/home/kai/Dokumente/yourshouter/http-resources/src/test/java/de/juplo/httpresources/HttpResourceNotExpiredFetchModifiedTest.java

+    package de.juplo.httpresources;
+
+    import org.junit.jupiter.api.BeforeEach;
+    import org.junit.jupiter.api.DisplayName;
+    import org.junit.jupiter.api.Test;
+    import org.junit.jupiter.api.extension.ExtendWith;
+    import org.mockito.Mock;
+    import org.mockito.junit.jupiter.MockitoExtension;
+    import org.mockito.junit.jupiter.MockitoSettings;
+    import org.mockito.quality.Strictness;
+    import org.slf4j.Logger;
+    import org.slf4j.LoggerFactory;
+    import org.springframework.cache.support.NoOpCache;
+    import org.springframework.http.HttpHeaders;
+    import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+    import java.net.URI;
+    import java.time.Clock;
+    import java.time.ZoneId;
+
+    import static de.juplo.httpresources.TestUtil.*;
+    import static org.assertj.core.api.Assertions.assertThat;
+    import static org.mockito.ArgumentMatchers.any;
+    import static org.mockito.ArgumentMatchers.eq;
+    import static org.mockito.Mockito.*;
+
+
+    @DisplayName(("HttpResource - Fetched - Not Expired - Fetch: Modified"))
+    @ExtendWith({ SpringExtension.class, MockitoExtension.class })
+    @MockitoSettings(strictness = Strictness.LENIENT)
+    public class HttpResourceNotExpiredFetchModifiedTest
+    {
+      private final static Logger LOG = LoggerFactory.getLogger(HttpResourceNotExpiredFetchModifiedTest.class);
+
+      @Mock
+      HttpResourceFetcher fetcher;
+
+      HttpResources resources;
+      URI uri;
+      HttpResource resource;
+
+
+      /************** SETUP */
+
+      @BeforeEach
+      public void setUp()
+      {
+        Clock clock = Clock.fixed(NOW.toInstant(), ZoneId.of("GMT"));
+        resources = new HttpResources(fetcher, clock);
+        uri = URI.create("http://foo/bar");
+        resource = new HttpResource(resources, fetcher, clock, uri);
+        resource.data = DATA_NOT_EXPIRED;
+
+        // Everything is possible, nothing is necessary: Only defines behavior!
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MIME_TYPE_CONTENT_TYPE_HTML);
+
+        when(fetcher.fetch(any(), any())).thenReturn(DATA_UPDATED);
+      }
+
+
+      /*************** For calls, that do not trigger a fetch see: HttpResourceNotExpiredTest */
+
+
+      /*************** Calls, that trigger a fetch */
+
+      @Test
+      @DisplayName(("call to fetch() triggers fetch"))
+      public void test_fetch_TriggersFetch()
+      {
+        LOG.info("<-- start of test-case");
+
+        resource.fetch();
+
+        // Do not verify implementation: Only verify necessary outcome!
+        verify(fetcher).fetch(eq(uri), any());
+      }
+
+
+      /*************** Results for calls, that does trigger a fetch */
+
+      @Test
+      @DisplayName(("fetch() returns true, if fetcher returned true"))
+      public void test_fetch_ReturnsTrueIfFetcherReturnedFalse()
+      {
+        LOG.info("<-- start of test-case");
+
+        assertThat(resource.fetch()).isTrue();
+      }
+
+
+      /*************** Expected state after calls that trigger a fetch */
+
+      @Test
+      @DisplayName(("fetch() updates data"))
+      public void test_fetch_UpdatesData()
+      {
+        LOG.info("<-- start of test-case");
+
+        resource.fetch();
+
+        assertThat(resource.data).isSameAs(DATA_UPDATED);
+      }
+    }
+