#28869 - example for setting policies in docs (persistence testkit)

akka-docs/src/test/java/jdocs/persistence/testkit/PersistenceTestKitPolicySampleTest.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2020 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package jdocs.persistence.testkit;
+
+import akka.actor.testkit.typed.javadsl.TestKitJunitResource;
+import akka.actor.typed.ActorRef;
+import akka.persistence.testkit.JournalOperation;
+import akka.persistence.testkit.PersistenceTestKitPlugin;
+import akka.persistence.testkit.ProcessingPolicy;
+import akka.persistence.testkit.ProcessingResult;
+import akka.persistence.testkit.ProcessingSuccess;
+import akka.persistence.testkit.StorageFailure;
+import akka.persistence.testkit.WriteEvents;
+import akka.persistence.testkit.javadsl.PersistenceTestKit;
+import akka.persistence.typed.PersistenceId;
+import com.typesafe.config.ConfigFactory;
+import jdocs.AbstractJavaTest;
+import org.junit.Before;
+import org.junit.ClassRule;
+import org.junit.Test;
+
+// #policy-test
+public class PersistenceTestKitPolicySampleTest extends AbstractJavaTest {
+
+  @ClassRule
+  public static final TestKitJunitResource testKit =
+      new TestKitJunitResource(
+          PersistenceTestKitPlugin.getInstance()
+              .config()
+              .withFallback(ConfigFactory.defaultApplication()));
+
+  PersistenceTestKit persistenceTestKit = PersistenceTestKit.create(testKit.system());
+
+  @Before
+  public void beforeEach() {
+    persistenceTestKit.clearAll();
+    persistenceTestKit.returnDefaultPolicy();
+  }
+
+  @Test
+  public void test() {
+    SampleEventStoragePolicy policy = new SampleEventStoragePolicy();
+    persistenceTestKit.withPolicy(policy);
+
+    PersistenceId persistenceId = PersistenceId.ofUniqueId("some-id");
+    ActorRef<YourPersistentBehavior.Cmd> ref =
+        testKit.spawn(YourPersistentBehavior.create(persistenceId));
+
+    YourPersistentBehavior.Cmd cmd = new YourPersistentBehavior.Cmd("data");
+    ref.tell(cmd);
+
+    persistenceTestKit.expectNothingPersisted(persistenceId.id());
+  }
+
+  static class SampleEventStoragePolicy implements ProcessingPolicy<JournalOperation> {
+    @Override
+    public ProcessingResult tryProcess(String persistenceId, JournalOperation processingUnit) {
+      if (processingUnit instanceof WriteEvents) {
+        return StorageFailure.create();
+      } else {
+        return ProcessingSuccess.getInstance();
+      }
+    }
+  }
+}
+// #policy-test