I'd like to take this issue. Thank you in advance. Yes @ToxicDreamz, go ahead ☺️  Half way through upgrading, one test case seems to be causing an issue, within the **Serverless** module, in specific the **`SavePersonApiHandlerTest#handleRequestSavePersonException()`** method. I do not have any knowledge of the AWS library, which is why I chose not to mess around with it. 

Initially the DynamoDBMapper was being Mocked with Mockito, and was causing issues once the tests were upgraded to JUnit 5 stating that the class could not be mocked, but as stated in the official Mockito guidelines, a type **should not be mocked if it doesn't belong to you**. See attached link below for details.

https://github.com/mockito/mockito/wiki/How-to-write-good-tests#dont-mock-a-type-you-dont-own

### Suggestion.
A new issue should be opened to address that certain test case, as of now the test case is commented out and marked with a **_TODO_**


### Displayed Error

```
> 
> Caused by: com.amazonaws.SdkClientException: Unable to find a region via the region provider chain. Must provide an explicit region in the builder or setup environment to supply a region.
> 	at com.amazonaws.client.builder.AwsClientBuilder.setRegion(AwsClientBuilder.java:371)
> 	at com.amazonaws.client.builder.AwsClientBuilder.configureMutableProperties(AwsClientBuilder.java:337)
> 	at com.amazonaws.client.builder.AwsSyncClientBuilder.build(AwsSyncClientBuilder.java:46)
> 	at com.iluwatar.serverless.baas.api.SavePersonApiHandlerTest.<clinit>(SavePersonApiHandlerTest.java:58)
> 	... 53 more
```

Error after supplying region`

```
> com.amazonaws.SdkClientException: Unable to load AWS credentials from any provider in the chain
> 
> 	at com.amazonaws.auth.AWSCredentialsProviderChain.getCredentials(AWSCredentialsProviderChain.java:131)
> 	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.getCredentialsFromContext(AmazonHttpClient.java:1164)
> 	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.runBeforeRequestHandlers(AmazonHttpClient.java:762)
> 	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:724)
> 	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:717)
> 	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:699)
> 	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:667)
> 	at com.amazonaws.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:649)
> 	at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:513)
> 	at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.doInvoke(AmazonDynamoDBClient.java:3082)
> 	at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.invoke(AmazonDynamoDBClient.java:3058)
> 	at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.executePutItem(AmazonDynamoDBClient.java:2119)
> 	at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.putItem(AmazonDynamoDBClient.java:2094)
> 	at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$SaveObjectHandler.doPutItem(DynamoDBMapper.java:883)
> 	at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$1.executeLowLevelRequest(DynamoDBMapper.java:536)
> 	at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$SaveObjectHandler.execute(DynamoDBMapper.java:733)
> 	at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.save(DynamoDBMapper.java:623)
> 	at com.amazonaws.services.dynamodbv2.datamodeling.AbstractDynamoDBMapper.save(AbstractDynamoDBMapper.java:123)
> 	at com.iluwatar.serverless.baas.api.SavePersonApiHandler.handleRequest(SavePersonApiHandler.java:50)
> 	at com.iluwatar.serverless.baas.api.SavePersonApiHandlerTest.handleRequestSavePersonSuccessful(SavePersonApiHandlerTest.java:76)
> 	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> 	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
> 	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.base/java.lang.reflect.Method.invoke(Method.java:567)
> 	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:675)
> 	at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
> 	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:125)
> 	at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:132)
> 	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:124)
> 	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:74)
> 	at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
> 	at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
> 	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:104)
> 	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:62)
> 	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:43)
> 	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:35)
> 	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
> 	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
> 	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:202)
> 	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
> 	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:198)
> 	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
> 	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:69)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135)
> 	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
> 	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
> 	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
> 	at java.base/java.util.ArrayList.forEach(ArrayList.java:1507)
> 	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
> 	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
> 	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
> 	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
> 	at java.base/java.util.ArrayList.forEach(ArrayList.java:1507)
> 	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
> 	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
> 	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
> 	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
> 	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
> 	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
> 	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
> 	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
> 	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:229)
> 	at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:197)
> 	at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:211)
> 	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191)
> 	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128)
> 	at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:69)
> 	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
> 	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
> 	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)

```

 Overall the serverless module needs to be looked at, more tests are causing the same issues due to them not being able to be mocked. @ToxicDreamz FYI: I created #1505 which removes the dependency of `subclass-sandbox` to Rule, which is a JUnit 4 only feature. @stefanbirkner Okay, thank you for the heads up. I'll wait for @iluwatar to merge that PR, until I continue with that module. It's merged now Using JUnit 5 in Trampoline module. PR #1529 created. I want to work on this issue if its is still unassigned . Ok @sgarg5794  I'm working on updating all the modules to JUnit5 right now. @ohbus  Sure @charlesfinley you're good to go! > Sure @charlesfinley you're good to go!

Sorry I opened a new PR for this - #1668  @charlesfinley no need to be sorry for 😄  It is easier for us to review code in smaller chunks and this helps a lot 💯 

Thank you so much for your help! > @charlesfinley no need to be sorry for 😄 It is easier for us to review code in smaller chunks and this helps a lot 💯
> 
> Thank you so much for your help!

This issue should probably be closed since the PR was merged and we have 2 new issues identifying the only modules lacking JUnit5.  @charlesfinley great work!

We will close this issue for sure. This issue has been partially addressed using #1542 and #1668 thanks to @charlesfinley 

Tests from two modules [**serverless**](https://github.com/iluwatar/java-design-patterns/tree/master/serverless) and [**naked-objects**](https://github.com/iluwatar/java-design-patterns/tree/master/naked-objects) are not being executed.

Respective issues have been opened for resolving the tests in favour of these two modules.
- [ ] #1667
- [ ] #1669

Resolving these two issues should close this [current issue](https://github.com/iluwatar/java-design-patterns/issues/1500) @iluwatar let me know how can I help with this, I am confused about the status of the what has been resolved and what is pending. Thanks for asking @anuragagarwal561994. I think the only remaining issue is that naked objects pattern still uses JUnit 4. Resolving this is covered by issues https://github.com/iluwatar/java-design-patterns/issues/1669 and https://github.com/iluwatar/java-design-patterns/issues/1683. I think we should close this task.
Use the same JUnit version everywhere
At the moment there are some modules that are still using JUnit 4. Most of the codebase uses JUnit 5, but even with that there are different versions. For example `unit-of-work` and `partial-response` declare their own versions.

In this ticket let's try to apply the same version of JUnit 5 everywhere upgrading from JUnit 4 where needed.


## This issue has been partially addressed using #1542 and #1668

Tests from two modules [**serverless**](https://github.com/iluwatar/java-design-patterns/tree/master/serverless) and [**naked-objects**](https://github.com/iluwatar/java-design-patterns/tree/master/naked-objects) are not being executed.

Respective issues have been opened for resolving the tests in favour of these two modules.
- [x] #1667 against [**serverless**](https://github.com/iluwatar/java-design-patterns/tree/master/serverless)
- [ ] #1669 against [**naked-objects**](https://github.com/iluwatar/java-design-patterns/tree/master/naked-objects)

Resolving these two issues should close this [current issue](https://github.com/iluwatar/java-design-patterns/issues/1500)
trampoline/pom.xml trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java
trampoline/pom.xml trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java
trampoline/src/test/java/com/iluwatar/trampoline/TrampolineAppTest.java
diff --git a/trampoline/pom.xml b/trampoline/pom.xml
index fff117bf8a72..d78236473725 100644
--- a/trampoline/pom.xml
+++ b/trampoline/pom.xml
@@ -35,11 +35,6 @@
     </parent>
     <artifactId>trampoline</artifactId>
     <dependencies>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <scope>test</scope>
-        </dependency>
 
         <dependency>
             <groupId>org.junit.jupiter</groupId>
diff --git a/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java b/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java
index 36ad73e3e961..16e34ff10e01 100644
--- a/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java
+++ b/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java
@@ -98,12 +98,12 @@ public T get() {
         return trampoline(this);
       }
 
-      T trampoline(final Trampoline<T> trampoline) {
+      private T trampoline(final Trampoline<T> trampoline) {
         return Stream.iterate(trampoline, Trampoline::jump)
             .filter(Trampoline::complete)
             .findFirst()
             .map(Trampoline::result)
-            .orElseThrow();
+            .get();
       }
     };
   }

diff --git a/trampoline/src/test/java/com/iluwatar/trampoline/TrampolineAppTest.java b/trampoline/src/test/java/com/iluwatar/trampoline/TrampolineAppTest.java
index c5d6571cdd51..664a95634f5c 100644
--- a/trampoline/src/test/java/com/iluwatar/trampoline/TrampolineAppTest.java
+++ b/trampoline/src/test/java/com/iluwatar/trampoline/TrampolineAppTest.java
@@ -23,10 +23,9 @@
 
 package com.iluwatar.trampoline;
 
-import static org.junit.Assert.assertEquals;
-
-import org.junit.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import org.junit.jupiter.api.Test;
 
 /**
  * Test for trampoline pattern.
@@ -37,7 +36,7 @@ public class TrampolineAppTest {
   @Test
   public void testTrampolineWithFactorialFunction() {
     long result = TrampolineApp.loop(10, 1).result();
-    assertEquals("Be equal", 3628800, result);
+    assertEquals(3_628_800, result);
   }
 
 }
\ No newline at end of file
