How to add a build-time test

Writing a test is good, but it is even more helpful if that test gets executed. We have various automation tools that help make this possible. The first link, though, is the "check" target in a Makefile. If a test is added, that test or its directory needs to be mentioned in a Makefile.in file somewhere so that the build system knows about it.

Standalone executables

To add a test that is written in C or C++ and which is called as a standalone executable, a few things must be done. For standalone executables, if one sets up the right variables, then the rules.mk file will do lots of magic and most of the heavy lifting. A simple example of adding a test is in .

Note that the following variables are supplied by the rules.mk file: CPPSRCS, SIMPLE_PROGRAMS, RUN_TEST_PROGRAM.

1. For now, enclose your test-related code (in the makefile) with ifdef ENABLE_TESTS
2. Run the test program from the "check" target in the makefile. (example to run the TestCookie program)
3. In the test program:
   • If the test fails, exit with a non-zero status and/or print the string "FAIL" to stdout
   • If the test passes, exit with a zero status and don't print the string "FAIL" (bonus points for printing "PASS" :) )

Write the test so that you expect it to pass on all platforms, since if the test fails, the tree will go orange (once we've set this up - see bug 352240 for status).

For example, to add an xpcshell test to a module, do the following:

1. Copy tools/test-harness/xpcshell-simple/example to yourmoduledir/tests_type, where tests_type is something that describes your tests. You can of course use unit or test if you're not feeling creative.
2. In <tt>yourmoduledir/tests_type/Makefile.in</tt> change DEPTH, MODULE, and XPCSHELL_TESTS appropriately:
• DEPTH should be a relative path pointing to <tt>mozilla/</tt>, e.g. if you're in <tt>netwerk/test</tt>, set DEPTH = ../..
• MODULE should be defined to test_yourmodule or just yourmodule -- either will work fine.
• XPCSHELL_TESTS be a list of subdirectories of the current directory which contain xpcshell tests. You can of course just use the one tests_type directory here, but if you want to subdivide your tests by functionality, separate directories is the way to go.
3. Reference the test dir in a parent makefile (<tt>yourmoduledir/Makefile.in</tt>):

   ifdef ENABLE_TESTS
   DIRS  += tests_type
   endif

4. (Optional, but recommended) Add the new makefile to allmakefiles.sh (TODO: need more details about this)
5. Reconfigure (e.g. with <tt>make -f client.mk configure</tt>)
6. make / make check in <tt>yourmodule</tt>