Repliquei o código que vi na video-aula 4 do módulo 4. Testes automatizados, mas na execução a minha variável baos (responsável por armazer as strings) está vazia.

Meu código:

public class AbrigoServiceTest {
  private ClientHttpConfiguration client = mock(ClientHttpConfiguration.class);
  private HttpResponse<String> response = mock(HttpResponse.class);
  private AbrigoService abrigoService = new AbrigoService(client);
  private Abrigo abrigo = new Abrigo("Teste", "61981880392", "abrigo_alura@gmail.com");

  @Test
  public void deveVerificarSeDispararRequisicaoGetSeraChamado() throws IOException, InterruptedException {
    abrigo.setId(0L);
    String expectedAbrigosCadastrados = "Abrigos cadastrados:";
    String expectedIdENome = "0 - Teste";

    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    PrintStream printStream = new PrintStream(baos);
    System.out.println(printStream);

    when(response.body()).thenReturn("[{" + abrigo.toString() + "}]");
    when(client.dispararRequisicaoGet(anyString())).thenReturn(response);

    abrigoService.listarAbrigo();

    String[] lines = baos.toString(StandardCharsets.UTF_8).split(System.lineSeparator());
    System.out.println(Arrays.toString(lines)); // adicionado para verificar o conteúdo de lines
    String actualAbrigosCadastrados = lines[0];
    String actualIdENome = lines[1];

    Assertions.assertEquals(expectedAbrigosCadastrados, actualAbrigosCadastrados);
    Assertions.assertEquals(expectedIdENome, actualIdENome);
  }
}

Resultado da execução do teste:

Connected to the target VM, address: '127.0.0.1:51449', transport: 'socket'
WARNING: A Java agent has been loaded dynamically (C:\Users\lucas\.m2\repository\net\bytebuddy\byte-buddy-agent\1.14.12\byte-buddy-agent-1.14.12.jar)
WARNING: If a serviceability tool is in use, please run with -XX:+EnableDynamicAgentLoading to hide this warning
WARNING: If a serviceability tool is not in use, please run with -Djdk.instrument.traceUsage for more information
WARNING: Dynamic loading of agents will be disallowed by default in a future release
OpenJDK 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended
java.io.PrintStream@4f20a5e0
Abrigos cadastrados:
0 - Teste
[]

java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1

    at br.com.alura.service.AbrigoServiceTest.deveVerificarSeDispararRequisicaoGetSeraChamado(AbrigoServiceTest.java:44)
    at java.base/java.lang.reflect.Method.invoke(Method.java:580)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)

Disconnected from the target VM, address: '127.0.0.1:51449', transport: 'socket'

Process finished with exit code -1

Debug da linha 41 (String[] lines = ...):