a prefix. This small app highlights the issue:

package zio.s3

import zio._
import zio.s3._
import software.amazon.awssdk.regions.Region
import software.amazon.awssdk.auth.credentials.AwsBasicCredentials
import java.net.URI
import zio.nio.file.Path

object ListingObjectsWithPrefix extends ZIOAppDefault {
  // Run in the root of this repo
  // Run docker-compose up before running this app

  override def run =
    for {
      _ <- listInMinio
      _ <- listWithStub
    } yield ()

  def listInMinio =
    list("minio").provide(
      zio.s3
        .live(
          Region.CA_CENTRAL_1,
          AwsBasicCredentials.create("TESTKEY", "TESTSECRET"),
          Some(URI.create("http://127.0.0.1:9000"))
        )
    )

  def listWithStub =
    list("stub").provide(
      stub(Path("./test-data"))
    )

  def list(label: String) =
    for {
      objs <- listObjects(
                "bucket-1",
                ListObjectOptions(prefix = Some("dir1"), maxKeys = 10, delimiter = None, starAfter = None)
              )
      _    <- Console.printLine(s"Objects using $label: " + objs.objectSummaries.map(_.key).mkString(", "))
    } yield ()

}

This will print:

Objects using minio: dir1/hello.txt, dir1/user.csv
Objects using stub:

From my understanding of the AWS API the minio output is correct. I could also reproduce it using an actual s3 bucket.

I've looked into the code and believe I found the cause of the issue. I'll create a PR shortly.