How to hit breakpoint only when some specific unit test is run? - java

I am trying to solve the issue where one of unit tests fails only when I run all the tests in the project.
Thus I would like to come inside some common code only when my failing test is executed. I was trying to find out how to achieve it in Intellij IDEA because there is a feature of condition breakpoints, but for now I fail because don't understand how I can write this type of condition plus it seems that other possibilities don't really allow this.
Is it possible?

Put a breakpoint in the test case that fails (in the image its line 28). Put another break point(in the image its line 42) in the common-code and make that as a conditional one that is disabled till the break point in the test case is hit. To get this window, right click the breakpoint (sometimes you'll have to disable and then re-enable the suspend checkbox).
Hope it helps!

I'm not aware of an IDEA feature which lets you do this, however there are some manual steps that you can take to do this type of debugging:
Add a breakpoint to the first line of the unit test that is failing.
When this breakpoint hits, add another breakpoint in the common class you're interested in.
Alternatively, you can do this in a more automated, repeatable way by making some minor modifications to your unit test code.
Add a public static boolean field to your Unit test class which is set to false by default.
set this to true in the first line of the failing test
Use this field in your test condition. e.g. if your unit test was "ThingTest" and your field "footest" - you're condition will be "ThingTest.footest == true"
Set it to false at the end of your failing test (if you want the follow on tests to run normally)

How about declaring a boolean value, set it to false by default, and only set it to true when you test is failing.
Then you can set a condition on your in your breakpoint, to watch only when the boolean is set to true.
In IntelliJ, you add your breakpoint as per normal, then right click on it, and select View Breakpoint. Another window open, and you can enter your condition.
Hope this helps.

You have two options:
You can like you said use an conditional breakpoint if there is some state (value) in the common code, that is specific to the test you are trying to check. For example a specific string parameter.
You can put an extra breakpoint in the test you are trying to check
before the common code is called from this test. Once this breakpoint
is hit you activate the original breakpoint. You can do this
manually or using the option "Disabled until selected breakpoint is
hit" in the breakpoint dialog of the original breakpoint by
choosing your extra breakpoint in the combo box. If you use the
"automatic"-way you can even uncheck "Suspend" for the extra
breakpoint. This way it will only halt/suspend on your original breakpoint.

Related

Eclipse: How to force execute a particular java statement while debugging?

I have searched and found that indeed Eclipse does not support this 'direct' feature. But, Did I stil miss something? and Is it present in other IDEs?
Let me elaborate my question more -
if a statement falls under execution flow based on an expression evaluation, then why can't we force execute it? (without the execution of the expression).
For example consider this -
... if(bool returnsABoolean) {
<execute some statement>;
}
...
Can the execution of 'if' be skipped and the statement be executed as a 'next statement'? (I obviously can control the value of 'returnAsBoolean' in the Variables view; but can I not skip (in a controlloed manner) all the statements until a particular statement in the execution?)
Highlight the code you want to run and right-click/Execute or press Ctrl+U.
Alternatively to "Execute", use "Display" (Ctrl+Shift+D) or "Inspect" (Ctrl+Shift+I) to see the result.
Looks like you want the 'Display' view - in the Debug perspective, do :
Window -> ShowView -> Display.
You can enter Java statements to execute there (you have to select the bit of text each time that you want to execute)
http://help.eclipse.org/luna/index.jsp?topic=%2Forg.eclipse.jdt.doc.user%2Freference%2Fviews%2Fdisplay%2Fref-display_view.htm
Debugging allows you to run a program interactively while watching the source code and the variables during the execution.
So debugging is nothing but executing program but inspecting the elements during execution but you can not jump into something which is not there in execution.
You can use keyboard buttons F5,F6 ,F8 etc. (For Eclipse) and other Shortcuts during debugging for your convinience but you can't jump to something directly which is not in the execution sequence.
Debugging Shortcuts:
F5 Step into
F6 Step over
F8 Resume and will take you to the break point
Ctrl+Shift+B Toggle breakpoint
Ctrl+Shift+D Display Info of current statement
Ctrl+Shift+I Inspect the selected element
You can Skip some code by the use of breakpoint you can directly jump to specific point and avoid debugging of code which you believe works fine.Or you can jump out code snippet if you want to.
The question really was to set the Instruction pointer at will. This has been discussed and through url's i pasted on the comments above - this is not an eclipse feature (yet).

Is it possible to set a breakpoint on assert in eclipse?

I have a large project consisting of several thousand classes. Today I discovered that for some input, a different result is calculated when running with assertions enabled.
Since the assertion itself doesn't throw an AssertionError (I already have a breakpoint on that one), this means that somewhere hidden in the code is an assertion statement that has an unwanted side effect. The problem is I have no clue which of my >100 assertions is causing the problem.
Since assert is not a method but a keywordin Java, I am at a loss on how to set a breakpoint that will be hit each time assert is called.
Possible workarounds I have found:
commenting out assertions one by one and running the program to finally find the culprit.
run my test case with a code coverage tool like eclEmma to filter out some of the assertion statements.
enabling assertions only for certain packages to narrow down the number of assertions that might be the cause.
doing a search and replace (using regular expressions) to replace assert by a utility method where I can place a breakpoint.
Nonetheless, I would like to know if anyone knows of a way to break on assert, even if the condition evaluates to true.
Goto Run->Add Java Exception Breakpoint
Type 'AssertionError' in search box
Choose java.lang.AssertionError and OK
Now Eclipse will suspend on assert

JUnitCore: Does it hit breakpoint

I am currently learning how to use JUnitCore to run some tests with my application, I think I have it all working fine as it seems to move through the debugger without any problems but I have yet to get my test to print anything to the console System.out.println(...)
Result results= JUnitCore.runClasses(test.class);
System.out.println(results.getRunCount());
When I add a breakpoint to the first line it hits it, but I have another breakpoint inside test.class that when I move to the next breakpoint it never hits, it also wont let me step into the JUnitCore.runClasses(test.class); call either... But it does return 1 for results.getRunCount()
Does anyone know if this is working for me and you are not able to hit breakpoints inside tests this way or is there a problem with JUnitCore.runClasses(test.class)?
I JUnitCore.runClasses are not supposed to print out any message, it will just run the tests.
You will need to add code that will handle any failure and therefore produces some print out.

Eclipse java breakpoints - What is the purpose?

I'm working with the Android tutorial and I just got to the debugging section and I'm wondering what the purpose of a Breakpoint is. I can't tell just yet... is it actually stopping the app so I can be sure it runs up until that point, or can I set multiple breakpoints and use them as markers to "stop and go" from breakpoint to breakpoint checking my code?
A breakpoint is a place where the execution stops, and you can start inspecting the current situation in your debugger. This includes:
the point has actually been reached
the current values of all variables
the ability to change manually all variables
the current stacktrace - i.e. which methods were executed before the current one
the ability to add and execute arbitrary code
the ability to inspect the results of a method invocation, while not actually proceeding with the execution
In addition to that, you can manually step forward, line by line in your application. There are three options:
step into - enters a method which is invoked in the current line
step over - goes to the next line
step return - returns from the current method (to the method that invoked it)
You can set multiple breakpoints if you have multiple places where you want to do any of the above.
Generally speaking, a debugger is a very upgraded version of using System.out.println(..) or log.debug(..) all over the place in order to make sure certain conditions are present. (thanks to BalusC for this point)
You can definitely set multiple breakpoints. The questions answered by the breakpoint (alongside all of Eclipse's other debug tooling) include not only "did it get here" but also "how did it get here" (the stack trace) and "with what values" (you can observe the variables while the code is paused).

Dependent Breakpoints

Is it possible to add Dependent Breakpoints(Not a Conditional Bp) ( Breakpoint1 is enabled if B2 is enabled etc..) in Eclipse...
I know it is possible in Intellij IDea ..but havent found a way to get this working in Eclipse.
Thanks,
Pavan
Eclipse thus far only supports conditional breakpoints, where the execution will suspend if a condition supplied evaluates to true. Thus, you could set the conditional of your breakpoint to be
objectReference == null
and eclipse will hit that break point if and only if that condition evaluates to true. These expressions can be as complex as you would like, but they can only reference values from your source code, not values from the eclipse environment (thus, you can't hit a second break point if a first one was hit, like you originally asked for). This conditional logic can be accessed by right clicking on a breakpoint and selecting "Breakpoint Properties...".
Instead, what I've found helpful is the "Run to Line" ability ([ctrl]+R, in the Run menu). When you're insertion point is on any later line while the execution is suspended, you can use the "Run to line" command to continue execution to that point in the source as if there was a break point set there. In essence, it basically sets and unsets a temporary breakpoint on the line of code your insertion point is at. The greatest part of the command is that it works across files, so that you can hit a break point in one file, go to the file where you would place the dependent break point, [ctrl]+R to that line in the second file. Its a great way to "breakpoint" to a specific line in a file without setting a full breakpoint that will be hit everytime.
Do you mean a conditional breakpoint.
If you mean a conditional breakpoint, it is possible in Eclipse. Right click on the break point select breakpoint properties.
Then you can add the condition.
If you want to toggle a set of breakpoints at once, you can put them in a "Breakpoint Working Set". Group the Breakpoints view by "Breakpoint Working Sets" (view menu > Group By > Breakpoint Working Sets) and you can toggle the whole working set at once.

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