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Is there a JUnit equivalent of Jest's expect.assertions(number)?

In JavaScript, the library Jest has a delightful semantic - expect.assertions(number) which verifies that a certain number of assertions are called during a test, for example of async code:
test('doAsync calls both callbacks', () => {
expect.assertions(2);
function callback1(data) {
expect(data).toBeTruthy();
}
function callback2(data) {
expect(data).toBeTruthy();
}
doAsync(callback1, callback2);
});
Is there a similar semantic available in JUnit or other Java unit testing libraries?
If so, please feel very welcome to give an example, such as using CompleteableFuture or as appropriate.

How to fix this problem with assertEquals in Junit?

Please help me with the following problem, My Junit test fails because my output is
"09:39:43.704 [main] INFO by.iba.gomel.ShapeController - 145"
But i need just "145" ShapeController.LOGGER.info("{}", ShapeController.sum);
#Test
public void testSumma() {
final Shape[] newShapes = new Shape[5];
ShapeController.initializeArray(newShapes);
ShapeController.summa(newShapes);
Assert.assertEquals("these objects should be equal", "145", this.log.getLog());
}

If you are not changing the log format and the class name you can use this.log.getLog().split("ShapeController - ")[1].
But be wary of such hard-coded things. Anyways if you change something this test case will break and notify you.

You can use Java Library such as Hamcrest to make an assertion in a sentence if it ends with the number or word, such as 1 :
assertThat("myStringOfNote", endsWith("Note"))
This can be translated into your use case as :
assertThat(this.log.getLog(), endsWith("145"))

JUnit test case failed

I have a simple test case:
public class FileManagerTest {
String dirPath = “/myDir/”
#Before
public void setUp() {
mFileManager = MyFileManager.getInstance();
}
#Test
private void testPersistFiles() {
System.out.println(“testPersistFiles()…”);
//it deletes old files & persists new files to /myDir/ directory
boolean successful =mFileManager.persistFiles();
Assert.assertTrue(successful);
}
#Test
public void testGetFiles() {
System.out.println(“testGetFiles()…”);
mFileManager.persistFiles();
//I double checked, the persistFiles() works, the files are persisted.
List<File> files = mFileManager.getFilesAtPath(dirPath);
Assert.assertNotNull(files); //Failure here!!!!
}
#Test
public void testGetFilesMap() {
System.out.println(“testGetFilesMap()…”);
mFileManager.persistFiles();
Map<String, File> filesMap = mFileManager.getFilesMapAtPath(dirPath);
Assert.assertNotNull(files);
}
}
The persistFiles() function in FileManager delete all files under /myDir/ then persist files again.
As you see above, I have a System.out.println(…) in each test function. When I run it , I can see all the prints in the following order:
testGetFilesMap()…
testGetFiles()…
testPersistFiles()…
However, test is failed at testGetFiles(). Two things I don't understand:
I don’t understand, it is failed at testGetFiles() why I can still see the print testPersistFiles() which sounds like even it is failed, it doesn't stop running, but continues to run the next test testPersistFiles()? What is happening behind the scene in JUnit test case??
Another thing I don’t understand is why testGetFiles() is failed? I can see log that the persistFiles() has persisted files. Why it got null after that?

I don’t understand, it is failed at testGetFiles() why I can still see the print testPersistFiles() which sounds like even it is failed, i
That is how unit testing works. Each test should be isolated and working using only its set of data. Unit test frameworks run every test so you can see which parts of the system work and which do not, they do not stop on the first failure.

mFileManager.getFilesAtPath(dirPath);
You are not searching the files in the right place
String dirPath = “/myDir/”
Are you sure that this path is ok? with a slash before the directory name?

For each of your tests, JUnit creates a separate instance of that class and runs it. Since you seem to have 3 tests, JUnit will create 3 instances of your class, execute #Before on each of them to initialize state, and then run them.
The order in which they are run is typically the order in which the tests are written but this is not guaranteed.
Now about the print statement - you see that it's the first statement in your test so it will be executed. Then mFileManager.persistFiles(); is executed. For some reason it returns a false and hence the test fails.
As to why it returns false, you can run a local debugger, put a break point at the beginning of that method, single-step and see.

How make JUnit print assertion results

How can I get the results of my JUnit assertions to be printed [to standard output]?
I have some tests like this:
#Test
public void test01()
{
Position p = getPositionAt('a', 1);
assertNotNull("a1 exists", p);
assertNotNull("figure exists a1", p.getFigure());
p = getPositionAt('a', 2);
assertNotNull("exists a2", p);
assertNull("figure exists a2", p.getFigure());
p = getPositionAt('b', 1);
assertNotNull("exists b1", p);
assertNull("figure exists b1", p.getFigure());
}
This is the printed output format I am hoping to get:
a1 exists -success
figure exists a1 -success
exists a2 -success
figure exists a2 -succcess
exists b1 -succcess
figure exists b1 -failed
Is there way to do this using runners and suites? Or does there exist any assertSuccess(), assertFailed() methods?

First, you have two issues not one. When an assertion fails, an AssertionError exception is thrown. This prevents any assertion past this point from being checked. To address this you need to use an ErrorCollector.
Second, I do not believe there is any way built in to JUnit to do this. However, you could implement your own methods that wrap the assertions:
public static void assertNotNull(String description, Object object){
try{
Assert.assertNotNull(description, object);
System.out.println(description + " - passed");
}catch(AssertionError e){
System.out.println(description + " - failed");
throw e;
}
}

All the assertXXX methods have a form that allows for displaying a String on error:
assertNotNull("exists a2", p); // prints "exists a2" if p is null
There is no particular value in printing a message on success.
EDIT
Junit typically provides 2 forms of an assert. To follow the example above, you can test for a null value in 1 of 2 ways:
assertNotNull(p)
or
assertNotNull("my message on failure", p)
The framework will print the error messages with no other effort required by you (it's provided by the framework).
To test for exceptions you would use the following pattern:
try{
someCall();
catch(Exception e){
fail(): // exception shouldn't happen, use assertTrue(true) if it should
}
Again, there are versions of these methods for adding a message
Check the API

One last resort option is to pair each assert with a corresponding System.out.println, though obviously that is less than ideal. Still, it will solve the problem if all else fails.

Existing Answers/Comments here contain enough info to understand how to print something based on JUnit assertions - but they also explain how doing so is probably not what you actually want to do, and is probably missing the point of running unit tests in the first place.
You should be viewing the results of the tests themselves, instead of trying to print something while you don't understand how/where to view test results themselves.
Now then how/where to view results themselves depends on how you are running your tests - you need to understand how you are running your tests, and then research how to view test results according to how you are running them. Here are a few (but not limited to) examples:
Running tests in IntelliJ
Running tests in Eclipse
Running tests on command line
Running tests in Jenkins

Junit preconditions and test data

I have a java assignment to create an address book then test and evaluate it. I have created it and created some junit tests. In the deliverables section of the assignment it says to list all the test cases for the full program in a table along with:
A unique id
a description of the test
pre-conditions for running the test
the test data
the expected result
Could somebody tell me what they mean by the preconditions and the test data for the test below:
public void testGetName()
{
Entry entry1 = new Entry("Alison Murray", "34 Station Rd", "Workington", "CA14 4TG");
assertEquals("Alison Murray",entry1.getName()); }
Tried emailing the tutor (im a distanct learner) but its taking too long to get a reply. Would the pre-condition be that entry1 needs populated? Test data: "Alison Murray"? Any help is apreciated

There are two types of checks with JUnit:
assertions (org.junit.Assert.*);
assumptions (org.junit.Assume.*).
Assertions are usually used to check your test results. If teh result is not what was expected, then the test fails.
Assumptions are used to check it test data are valid (if they match the test case). If they don't, the test is cancelled (without any error).
As I read your code sample: there are no preconditions and the test data would be entry1.