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LazyInitializationException in unit tests under Spring-Data/Spring-Boot

My unit tests are seeing org.hibernate.LazyInitializationException: could not initialize proxy [org.openapitools.entity.MenuItem#5] - no Session. I'm not sure why they expect a session in a unit test. I'm trying to write to an in-memory h2 database for the unit tests of my Controller classes that implement the RESTful APIs. I'm not using any mock objects for the test, because I want to test the actual database transactions. This worked fine when I was using Spring-Boot version 1.x, but broke when I moved to version 2. (I'm not sure if that's what caused the tests to break, since I made lots of other changes. My point is that my code has passed these tests already.)
My Repositories extend JPARepository, so I'm using a standard Hibernate interface.
There are many answers to this question on StackOverflow, but very few describe a solution that I could use with Spring-Data.
Addendum: Here's a look at the unit test:
#Test
public void testDeleteOption() throws ResponseException {
MenuItemDto menuItemDto = createPizzaMenuItem();
ResponseEntity<CreatedResponse> responseEntity
= adminApiController.addMenuItem(menuItemDto);
final CreatedResponse body = responseEntity.getBody();
assertNotNull(body);
Integer id = body.getId();
MenuItem item = menuItemApiController.getMenuItemTestOnly(id);
// Hibernate.initialize(item); // attempted fix blows up
List<String> nameList = new LinkedList<>();
for (MenuItemOption option : item.getAllowedOptions()) { // blows up here
nameList.add(option.getName());
}
assertThat(nameList, hasItems("pepperoni", "olives", "onions"));
// ... (more code)
}
My test application.properties has these settings
spring.datasource.url=jdbc:h2:mem:pizzaChallenge;DB_CLOSE_ON_EXIT=FALSE
spring.datasource.username=pizza
spring.datasource.password=pizza
spring.jpa.show-sql=true

This is not standard Hibernate, but spring data. You have to understand that Hibernate uses lazy loading to avoid loading the whole object graph from the database. If you close the session or connection to the database e.g. by ending a transaction, Hibernate can't lazy load anymore and apparently, your code tries to access state that needs lazy loading.
You can use #EntityGraph on your repository to specify that an association should be fetched or you avoid accessing the state that isn't initialized outside of a transaction. Maybe you just need to enlarge the transaction scope by putting #Transactional on the method that calls the repository and accesses the state, so that lazy loading works.

I found a way around this. I'm not sure if this is the best approach, so if anyone has any better ideas, I'd appreciate hearing from them.
Here's what I did. First of all, before reading a value from the lazy-loaded entity, I call Hibernate.initialize(item);
This throws the same exception. But now I can add a property to the test version of application.properties that says
spring.jpa.properties.hibernate.enable_lazy_load_no_trans=true
Now the initialize method will work.
P.S. I haven't been able to find a good reference for Spring properties like this one. If anyone knows where I can see the available properties, I'd love to hear about it. The folks at Spring don't do a very good job of documenting these properties. Even when they mention a specific property, they don't provide a link that might explain it more thoroughly.

How to avoid toBlocking in RxJava 2

Integrating a RxJava in springboot application using Observable we are able to get the data from the service. But I have a doubt in using toBlocking() method, because I've read many forum postings saying it has issues in production server. See my below code,
Sample Code with toBlocking():
userService.getUsers()
.subscribeOn(Schedulers.io())
.toBlocking()
.single();
I want to change the above to get the user object instead of Observable object.
For example:
User user = new User();
userService.getUsers().subscribe(u ->user = u );
Here a variable user is declared globally in the class it work fine, but inside method it shows an error.

You probably want something like blockingFirst:
final User user = userService
.getUsers()
.blockingFirst()
I'd encourage you to think about if this is the right thing to do, though (do you really need to block and jump out of the reactive world for this use case?. As #akarnokd said, read Getting Started)

JUnit - How to unit test method that reads files in a directory and uses external libraries

I have this method that I am using in a NetBeans plugin:
public static SourceCodeFile getCurrentlyOpenedFile() {
MainProjectManager mainProjectManager = new MainProjectManager();
Project openedProject = mainProjectManager.getMainProject();
/* Get Java file currently displaying in the IDE if there is an opened project */
if (openedProject != null) {
TopComponent activeTC = TopComponent.getRegistry().getActivated();
DataObject dataLookup = activeTC.getLookup().lookup(DataObject.class);
File file = FileUtil.toFile(dataLookup.getPrimaryFile()); // Currently opened file
// Check if the opened file is a Java file
if (FilenameUtils.getExtension(file.getAbsoluteFile().getAbsolutePath()).equalsIgnoreCase("java")) {
return new SourceCodeFile(file);
} else {
return null;
}
} else {
return null;
}
}
Basically, using NetBeans API, it detects the file currently opened by the user in the IDE. Then, it loads it and creates a SourceCodeFile object out of it.
Now I want to unit test this method using JUnit. The problem is that I don't know how to test it.
Since it doesn't receive any argument as parameter, I can't test how it behaves given wrong arguments. I also thought about trying to manipulate openedProject in order to test the method behaviour given some different values to that object, but as far as I'm concernet, I can't manipulate a variable in JUnit that way. I also cannot check what the method returns, because the unit test will always return null, since it doesn't detect any opened file in NetBeans.
So, my question is: how can I approach the unit testing of this method?

Well, your method does take parameters, "between the lines":
MainProjectManager mainProjectManager = new MainProjectManager();
Project openedProject = mainProjectManager.getMainProject();
basically fetches the object to work on.
So the first step would be to change that method signature, to:
public static SourceCodeFile getCurrentlyOpenedFile(Project project) {
...
Of course, that object isn't used, except for that null check. So the next level would be to have a distinct method like
SourceCodeFile lookup(DataObject dataLookup) {
In other words: your real problem is that you wrote hard-to-test code. The "default" answer is: you have to change your production code, to make easier to test.
For example by ripping it apart, and putting all the different aspects into smaller helper methods.
You see, that last method lookup(), that one takes a parameter, and now it becomes (somehow) possible to think up test cases for this. Probably you will have to use a mocking framework such as Mockito to pass mocked instances of that DataObject class within your test code.
Long story short: there are no detours here. You can't test your code (in reasonable ways) as it is currently structured. Re-structure your production code, then all your ideas about "when I pass X, then Y should happen" can work out.
Disclaimer: yes, theoretically, you could test the above code, by heavily relying on frameworks like PowerMock(ito) or JMockit. These frameworks allow you to contol (mock) calls to static methods, or to new(). So they would give you full control over everything in your method. But that would basically force your tests to know everything that is going on in the method under test. Which is a really bad thing.

Use placeholders in feature files

I would like to use placeholders in a feature file, like this:
Feature: Talk to two servers
Scenario: Forward data from Server A to Server B
Given MongoDb collection "${db1}/foo" contains the following record:
"""
{"key": "value"}
"""
When I send GET "${server1}/data"
When I forward the respone to PUT "${server2}/data"
Then MongoDB collection "${db2}/bar" MUST contain the following record:
"""
{"key": "value"}
"""
The values of ${server1} etc. would depend on the environment in which the test is to be executed (dev, uat, stage, or prod). Therefore, Scenario Outlines are not applicable in this situation.
Is there any standard way of doing this? Ideally there would be something which maintains a Map<String, String> that can be filled in a #Before or so, and runs automatically between Cucumber and the Step Definition so that inside the step definitions no code is needed.
Given the following step definitions
public class MyStepdefs {
#When("^I send GET "(.*)"$)
public void performGET(final String url) {
// …
}
}
And an appropriate setup, when performGET() is called, the placeholder ${server1} in String uri should already be replaced with a lookup of a value in a Map.
Is there a standard way or feature of Cucumber-Java of doing this? I do not mind if this involves dependency injection. If dependency injection is involved, I would prefer Spring, as Spring is already in use for other reasons in my use case.

The simple answer is that you can't.
The solution to your problem is to remove the incidental details from your scenario all together and access specific server information in the step defintions.
The server and database obviously belong together so lets describe them as a single entity, a service.
The details about the rest calls doesn't really help to convey what you're
actually doing. Features don't describe implementation details, they describe behavior.
Testing if records have been inserted into the database is another bad practice and again doesn't describe behavior. You should be able to replace that by an other API call that fetches the data or some other process that proves the other server has received the information. If there are no such means to extract the data available you should create them. If they can't be created you can wonder if the information even needs to be stored (your service would then appear to have the same properties as a black hole :) ).
I would resolve this all by rewriting the story such that:
Feature: Talk to two services
Scenario: Forward foobar data from Service A to Service B
Given "Service A" has key-value information
When I forward the foobar data from "Service A" to "Service B"
Then "Service B" has received the key-value information
Now that we have two entities Service A and Service B you can create a ServiceInformationService to look up information about Service A and B. You can inject this ServiceInformationService into your step definitions.
So when ever you need some information about Service A, you do
Service a = serviceInformationService.lookup("A");
String apiHost = a.getApiHost():
String dbHost = a.getDatabaseHOst():
In the implementation of the Service you look up the property for that service System.getProperty(serviceName + "_" + apiHostKey) and you make sure that your CI sets A_APIHOST and A_DBHOST, B_APIHOST, B_DBHOST, ect.
You can put the name of the collections in a property file that you look up in a similar way as you'd look up the system properties. Though I would avoid direct interaction with the DB if possible.

The feature you are looking for is supported in gherkin with qaf. It supports to use properties defined in properties file using ${prop.key}. In addition it offers strong resource configuration features to work with different environments. It also supports web-services

How do I make session/cache variables available to my main.html template?

I'm using Play Framework and setting a cache value as such:
String sessionId = Scope.Session.current().getId();
Cache.set(sessionId + "_user", "Doser");
and I want to ouput the value in my main.html without adding the value to every single controller in my application.
How do I achieve this in Play?

The other option you have for this, is to create an action in your controller that uses the #Before annotation, and then add the value using renderArgs().
I answered a previous question which I think is very similar to your requirements.
Does Play Framework support "snippets"?
You should also be aware that all session variables are available within your template, by default. You can see all the implicit objects that are available in the template in the Template Documentation here -- http://www.playframework.org/documentation/1.2.2/templates#implicits.

I need to stop answering my own questions.
I've created a tag as described in the link below, and it works perfectly:
http://www.playframework.org/documentation/1.2.2/templates#tags