🚧 #70 update fallback service test

src/test/java/com/esp/espflow/service/EsptoolFallBackServiceTest.java

@@ -1,6 +1,8 @@
 package com.esp.espflow.service;
 
 import com.esp.espflow.entity.EspDeviceInfo;
+import com.esp.espflow.exceptions.CanNotBeReadDeviceException;
+import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.InjectMocks;
@@ -17,6 +19,7 @@ class EsptoolFallBackServiceTest {
     private EsptoolFallBackService service;
 
     @Test
+    @DisplayName("An EspDeviceInfo is returned with the port only, no exception is returned.")
     void fallback() {
 
         var espDeviceInfo = EspDeviceInfo.builder()
@@ -28,4 +31,21 @@ void fallback() {
                 .verifyComplete();
 
     }
+
+    @Test
+    @DisplayName("When the service returns an empty Set, because there are no available ports, this is not the case when the ports do not have read permissions.")
+    void fallbackEmptyPorts() {
+
+        StepVerifier.create(this.service.fallbackEmptyPorts())
+                .expectError(CanNotBeReadDeviceException.class)
+                .verify();
+
+        StepVerifier.create(this.service.fallbackEmptyPorts())
+                .expectErrorMatches(error -> error.getMessage().contains("Possibly empty ports"))
+                .verify();
+
+    }
+
+
+
 }