15.2.1 Scripts-based Testsuites

If the special variable TESTS is defined, its value is taken to be a list of programs or scripts to run in order to do the testing. Under the appropriate circumstances, it’s possible for TESTS to list also data files to be passed to one or more test scripts defined by different means (the so-called “log compilers”, see Parallel Test Harness).

Test scripts can be executed serially or concurrently. Automake supports both these kinds of test execution, with the parallel test harness being the default. The concurrent test harness relies on the concurrence capabilities (if any) offered by the underlying make implementation, and can thus only be as good as those are.

By default, only the exit statuses of the test scripts are considered when determining the testsuite outcome. But Automake allows also the use of more complex test protocols, either standard (see Using the TAP test protocol) or custom (see Custom Test Drivers). Note that you can’t enable such protocols when the serial harness is used, though. In the rest of this section we are going to concentrate mostly on protocol-less tests, since we cover test protocols in a later section (again, see Custom Test Drivers).

When no test protocol is in use, an exit status of 0 from a test script will denote a success, an exit status of 77 a skipped test, an exit status of 99 an hard error, and any other exit status will denote a failure.

You may define the variable XFAIL_TESTS to a list of tests (usually a subset of TESTS) that are expected to fail; this will effectively reverse the result of those tests (with the provision that skips and hard errors remain untouched). You may also instruct the testsuite harness to treat hard errors like simple failures, by defining the DISABLE_HARD_ERRORS make variable to a nonempty value.

Note however that, for tests based on more complex test protocols, the exact effects of XFAIL_TESTS and DISABLE_HARD_ERRORS might change, or they might even have no effect at all (for example, in tests using TAP, there is no way to disable hard errors, and the DISABLE_HARD_ERRORS variable has no effect on them).

The result of each test case run by the scripts in TESTS will be printed on standard output, along with the test name. For test protocols that allow more test cases per test script (such as TAP), a number, identifier and/or brief description specific for the single test case is expected to be printed in addition to the name of the test script. The possible results (whose meanings should be clear from the previous Generalities about Testing) are PASS, FAIL, SKIP, XFAIL, XPASS and ERROR. Here is an example of output from an hypothetical testsuite that uses both plain and TAP tests:

PASS: foo.sh
PASS: zardoz.tap 1 - Daemon started
PASS: zardoz.tap 2 - Daemon responding
SKIP: zardoz.tap 3 - Daemon uses /proc # SKIP /proc is not mounted
PASS: zardoz.tap 4 - Daemon stopped
SKIP: bar.sh
PASS: mu.tap 1
XFAIL: mu.tap 2 # TODO frobnication not yet implemented

A testsuite summary (expected to report at least the number of run, skipped and failed tests) will be printed at the end of the testsuite run.

If the standard output is connected to a capable terminal, then the test results and the summary are colored appropriately. The developer and the user can disable colored output by setting the make variable ‘AM_COLOR_TESTS=no’; the user can in addition force colored output even without a connecting terminal with ‘AM_COLOR_TESTS=always’. It’s also worth noting that some make implementations, when used in parallel mode, have slightly different semantics (see Parallel make in The Autoconf Manual), which can break the automatic detection of a connection to a capable terminal. If this is the case, the user will have to resort to the use of ‘AM_COLOR_TESTS=always’ in order to have the testsuite output colorized.

Test programs that need data files should look for them in srcdir (which is both a make variable and an environment variable made available to the tests), so that they work when building in a separate directory (see Build Directories in The Autoconf Manual), and in particular for the distcheck rule (see Checking the Distribution).

The AM_TESTS_ENVIRONMENT and TESTS_ENVIRONMENT variables can be used to run initialization code and set environment variables for the test scripts. The former variable is developer-reserved, and can be defined in the Makefile.am, while the latter is reserved for the user, which can employ it to extend or override the settings in the former; for this to work portably, however, the contents of a non-empty AM_TESTS_ENVIRONMENT must be terminated by a semicolon.

The AM_TESTS_FD_REDIRECT variable can be used to define file descriptor redirections for the test scripts. One might think that AM_TESTS_ENVIRONMENT could be used for this purpose, but experience has shown that doing so portably is practically impossible. The main hurdle is constituted by Korn shells, which usually set the close-on-exec flag on file descriptors opened with the exec builtin, thus rendering an idiom like AM_TESTS_ENVIRONMENT = exec 9>&2; ineffectual. This issue also affects some Bourne shells, such as the HP-UX’s /bin/sh,

AM_TESTS_ENVIRONMENT = \
## Some environment initializations are kept in a separate shell
## file 'tests-env.sh', which can make it easier to also run tests
## from the command line.
  . $(srcdir)/tests-env.sh; \
## On Solaris, prefer more POSIX-compliant versions of the standard
## tools by default.
  if test -d /usr/xpg4/bin; then \
    PATH=/usr/xpg4/bin:$$PATH; export PATH; \
  fi;
## With this, the test scripts will be able to print diagnostic
## messages to the original standard error stream, even if the test
## driver redirects the stderr of the test scripts to a log file
## before executing them.
AM_TESTS_FD_REDIRECT = 9>&2

Note however that AM_TESTS_ENVIRONMENT is, for historical and implementation reasons, not supported by the serial harness (see Older (and discouraged) serial test harness).

Automake ensures that each file listed in TESTS is built before it is run; you can list both source and derived programs (or scripts) in TESTS; the generated rule will look both in srcdir and .. For instance, you might want to run a C program as a test. To do this you would list its name in TESTS and also in check_PROGRAMS, and then specify it as you would any other program.

Programs listed in check_PROGRAMS (and check_LIBRARIES, check_LTLIBRARIES...) are only built during make check, not during make all. You should list there any program needed by your tests that does not need to be built by make all. Note that check_PROGRAMS are not automatically added to TESTS because check_PROGRAMS usually lists programs used by the tests, not the tests themselves. Of course you can set TESTS = $(check_PROGRAMS) if all your programs are test cases.