The curl Test Suite

Running

See the "Requires to run" section for prerequisites.

In the root of the curl repository:

./configure && make && make test

To run a specific set of tests (e.g. 303 and 410):

make test TFLAGS="303 410"

To run the tests faster, pass the -j (parallelism) flag:

make test TFLAGS="-j10"

"make test" builds the test suite support code and invokes the 'runtests.pl' perl script to run all the tests. The value of TFLAGS is passed directly to 'runtests.pl'.

When you run tests via make, the flags -a and -s are passed, meaning to continue running tests even after one fails, and to emit short output.

If you would like to not use those flags, you can run 'runtests.pl' directly. You must chdir into the tests directory, then you can run it like so:

./runtests.pl 303 410

You must have run make test at least once first to build the support code.

To see what flags are available for runtests.pl, and what output it emits, run:

man ./tests/runtests.1

After a test fails, examine the tests/log directory for stdout, stderr, and output from the servers used in the test.

Requires to run

• perl (and a Unix-style shell)
• python (and a Unix-style shell, for SMB and TELNET tests)
• python-impacket (for SMB tests)
• diff (when a test fails, a diff is shown)
• stunnel (for HTTPS and FTPS tests)
• OpenSSH or SunSSH (for SCP and SFTP tests)
• nghttpx (for HTTP/2 and HTTP/3 tests)
• An available en_US.UTF-8 locale

Installation of impacket

The Python-based test servers support Python 3.

Please install python-impacket in the correct Python environment. You can use pip or your OS' package manager to install 'impacket'.

On Debian/Ubuntu the package name is 'python3-impacket'

On FreeBSD the package name is 'py311-impacket'

On any system where pip is available: 'python3 -m pip install impacket'

You may also need to manually install the Python package 'six' as that may be a missing requirement for impacket.

Event-based

If curl is built with Debug enabled (see below), then the runtests.pl script offers a -e option that makes it perform event-based. Such tests invokes the curl tool with --test-event, a debug-only option made for this purpose.

Performing event-based means that the curl tool uses the curl_multi_socket_action() API call to drive the transfer(s), instead of the otherwise "normal" functions it would use. This allows us to test drive the socket_action API. Transfers done this way should work exactly the same as with the non-event based API.

To be able to use --test-event together with --parallel, curl requires libuv to be present and enabled in the build: configure --enable-libuv

Port numbers used by test servers

All test servers run on "random" port numbers. All tests should be written to use suitable variables instead of fixed port numbers so that test cases continue to work independent on what port numbers the test servers actually use.

See FILEFORMAT for the port number variables.

Test servers

The test suite runs stand-alone servers on random ports to which it makes requests. For SSL tests, it runs stunnel to handle encryption to the regular servers. For SSH, it runs a standard OpenSSH server.

The listen port numbers for the test servers are picked randomly to allow users to run multiple test cases concurrently and to not collide with other existing services that might listen to ports on the machine.

The HTTP server supports listening on a Unix domain socket, the default location is 'http.sock'.

For HTTP/2 and HTTP/3 testing an installed nghttpx is used. HTTP/3 tests check if nghttpx supports the protocol. To override the nghttpx used, set the environment variable NGHTTPX. The default can also be changed by specifying --with-test-nghttpx=<path> as argument to configure.

Shell startup scripts

Tests which use the ssh test server, SCP/SFTP tests, might be badly influenced by the output of system wide or user specific shell startup scripts, .bashrc, .profile, /etc/csh.cshrc, .login, /etc/bashrc, etc. which output text messages or escape sequences on user login. When these shell startup messages or escape sequences are output they might corrupt the expected stream of data which flows to the sftp-server or from the ssh client which can result in bad test behavior or even prevent the test server from running.

If the test suite ssh or sftp server fails to start up and logs the message 'Received message too long' then you are certainly suffering the unwanted output of a shell startup script. Locate, cleanup or adjust the shell script.

Memory test

The test script checks that all allocated memory is freed properly IF curl has been built with the CURLDEBUG define set. The script automatically detects if that is the case, and it uses the memanalyze.pl script to analyze the memory debugging output.

Also, if you run tests on a machine where valgrind is found, the script uses valgrind to run the test with (unless you use -n) to further verify correctness.

The runtests.pl -t option enables torture testing mode. It runs each test many times and makes each different memory allocation fail on each successive run. This tests the out of memory error handling code to ensure that memory leaks do not occur even in those situations. It can help to compile curl with CPPFLAGS=-DMEMDEBUG_LOG_SYNC when using this option, to ensure that the memory log file is properly written even if curl crashes.

Debug

If a test case fails, you can conveniently get the script to invoke the debugger (gdb) for you with the server running and the same command line parameters that failed. Just invoke runtests.pl <test number> -g and then just type 'run' in the debugger to perform the command through the debugger.

Logs

All logs are generated in the log/ subdirectory (it is emptied first in the runtests.pl script). They remain in there after a test run.

Log Verbosity

A curl build with --enable-debug offers more verbose output in the logs. This applies not only for test cases, but also when running it standalone with curl -v. While a curl debug built is not suitable for production, it is often helpful in tracking down problems.

Sometimes, one needs detailed logging of operations, but does not want to drown in output. The newly introduced connection filters allows one to dynamically increase log verbosity for a particular filter type. Example:

CURL_DEBUG=ssl curl -v https://curl.se

makes the ssl connection filter log more details. One may do that for every filter type and also use a combination of names, separated by , or space.

CURL_DEBUG=ssl,http/2 curl -v https://curl.se

The order of filter type names is not relevant. Names used here are case insensitive. Note that these names are implementation internals and subject to change.

Some, likely stable names are tcp, ssl, http/2. For a current list, one may search the sources for struct Curl_cftype definitions and find the names there. Also, some filters are only available with certain build options, of course.

Test input files

All test cases are put in the data/ subdirectory. Each test is stored in the file named according to the test number.

See FILEFORMAT for a description of the test case file format.

Code coverage

gcc provides a tool that can determine the code coverage figures for the test suite. To use it, configure curl with CFLAGS='-fprofile-arcs -ftest-coverage -g -O0'. Make sure you run the normal and torture tests to get more full coverage, i.e. do:

make test
make test-torture

The graphical tool ggcov can be used to browse the source and create coverage reports on *nix hosts:

ggcov -r lib src

The text mode tool gcov may also be used, but it does not handle object files in more than one directory correctly.

Remote testing

The runtests.pl script provides some hooks to allow curl to be tested on a machine where perl can not be run. The test framework in this case runs on a workstation where perl is available, while curl itself is run on a remote system using ssh or some other remote execution method. See the comments at the beginning of runtests.pl for details.

Test case numbering

Test cases used to be numbered by category ranges, but the ranges filled up. Subsets of tests can now be selected by passing keywords to the runtests.pl script via the make TFLAGS variable.

New tests are added by finding a free number in tests/data/Makefile.am.

Write tests

Here's a quick description on writing test cases. We basically have three kinds of tests: the ones that test the curl tool, the ones that build small applications and test libcurl directly and the unit tests that test individual (possibly internal) functions.

test data

Each test has a master file that controls all the test data. What to read, what the protocol exchange should look like, what exit code to expect and what command line arguments to use etc.

These files are tests/data/test[num] where [num] is just a unique identifier described above, and the XML-like file format of them is described in the separate FILEFORMAT document.

curl tests

A test case that runs the curl tool and verifies that it gets the correct data, it sends the correct data, it uses the correct protocol primitives etc.

libcurl tests

The libcurl tests are identical to the curl ones, except that they use a specific and dedicated custom-built program to run instead of "curl". This tool is built from source code placed in tests/libtest and if you want to make a new libcurl test that is where you add your code.

unit tests

Unit tests are placed in tests/unit. There is a tests/unit/README describing the specific set of checks and macros that may be used when writing tests that verify behaviors of specific individual functions.

The unit tests depend on curl being built with debug enabled.