gnupg/tests/openpgp

#                                   Emacs, this is an -*- org -*- file.

* How to run the test suite
From your build directory, run

  obj $ make -C tests/openpgp check

to run all tests or

  obj $ make -C tests/openpgp check TESTS=your-test.scm

to run a specific test (or any number of tests separated by spaces).

If you want to debug a test, add verbose=1 to see messages printed by
spawned programs to their standard error stream, verbose=2 to see what
programs are executed, or verbose=3 to see even more program output
and exit codes.

** Passing options to the test driver

You can set TESTFLAGS to pass flags to 'run-tests.scm'.  For example,
to speed up the test suite when bisecting, do

  obj $ make -C tests/openpgp check TESTFLAGS=--parallel

See below for the arguments supported by the driver.

** Calling the test driver directly
This is a bit tricky because one needs to manually set some
environment variables.  We should make that easier.  See discussion
below.  From your build directory, do:

  obj $ srcdir=<path to>/tests/openpgp \
        GPGSCM_PATH=<path to>/tests/gpgscm:<path to>/tests/openpgp \
        $(pwd)/tests/gpgscm/gpgscm [gpgscm args] \
        run-tests.scm [test suite runner args]

*** Arguments supported by the test suite runner
The test suite runner supports two modes of operation, '--sequential'
and '--parallel'.  By default the tests are run in sequential order,
each one in a clean environment.

You can specify the tests to run as positional arguments relative to
srcdir (e.g. just 'version.scm').  Note that you do not have to
specify setup.scm and finish.scm, they are executed implicitly.

The test suite runner can be executed in any location that the current
user can write to.  It will create temporary files and directories,
but will in general clean up all of them.
*** Discussion of the various environment variables
**** srcdir
Must be set to the source of the openpgp test suite.  Used to locate
data files.
**** GPGSCM_PATH
Used to locate the Scheme library as well as code used by the test
suite.
**** BIN_PREFIX
The test suite does not hardcode any paths to tools.  If set it is
used to locate the tools to test, otherwise the test suite assumes to
be run from the build directory.
**** MKTDATA and GPG_PRESET_PASSPHRASE
These two tools are not installed by 'make install', hence we need to
explicitly override their position.  In fact, the location of any tool
used by the test suite can be overridden this way.  See defs.scm.
**** argv[0]
run-tests.scm depends on being able to re-exec gpgscm.  It uses
argv[0] for that.  Therefore you must use an absolute path to invoke
gpgscm.
* How to write tests
gpgscm provides a number of functions to aid you in writing tests, as
well as bindings to process management abstractions provided by GnuPG.
For the Scheme environment provided by TinySCHEME, see the TinySCHEME
manual that is included in tests/gpgscm/Manual.txt.

For a quick start, please have a look at various tests that are
already implemented, e.g. 'encrypt.scm'.
** The test framework
The functions info, error, and skip display their first argument and
flush the output buffers.  error and skip will also terminate the
process, signaling that the test failed or should be skipped.

(for-each-p msg proc list) will display msg, and call proc with each
element of list while displaying the progress appropriately.
for-each-p' is similar, but accepts another callback before the 'list'
argument to format each item.  for-each-p can be safely nested, and
the inner progress indicator will be abbreviated using '.'.
** Debugging tests

Say you are working on a new test called 'your-test.scm', you can run
it on its own using

  obj $ make -C tests/openpgp check TESTS=your-test.scm

but something isn't working as expected.  There are several little
gadgets that might help.  The first one is 'trace', a function that
prints the value given to it and evaluates to it.  E.g.

  (trace (+ 2 3))

prints '5' and evaluates to 5.  Also, there is an 'assert' macro that
aborts the execution if its argument does not evaluate to a trueish
value.  Feel free to express invariants with it.

You can also get an interactive repl by dropping

  (interactive-repl (current-environment))

anywhere you like.  Or, if you want to examine the environment from an
operating system shell, use

  (interactive-shell)

** Interfacing with gpg

defs.scm defines several convenience functions.  Say you want to parse
the colon output from gpg, there is gpg-with-colons that splits the
result at newlines and colons, so you can use the result like this:

 (define (fpr some-key)
   (list-ref (assoc "fpr" (gpg-with-colons
			   `(--with-fingerprint
			     --list-secret-keys ,some-key)))
	     9))

Or if you want to count all non-revoked uids for a given key, do

 (define (count-uids-of-secret-key some-key)
   (length (filter (lambda (x) (and (string=? "uid" (car x))
				    (string=? "u" (cadr x))))
		   (gpg-with-colons
		    `(--with-fingerprint
		      --list-secret-keys ,some-key)))))

** Temporary files
(lettmp <bindings> <body>) will create and delete temporary files that
you can use in <body>.  (with-temporary-working-directory <body>) will
create a temporary director, change to that, and clean it up after
executing <body>).

make-temporary-file will create a temporary file.  You can optionally
provide an argument to that function that will serve as tag so you can
distinguish the files for debugging.  remove-temporary-file will
delete a file created using make-temporary-file.

** Monadic transformer and pipe support
Tests often perform sequential transformations on files, or connect
processes using pipes.  To aid you in this, the test framework
provides two monadic data structures.

(Currently, the implementation mashes the 'bind' operation together
with the application of the monad.  Also, there is no 'return'
operation.  I guess all of that could be implemented on top of
call/cc, but it isn't at the moment.)
*** pipe
The pipe monad constructs pipe lines.  It consists of a function
pipe:do that binds the functions together and manages the execution of
the child processes, a family of functions that act as sources, a
function to spawn processes, and a family of functions acting as
sinks.

Sources are pipe:open, pipe:defer, pipe:echo.  To spawn a process use
pipe:spawn, or the convenience function pipe:gpg.  To sink the data
use pipe:splice, or pipe:write-to.

Example:

  (pipe:do
    (pipe:echo "3\n1\n2\n")
    (pipe:spawn '("/usr/bin/sort"))
    (pipe:write-to "sorted" (logior O_WRONLY O_CREAT) #o600))

Caveats: Due to the single-threaded nature of gpgscm you cannot use
both a source and sink that is implemented in Scheme.  pipe:defer and
pipe:echo are executing in gpgscm, and so does pipe:splice.
*** tr
The transformer monad describes sequential file transformations.

There is one source function, tr:open.  To describe a transformation
using some process, use tr:spawn, tr:gpg, or tr:pipe-do.  There are
several sinks, although sink is not quite the right term, because the
data is not consumed, and hence one can use them at any position.  The
"sinks" are tr:write-to, tr:call-with-content, tr:assert-identity, and
tr:assert-weak-identity.

A somewhat contrived example demonstrating many functions is:

  (tr:do
    (tr:pipe-do
      (pipe:echo "3\n1\n2\n")
      (pipe:spawn '("/usr/bin/sort")))
    (tr:write-to "reference")
    (tr:call-with-content
     (lambda (c)
       (echo "currently, c contains" (string-length c) "bytes")))
    (tr:spawn "" '("/usr/bin/gcc" -x c "-E" -o **out** **in**))
    (tr:pipe-do
      (pipe:spawn '("/bin/grep" -v "#")))
    (tr:assert-identity "reference"))

Caveats: As a convenience, gpgscm allows one to specify command line
arguments as Scheme symbols.  Scheme symbols, however, are
case-insensitive, and get converted to lower case.  Therefore, the -E
argument must be given as a string in the example above.  Similarly,
you need to quote numerical values.
** Process management
If you just need to execute a single command, there is (call-with-fds
cmdline infd outfd errfd) which executes cmdline with the given file
descriptors bound to it, and waits for its completion returning the
status code.  There is (call cmdline) which is similar, but calls the
command with a closed stdin, connecting stdout and stderr to stderr if
gpgscm is executed with --verbose.  (call-check cmdline) raises an
exception if the command does not return 0.

(call-popen cmdline input) calls a command, writes input to its stdin,
and returns any output from stdout, or raises an exception containing
stderr on failure.
* Sample messages