WebSessionStore updates lastAccessTime on retrieve

Now that WebSessionStore is in charge of expiration checks on retrieve
it makes sense to also update the lastAccessTime on retrieve at the
same time, saving the need to call it after a retrieve.

Issue: SPR-15963

spring-web/src/test/java/org/springframework/web/server/session/InMemoryWebSessionStoreTests.java

@@ -17,6 +17,7 @@ package org.springframework.web.server.session;
 
 import java.time.Clock;
 import java.time.Duration;
+import java.time.Instant;
 
 import org.junit.Test;
 
@@ -28,7 +29,7 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 /**
- * Unit tests.
+ * Unit tests for {@link InMemoryWebSessionStore}.
  * @author Rob Winch
  */
 public class InMemoryWebSessionStoreTests {
@@ -36,28 +37,6 @@ public class InMemoryWebSessionStoreTests {
 	private InMemoryWebSessionStore store = new InMemoryWebSessionStore();
 
 
-	@Test
-	public void constructorWhenImplicitStartCopiedThenCopyIsStarted() {
-		WebSession original = this.store.createWebSession().block();
-		assertNotNull(original);
-		original.getAttributes().put("foo", "bar");
-
-		WebSession copy = this.store.updateLastAccessTime(original).block();
-		assertNotNull(copy);
-		assertTrue(copy.isStarted());
-	}
-
-	@Test
-	public void constructorWhenExplicitStartCopiedThenCopyIsStarted() {
-		WebSession original = this.store.createWebSession().block();
-		assertNotNull(original);
-		original.start();
-
-		WebSession copy = this.store.updateLastAccessTime(original).block();
-		assertNotNull(copy);
-		assertTrue(copy.isStarted());
-	}
-
 	@Test
 	public void startsSessionExplicitly() {
 		WebSession session = this.store.createWebSession().block();
@@ -87,8 +66,27 @@ public class InMemoryWebSessionStoreTests {
 		assertNotNull(retrieved);
 		assertSame(session, retrieved);
 
+		// Fast-forward 31 minutes
 		this.store.setClock(Clock.offset(this.store.getClock(), Duration.ofMinutes(31)));
 		WebSession retrievedAgain = this.store.retrieveSession(id).block();
 		assertNull(retrievedAgain);
 	}
+
+	@Test
+	public void lastAccessTimeIsUpdatedOnRetrieve() throws Exception {
+		WebSession session1 = this.store.createWebSession().block();
+		assertNotNull(session1);
+		String id = session1.getId();
+		Instant time1 = session1.getLastAccessTime();
+		session1.save();
+
+		// Fast-forward a few seconds
+		this.store.setClock(Clock.offset(this.store.getClock(), Duration.ofSeconds(5)));
+
+		WebSession session2 = this.store.retrieveSession(id).block();
+		assertNotNull(session2);
+		assertSame(session1, session2);
+		Instant time2 = session2.getLastAccessTime();
+		assertTrue(time1.isBefore(time2));
+	}
 }