Daniel John Debrunner wrote:

Manjula G Kutty wrote:

Hi,

I'm very new to the junit testing. So I picked lang/currentof.java as my first test to convert to junit. I did it with the very little knowledge I have and also with the help of the Wiki. I got the test running to some extend but then I get some errors on the testUpdate. The error says "Invalid cursor state" . I tried using printf to see how the control goes and I could see the number of rows expected and got are 0. So it should come out of the verifycount method, but it is not. There may be 3 reasons for this. Either I didn't understand the test fully or did something wrong while converting or there may be bug . Can someone please review the attached code(I know it is not a very clean code) and let me know what went wrong??


One of the possibly unexpected facts about Junit when coming from the old derby test harness is understanding the setup and tearDown methods of a test class. A test class contains fixtures, methods that start with 'test' which are individual test cases. The setup and tearDown in a test class are run for *each* fixture, thus I think twice in this class, once for testUpdate() and once for testDelete(). I think a common mistake is to assume they are run once for all the fixtures. Could that be the case here?

Another issue is that the order of fixtures is not guaranteed when adding a suite using MyTest.class. This is intentional since fixtures should be standalone test cases, thus if your test depends on testUpdate() running before testDelete() you may see intermittant problems.

One more question where will the test database gets created? Even the test fails will the teardown method deletes all tables? If so is there a mechanism to access the database or copy the database instance when the test went wrong?


Nothing exists at the moment, apart from working in a debugger. Please feel free to implement something.

Dan.


Here is some information I gathered during the process of this test conversion. Thought it will be useful to people like me who are new to the junit world. Please feel free to add more information and also correct if I went wrong in any place.

The Wiki pages available in the Apache Derby site is very useful to a get initial startup.

setup and teardown methods will run per fixture. not once for the whole test. By default all tests should be able to run in embedded or N/W server mode, without much user intervention

Most of the lang tests needs to be run with only embedded to avoid the overhead of testduration. There is no point in running the same tests against networkserver if the test is doing simple SQL query tests. But tests for hold cursors and updateableResultSets are good candidates for the both.

There are some more Assert methods in the java/testing/junit package which can be used for most of SQL tests, like for getting the numberof rows updated for a prepared statement execution you can use assertUpdateCount(PreparedStatement, rows expected); If the number of rows returned are not equal to the rows expected, the test will fail.

You can get rid of most of the try catch block with the assert methods. I used try/catch methods only for negative tests, where I have to catch the SQL exception. which can also be eliminated using the assertStatementError() method
To catch the SQLException you can use assertSQLState() method

If you are using eclipse for the test development then click on the class name and you can see all the methods in the right most tab and if you sort them you can view all the assert methods together. Also there is a very good java doc for the Assert class. you can find it at http://junit.sourceforge.net/javadoc/junit/framework/Assert.html

It will be nice if we can add a functionality to keep the database as it is if the one test fails.

----will add more later

Thanks,
Manjula.

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