test: NbpService#getFetchDate tests

src/main/java/eu/ztsh/wymiana/config/ClockConfiguration.java

@@ -0,0 +1,16 @@
+package eu.ztsh.wymiana.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.time.Clock;
+
+@Configuration
+public class ClockConfiguration {
+
+    @Bean
+    public Clock clock() {
+        return Clock.systemDefaultZone();
+    }
+
+}

src/main/java/eu/ztsh/wymiana/service/NbpService.java

@@ -1,17 +1,22 @@
 package eu.ztsh.wymiana.service;
 
 import eu.ztsh.wymiana.model.Rates;
+import lombok.RequiredArgsConstructor;
 import org.assertj.core.util.VisibleForTesting;
 import org.springframework.stereotype.Service;
 
+import java.time.Clock;
 import java.time.LocalDate;
 
 /**
  * NBP exchange rates service
  */
 @Service
+@RequiredArgsConstructor
 public class NbpService {
 
+    private final Clock clock;
+
     public double getSellRate(String currency) {
         throw new UnsupportedOperationException("Not implemented yet");
     }