Commit ba53dc35 authored by unknown's avatar unknown

Documentation changes to MyTAP.


unittest/README.txt:
  Adding reference to generated documentation
unittest/mytap/Doxyfile:
  Some configuration changes to make Doxygen generate better documentation.
unittest/mytap/tap.c:
  Adding documentation and tags
unittest/mytap/tap.h:
  Adding tags to provide document-internal references.
parent 207202aa
......@@ -37,3 +37,12 @@ directory and add the following to the Makefile.am in that directory
Note, it's important to have "-t" at the end of the filename, otherwise the
test won't be executed by 'make test' !
Documentation
-------------
The generated documentation is temporarily placed at:
http://www.kindahl.net/mytap/doc/
I will move it to a better place once I figure out where and how.
......@@ -432,7 +432,7 @@ FILE_PATTERNS =
# subdirectories should be searched for input files as well. Possible
# values are YES and NO. If left blank NO is used.
RECURSIVE = YES
RECURSIVE = NO
# The EXCLUDE tag can be used to specify files and/or directories that
# should excluded from the INPUT source files. This way you can easily
......@@ -457,14 +457,14 @@ EXCLUDE_PATTERNS =
# directories that contain example code fragments that are included (see
# the \include command).
EXAMPLE_PATH =
EXAMPLE_PATH = e
# If the value of the EXAMPLE_PATH tag contains directories, you can use the
# EXAMPLE_PATTERNS tag to specify one or more wildcard pattern (like *.cpp
# and *.h) to filter out the source-files in the directories. If left
# blank all files are included.
EXAMPLE_PATTERNS =
EXAMPLE_PATTERNS = *.c
# If the EXAMPLE_RECURSIVE tag is set to YES then subdirectories will be
# searched for input files to be used with the \include or \dontinclude
......@@ -926,7 +926,7 @@ MACRO_EXPANSION = YES
# then the macro expansion is limited to the macros specified with the
# PREDEFINED and EXPAND_AS_PREDEFINED tags.
EXPAND_ONLY_PREDEF = NO
EXPAND_ONLY_PREDEF = YES
# If the SEARCH_INCLUDES tag is set to YES (the default) the includes files
# in the INCLUDE_PATH (see below) will be search if a #include is found.
......@@ -939,33 +939,34 @@ SEARCH_INCLUDES = YES
INCLUDE_PATH =
# You can use the INCLUDE_FILE_PATTERNS tag to specify one or more wildcard
# patterns (like *.h and *.hpp) to filter out the header-files in the
# directories. If left blank, the patterns specified with FILE_PATTERNS will
# be used.
# You can use the INCLUDE_FILE_PATTERNS tag to specify one or more
# wildcard patterns (like *.h and *.hpp) to filter out the
# header-files in the directories. If left blank, the patterns
# specified with FILE_PATTERNS will be used.
INCLUDE_FILE_PATTERNS =
# The PREDEFINED tag can be used to specify one or more macro names that
# are defined before the preprocessor is started (similar to the -D option of
# gcc). The argument of the tag is a list of macros of the form: name
# or name=definition (no spaces). If the definition and the = are
# omitted =1 is assumed.
# The PREDEFINED tag can be used to specify one or more macro names
# that are defined before the preprocessor is started (similar to the
# -D option of gcc). The argument of the tag is a list of macros of
# the form: name or name=definition (no spaces). If the definition and
# the = are omitted =1 is assumed.
PREDEFINED =
# If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then
# this tag can be used to specify a list of macro names that should be expanded.
# The macro definition that is found in the sources will be used.
# Use the PREDEFINED tag if you want to use a different macro definition.
# If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES
# then this tag can be used to specify a list of macro names that
# should be expanded. The macro definition that is found in the
# sources will be used. Use the PREDEFINED tag if you want to use a
# different macro definition.
EXPAND_AS_DEFINED =
EXPAND_AS_DEFINED = __attribute__
# If the SKIP_FUNCTION_MACROS tag is set to YES (the default) then
# doxygen's preprocessor will remove all function-like macros that are alone
# on a line, have an all uppercase name, and do not end with a semicolon. Such
# function macros are typically used for boiler-plate code, and will confuse the
# parser if not removed.
# doxygen's preprocessor will remove all function-like macros that are
# alone on a line, have an all uppercase name, and do not end with a
# semicolon. Such function macros are typically used for boiler-plate
# code, and will confuse the parser if not removed.
SKIP_FUNCTION_MACROS = YES
......
......@@ -25,12 +25,18 @@
#include <stdio.h>
#include <string.h>
/**
@defgroup MyTAP_Internal MyTAP Internals
Internal functions and data structures for the MyTAP implementation.
*/
/**
Test data structure.
Data structure containing all information about the test suite.
@ingroup MyTAP
@ingroup MyTAP_Internal
*/
static TEST_DATA g_test = { 0, 0, 0, "" };
......@@ -38,6 +44,8 @@ static TEST_DATA g_test = { 0, 0, 0, "" };
Output stream for test report message.
The macro is just a temporary solution.
@ingroup MyTAP_Internal
*/
#define tapout stdout
......@@ -47,7 +55,7 @@ static TEST_DATA g_test = { 0, 0, 0, "" };
To emit the directive, use the emit_dir() function
@ingroup MyTAP
@ingroup MyTAP_Internal
@see emit_dir
......@@ -56,7 +64,7 @@ static TEST_DATA g_test = { 0, 0, 0, "" };
@param ap Vararg list for the description string above.
*/
static void
emit_tap(int pass, char const *fmt, va_list ap)
vemit_tap(int pass, char const *fmt, va_list ap)
{
fprintf(tapout, "%sok %d%s",
pass ? "" : "not ",
......@@ -77,18 +85,22 @@ emit_tap(int pass, char const *fmt, va_list ap)
not ok 2 # todo some text explaining what remains
@endcode
@ingroup MyTAP_Internal
@param dir Directive as a string
@param exp Explanation string
@param why Explanation string
*/
static void
emit_dir(const char *dir, const char *exp)
emit_dir(const char *dir, const char *why)
{
fprintf(tapout, " # %s %s", dir, exp);
fprintf(tapout, " # %s %s", dir, why);
}
/**
Emit a newline to the TAP output stream.
@ingroup MyTAP_Internal
*/
static void
emit_endl()
......@@ -96,6 +108,7 @@ emit_endl()
fprintf(tapout, "\n");
}
void
diag(char const *fmt, ...)
{
......@@ -144,7 +157,7 @@ ok(int const pass, char const *fmt, ...)
if (!pass && *g_test.todo == '\0')
++g_test.failed;
emit_tap(pass, fmt, ap);
vemit_tap(pass, fmt, ap);
va_end(ap);
if (*g_test.todo != '\0')
emit_dir("todo", g_test.todo);
......@@ -169,7 +182,7 @@ skip(int how_many, char const *const fmt, ...)
while (how_many-- > 0)
{
va_list ap;
emit_tap(1, NULL, ap);
vemit_tap(1, NULL, ap);
emit_dir("skip", reason);
emit_endl();
}
......@@ -262,7 +275,7 @@ int exit_status() {
@section UnitTest Writing unit tests
The purpose of writing unit tests is to use them to drive component
development towards a solution that the tests. This means that the
development towards a solution that passes the tests. This means that the
unit tests has to be as complete as possible, testing at least:
- Normal input
......@@ -271,29 +284,240 @@ int exit_status() {
- Error handling
- Bad environment
We will go over each case and explain it in more detail.
@subsection NormalSubSec Normal input
This is to test that the component have the expected behaviour.
This is just plain simple: test that it works. For example, test
that you can unpack what you packed, adding gives the sum, pincing
the duck makes it quack.
This is what everybody does when they write tests.
@subsection BorderlineTests Borderline cases
If you have a size anywhere for your component, does it work for
size 1? Size 0? Sizes close to <code>UINT_MAX</code>?
It might not be sensible to have a size 0, so in this case it is
not a borderline case, but rather a faulty input (see @ref
FaultyInputTests).
@subsection FaultyInputTests Faulty input
Does your bitmap handle 0 bits size? Well, it might not be designed
for it, but is should <em>not</em> crash the application, but
rather produce an error. This is called defensive programming.
Unfortunately, adding checks for values that should just not be
entered at all is not always practical: the checks cost cycles and
might cost more than it's worth. For example, some functions are
designed so that you may not give it a null pointer. In those
cases it's not sensible to pass it <code>NULL</code> just to see it
crash.
@subsection NormalSSec Normal input
Since every experienced programmer add an <code>assert()</code> to
ensure that you get a proper failure for the debug builds when a
null pointer passed (you add asserts too, right?), you will in this
case instead have a controlled (early) crash in the debug build.
@subsection BorderlineSSec Borderline cases
@subsection FaultySSec Faulty input
@subsection ErrorHandlingTests Error handling
@subsection ErrorSSec Error handling
This is testing that the errors your component is designed to give
actually are produced. For example, testing that trying to open a
non-existing file produces a sensible error code.
@subsection EnvironmentSSec Environment
@subsection BadEnvironmentTests Environment
Sometimes, modules has to behave well even when the environment
fails to work correctly. Typical examples are: out of dynamic
memory, disk is full,
fails to work correctly. Typical examples are when the computer is
out of dynamic memory or when the disk is full. You can emulate
this by replacing, e.g., <code>malloc()</code> with your own
version that will work for a while, but then fail. Some things are
worth to keep in mind here:
- Make sure to make the function fail deterministically, so that
you really can repeat the test.
- Make sure that it doesn't just fail immediately. The unit might
have checks for the first case, but might actually fail some time
in the near future.
@section UnitTestSec How to structure a unit test
@section UnitTest How to structure a unit test
In this section we will give some advice on how to structure the
unit tests to make the development run smoothly.
unit tests to make the development run smoothly. The basic
structure of a test is:
- Plan
- Test
- Report
@subsection TestPlanning Plan the test
Planning the test means telling how many tests there are. In the
event that one of the tests causes a crash, it is then possible to
see that there are fewer tests than expected, and print a proper
error message.
To plan a test, use the @c plan() function in the following manner:
@code
int main(int argc, char *argv[])
{
plan(5);
.
.
.
}
@endcode
If you don't call the @c plan() function, the number of tests
executed will be printed at the end. This is intended to be used
while developing the unit and you are constantly adding tests. It
is not indented to be used after the unit has been released.
@subsection TestRunning Execute the test
@subsection PieceSec Test each piece separately
To report the status of a test, the @c ok() function is used in the
following manner:
@code
int main(int argc, char *argv[])
{
plan(5);
ok(ducks == paddling_ducks,
"%d ducks did not paddle", ducks - paddling_ducks);
.
.
.
}
@endcode
This will print a test result line on the standard output in TAP
format, which allows TAP handling frameworks (like Test::Harness)
to parse the status of the test.
@subsection TestReport Report the result of the test
At the end, a complete test report should be written, with some
statistics. If the test returns EXIT_SUCCESS, all tests were
successfull, otherwise at least one test failed.
To get a TAP complient output and exit status, report the exit
status in the following manner:
@code
int main(int argc, char *argv[])
{
plan(5);
ok(ducks == paddling_ducks,
"%d ducks did not paddle", ducks - paddling_ducks);
.
.
.
return exit_status();
}
@endcode
@section DontDoThis Ways to not do unit testing
In this section, we'll go through some quite common ways to write
tests that are <em>not</em> a good idea.
@subsection BreadthFirstTests Doing breadth-first testing
If you're writing a library with several functions, don't test all
functions using size 1, then all functions using size 2, etc. If a
test for size 42 fails, you have no easy way of tracking down why
it failed.
It is better to concentrate on getting one function to work at a
time, which means that you test each function for all sizes that
you think is reasonable. Then you continue with the next function,
doing the same. This is usually also the way that a library is
developed (one function at a time) so stick to testing that is
appropriate for now the unit is developed.
@subsection JustToBeSafeTest Writing unnecessarily large tests
Don't write tests that use parameters in the range 1-1024 unless
you have a very good reason to belive that the component will
succeed for 562 but fail for 564 (the numbers picked are just
examples).
It is very common to write extensive tests "just to be safe."
Having a test suite with a lot of values might give you a warm
fuzzy feeling, but it doesn't really help you find the bugs. Good
tests fail; seriously, if you write a test that you expect to
succeed, you don't need to write it. If you think that it
<em>might</em> fail, <em>then</em> you should write it.
Don't take this as an excuse to avoid writing any tests at all
"since I make no mistakes" (when it comes to this, there are two
kinds of people: those who admit they make mistakes, and those who
don't); rather, this means that there is no reason to test that
using a buffer with size 100 works when you have a test for buffer
size 96.
The drawback is that the test suite takes longer to run, for little
or no benefit. It is acceptable to do a exhaustive test if it
doesn't take too long to run and it is quite common to do an
exhaustive test of a function for a small set of values.
Use your judgment to decide what is excessive: your milage may
vary.
*/
/**
@example simple.t.c
This is an simple example of how to write a test using the
library. The output of this program is:
@code
1..1
# Testing basic functions
ok 1 - Testing gcs()
@endcode
The basic structure is: plan the number of test points using the
plan() function, perform the test and write out the result of each
test point using the ok() function, print out a diagnostics message
using diag(), and report the result of the test by calling the
exit_status() function. Observe that this test does excessive
testing (see @ref JustToBeSafeTest), but the test point doesn't
take very long time.
*/
/**
@example todo.t.c
This example demonstrates how to use the <code>todo_start()</code>
and <code>todo_end()</code> function to mark a sequence of tests to
be done. Observe that the tests are assumed to fail: if any test
succeeds, it is considered a "bonus".
*/
/**
@example skip.t.c
This is an example of how the <code>SKIP_BLOCK_IF</code> can be
used to skip a predetermined number of tests. Observe that the
macro actually skips the following statement, but it's not sensible
to use anything than a block.
*/
/**
@example skip_all.t.c
Don't test all functions using size 1, then all functions using
size 2, etc.
Sometimes, you skip an entire test because it's testing a feature
that doesn't exist on the system that you're testing. To skip an
entire test, use the <code>skip_all()</code> function according to
this example.
*/
......@@ -23,16 +23,13 @@
#include "my_global.h"
/*
@defgroup MyTAP MySQL support for performing unit tests according to TAP.
*/
#define NO_PLAN (0)
/**
Data about test plan.
@ingroup MyTAP_Internal
@internal We are using the "typedef struct X { ... } X" idiom to
create class/struct X both in C and C++.
*/
......@@ -59,6 +56,14 @@ typedef struct TEST_DATA {
extern "C" {
#endif
/**
@defgroup MyTAP_API MyTAP API
MySQL support for performing unit tests according to TAP.
@{
*/
/**
Set number of tests that is planned to execute.
......@@ -93,11 +98,14 @@ void ok(int pass, char const *fmt, ...)
/**
Skip a determined number of tests.
Function to print that <em>how_many</em> tests have been
skipped. The reason is printed for each skipped test. Observe
that this function does not do the actual skipping for you, it just
prints information that tests have been skipped. It shall be used
in the following manner:
Function to print that <em>how_many</em> tests have been skipped.
The reason is printed for each skipped test. Observe that this
function does not do the actual skipping for you, it just prints
information that tests have been skipped. This function is not
usually used, but rather the macro @c SKIP_BLOCK_IF, which does the
skipping for you.
It shall be used in the following manner:
@code
if (ducks == 0) {
......@@ -130,10 +138,9 @@ void skip(int how_many, char const *reason, ...)
for (i = 0 ; i < 2 ; ++i)
ok(duck[i] == paddling, "is duck %d paddling?", i);
}
@endcode
@see skip
@endcode
*/
#define SKIP_BLOCK_IF(SKIP_IF_TRUE, COUNT, REASON) \
if (SKIP_IF_TRUE) skip((COUNT),(REASON)); else
......@@ -158,8 +165,8 @@ void diag(char const *fmt, ...)
return exit_status();
@endcode
@returns EXIT_SUCCESS if all tests passed, EXIT_FAILURE if one or
more tests failed.
@returns @c EXIT_SUCCESS if all tests passed, @c EXIT_FAILURE if
one or more tests failed.
*/
int exit_status(void);
......@@ -202,6 +209,8 @@ void todo_start(char const *message, ...)
*/
void todo_end();
/** @} */
#ifdef __cplusplus
}
#endif
......
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