* Testing
Testing is an important part of the Mono project: every one of its
three major components has a test suite tailored for its needs. This
is very helpful, because in the course of developing the software it
is very common to introduce bugs in existing code. A test suite
helps us fix the bugs as soon as they are introduced.
There are various kinds of tests in Mono:
* Class Library Tests
All classes in Mono libraries should have comprehensive unit test
suites to go with them. Unit testing is a software engineering
methodology that makes it easier to build correct code. Every
method in every class should have a set of tests to verify
that they work correctly. Mono also needs a testing framework
to make it easy to write and run lots of tests.
In some classes, we might also provide standalone tests because of
some reasons such as too huge testcases, another downloading and so on.
(For example, managed XSLT has standalone test which downloads and
expands some megabytes of OASIS test suite.)
Here I list them up as long as I know. If you are going to add another
standalone tests, please add one line here. It is also recommended that
you add some notes on how to build and run tests.
* Mono.Data/test/
* System.Data/Test, and some individual ADO.NET libraries:
there are some standalone tests. See the bottom of
ADO.NET page for detail.
* System.Web/Test/TestMonoWeb : see README
* System.Web.Services/Test/standalone : see README
* System.Windows.Forms/SWFTest/
* System.XML/Test/System.Xml/standalone_tests : see README
* System.XML/Test/System.Xml.Schema/standalone_tests : see README
* System.XML/System.Xml.Serialization/standalone_tests/
* System.XML/Test/System.Xml.Xsl/standalone_tests : see README
* Commons.Xml.Relaxng/Test/standalone_tests : see README
** Getting started
If you are new to writing NUnit tests, there is a template you may use
to help get started. The file is:
mcs/class/doc/TemplateTest.cs
Save a copy of this file in the appropriate test subdirecty
(see below), and replace all the {text} markers with
appropriate code. Comments in the template are there to guide
you. You should also look at existing tests to see how other
people have written them.
mcs/class/corlib/Test/System.Collections/CollectionBaseTest.cs
is a small one that might help.
The directory that will contain your new file depends on the
assembly/namespace of the class for which you are creating the
tests. Under mcs/class there is a directory for each
assembly. In each assembly there is a Test directory,
e.g. mcs/class/corlib/Test. In the Test directory there are
sub-directories for each namespace in the assembly,
e.g. mcs/class/corlib/Test/Sytem. Put your new test file in
the appropriate sub-directory under Test for the class you are
testing.
Once all of that is done, you can do a 'make test' from the top mcs
directory. Your test class needs also to be listed in the
.sources file at the top of the Test directory.
* Tips on writing Unit tests.
You should look at the NUnit documentation,
as it is a fantastic product, and includes fantastic documentation,
but here are some tips for those of you who are already reading
this web page.
** Provide an unique error message for Assert()
Include an unique message for each Assert() so that when the assert
fails, it is trivial to locate it in the source. Otherwise, it may be
difficult to determine which part of the test is failing. A good way
to ensure unique messages is to use something like #A01, #A02 etc.
Ok:
AssertEquals("array match", compare[0], i1[0]);
AssertEquals("array match", compare[1], i1[1]);
AssertEquals("array match", compare[2], i1[2]);
AssertEquals("array match", compare[3], i1[3]);
Excellent:
AssertEquals("#A01", compare[0], i1[0]);
AssertEquals("#A02", compare[1], i1[1]);
AssertEquals("#A03", compare[2], i1[2]);
AssertEquals("#A04", compare[3], i1[3]);
Once you used such a number in an Assert(), don't change it later on -
people might use it it identify the test in bug reports or in mailing
lists.
** Use AssertEquals() to compare things, not Assert().
Do not compare two values with Assert() - if the test fails,
people have no idea what went wrong while AssertEquals()
reports the failed value.
Ok:
Assert ("A01", myTicks[0] == t1.Ticks);
Excellent:
AssertEquals ("A01", myTicks[0], t1.Ticks);
** Test your test with the Microsoft runtime
If possible, try to run your testsuite with the Microsoft runtime on
.NET on Windows and make sure all tests in it pass. This is especially
important if you're writing a totally new testcase - without this
check you can never be sure that your testcase contains no bugs ....
Don't worry if you're writing your test on Linux, other people can
test it for you on Windows.
Sometimes you may discover that a test doesn't show the expected
result when run with the Microsoft runtime - either because there is a
bug in their runtime or something is misleading or wrong in their
documentation. In this case, please put a detailed description of the
problem to mcs/class/doc/API-notes and do also report it to the
mailing list - we'll forward this to the
Microsoft people from time to time to help them fix their documentation
and runtime.
** Unit tests.
Why do unit testing? It becomes simple to run automated tests
for the whole library. Unit tests are a safety net - you can
change part of the code and verify that you haven't broken
anything. Ideally, tests are written before the actual library
code itself. And every time a bug is discovered, a test should
be written to demonstrate the bug and its fix. Then, if
you ever reintroduce the bug, you will know immediately. For
more info, read
JUnit Test Infected: Programmers Love Writing Tests.
** Getting Started
We welcome all contributions to the Class Libary Test Suite.
There is information to help you get started in CVS at
mcs/class/doc/NUnitGuidelines. Once you have written your test, please
post it to mono-list.
Someone will make sure to add the file or apply the patch as
appropriate. If you plan to be an on-going contributor and
would like to get cvs account, email miguel.
Normally, after you send a couple of well-written new files
and/or patches to the list, you will be given cvs access.
* Compiler tests
Mono ships with three compilers: C#, VB.NET and JScript. The
tests are ran by running the makefile target `make
run-test-local' in the appropriate directory.
The C# compilation tests live in mcs/tests, and the C# error
tests live in mcs/errors.
The VB.NET compilation tests live in mcs/btests.
* Runtime Tests
These tests verify the virtual machine, to run these tests, do:
cd mono/mono/tests
make test
* ASP.NET tests
XSP, the Mono ASP.NET server has tests for ASP.NET pages. It uses
NUnitAsp. Right now
it only has standalone tests, ie., tests that do not need their own
global.asax or web.config files.
If you want to run them, get the xsp CVS module and install it. Then:
cd xsp/nunit-tests
make
cd standalone
xsp
And from another terminal:
cd xsp/nunit-tests/standalone
nunit-console standalone-tests.dll
* Web Services tests
The Test directory for the System.Web.Services assembly contains a
standalone test suite for testing web services. It tests:
- Proxy generation using the wsdl tool
- Access to web services using the generated client proxies
- Execution of web services in the server
This suite not only tests web services running on XSP, but it can also test
services running on other platforms and that are available in internet. This
will help track down interoperability issues.
To build the test suite, just run:
cd mcs/class/System.Web.Services/Test/standalone
xsp --root server
And from another terminal:
cd mcs/class/System.Web.Services/Test/standalone
make
nunit-console testclient.dll
This will download the wsdl documents, generate the proxies, build a dll with
the proxies, and build the nunit tests. Then you can use nunit-console or
gnunit to run the tests (the nunit dll is testclient.dll).
Read the README file in mcs/class/System.Web.Services/Test/standalone for
more info.