path: root/doc/tcltest.n

'\"
'\" Copyright (c) 1990-1994 The Regents of the University of California
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\" Copyright (c) 1998-1999 Scriptics Corporation
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: tcltest.n,v 1.4 1999/07/26 22:50:53 jenn Exp $
'\" 
.so man.macros
.TH "Tcltest" n 8.2 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
Tcltest \- Test harness support code and utilities
.SH SYNOPSIS
\fBpackage require tcltest ?1.0?\fP
.sp
\fB::tcltest::test \fIname desc ?constraint? script expectedAnswer\fR
.sp
\fB::tcltest::cleanupTests \fI?runningMultipleTests?\fR
.sp
\fB::tcltest::getMatchingTestFiles
.sp
\fB::tcltest::makeFile \fIcontents name\fR
.sp
\fB::tcltest::removeFile \fIname\fR
.sp
\fB::tcltest::makeDirectory \fIname\fR
.sp
\fB::tcltest::removeDirectory \fIname\fR
.sp
\fB::tcltest::viewFile \fIname\fR
.sp
\fB::tcltest::normalizeMsg \fImsg\fR
.sp
\fB::tcltest::bytestring \fIstring\fR
.sp
\fB::tcltest::saveState
.sp
\fB::tcltest::restoreState
.sp
\fB::tcltest::threadReap
.BE
.SH DESCRIPTION
.PP
The \fBtcltest\fR package provides the user with utility tools for
writing and running tests in the Tcl test suite.  It can also be used
to create a customized test harness for an extension. 
.PP
The Tcl test suite consists of multiple .test files, each of which
contains multiple test cases.  Each test case consists of a call to
the test command, which specifies the name of  test, a short
description, any constraints that apply to the test case, the script
to be run, and expected results.  See the sections \fI"Tests,"\fR
\fI"Test Constraints,"\fR and \fI"Test Files and How to Run Them"\fR
for more details. 
.PP
It is also possible to add to this test harness to create your own
customized test harness implementation.  For more defails, see the
section \fI"How to Customize the Test Harness"\fR.
.PP
This approach to testing was designed and initially implemented by
Mary Ann May-Pumphrey of Sun Microsystems in the early 1990's.  Many
thanks to her for donating her work back to the public Tcl release.
.SH COMMANDS
.TP
\fB::tcltest::test\fP \fIname desc ?constraints? script expectedAnswer\fR 
The \fB::tcltest::test\fR command is used \fIscript\fR and compare the
its result to \fIexpectedAnswer\fR. It prints an error message if the two do
not match.  If \fB::tcltest::verbose\fR contains "p" or "s", it also prints
out a message if the test passed or was skipped.  The test will be
skipped if it doesn't match the \fB::tcltest::match\fR variable, if it
matches an element in \fB::tcltest::skip\fR, or if one of the elements
of \fIconstraint\fR turns out not to be true.  The 
\fB::tcltest::test\fR command has no defined return values.  See the
\fI"Writing a new test"\fR section for more details on this command.  
.TP
\fB::tcltest::cleanupTests\fP \fI?calledFromAll?\fR
This command should be called at the end of a test file.  It prints
statistics about the tests run and removes files that were created by
\fB::tcltest::makeDirectory\fR and \fB::tcltest::makeFile\fR.  Names
of files and directories created outside of 
\fB::tcltest::makeFile\fR and \fB::tcltest::makeDirectory\fR and
never deleted are printed to \fB::tcltest::outputChannel\fR.  This command
also restores the original shell environment, as described by the ::env
array. \fIcalledFromAll\fR should be specified when
\fB::tcltest::cleanupTests\fR is called from an "all.tcl" file.  Tcl files
files are generally used to run multiple tests.  For more details on how to
run multiple tests, please see the section \fI"Running test files"\fR.
This proc has no defined return value.
.TP
\fB::tcltest::getMatchingTestFiles\fP
This command is used when you want to run multiple test files.  It returns
the list of tests that should be sourced in an 'all.tcl' file.  See the
section \fI"Running test files"\fR for more information.
.TP
\fB::tcltest::makeFile\fP \fIcontents name\fR
Create a file that will be automatically be removed by
\fB::tcltest::cleanupTests\fR at the end of a test file.
This proc has no defined return value.
.TP
\fB::tcltest::removeFile\fP \fIname\fR
Force the file referenced by \fIname\fR to be removed.  This file name
should be relative to \fI::tcltest::temporaryDirectory\fR.  This proc has no
defined return values.
.TP
\fB::tcltest::makeDirectory\fP \fIname\fR
Create a directory named \fIname\fR that will automatically be removed
by \fB::tcltest::cleanupTests\fR at the end of a test file.  This proc
has no defined return value.
.TP
\fB::tcltest::removeDirectory\fP \fIname\fR
Force the directory referenced by \fIname\fR to be removed. This proc
has no defined return value. 
.TP
\fB::tcltest::viewFile\fP \fIfile\fR
Returns the contents of \fIfile\fR.
.TP
\fB::tcltest::normalizeMsg\fP \fImsg\fR
Remove extra newlines from \fImsg\fR.
.TP
\fB::tcltest::bytestring\fP \fIstring\fR
Construct a string that consists of the requested sequence of bytes,
as opposed to a string of properly formed UTF-8 characters using the
value supplied in \fIstring\fR.  This allows the tester to create
denormalized or improperly formed strings to pass to C procedures that
are supposed to accept strings with embedded NULL types and confirm
that a string result has a certain pattern of bytes.
.TP
\fB::tcltest::saveState\fP
\fB::tcltest::restoreState\fP
Save and restore the procedure and global variable names.
A test file might contain calls to \fB::tcltest::saveState\fR and
\fB::tcltest:restoreState\fR if it creates or deletes global variables
or procs. 
.TP
\fB::tcltest::threadReap\fP
\fB::tcltest::threadReap\fR only works if \fItestthread\fR is
defined, generally by compiling tcltest.  If \fItestthread\fR is
defined, \fB::tcltest::threadReap\fR kills all threads except for the
main thread.  It gets the ID of the main thread by calling
\fItestthread names\fR during initialization.  This value is stored in
\fI::tcltest::mainThread\fR. \fB::tcltest::threadReap\fR returns the
number of existing threads at completion.
.SH TESTS
The \fBtest\fR procedure runs a test script and prints an error
message if the script's result does not match the expected result.
The following is the spec for the \fBtest\fR command:
.DS
test <name> <description> ?<constraint>? <script> <expectedAnswer>
.DE
The <name> argument should follow the pattern:
.DS
<target>-<majorNum>.<minorNum>
.DE
For white-box (regression) tests, the target should be the name of the
C function or Tcl procedure being tested.  For black-box tests, the
target should be the name of the feature being tested.  Related tests
should share a major number. 
.PP
The <description> argument is a short textual description of the test,
to help humans understand what it tests.  The name of a Tcl or C
function being tested should be included for regression tests.  If the
test case exists to reproduce a bug, include the bug ID in the
description. 
.PP
The optional <constraints> argument can be list of one or more
keywords or an expression.  If the <constraints> argument consists of
keywords, each of these keywords must be the name of an element in the array
\fI::tcltest::testConstraints\fR.  If any of these elements is false or does
not exist, the test is skipped.  If the <constraints> argument
consists of an expression, that expression is evaluated. If the
expression evaluates to true, then the test is run.  
.PP
Add appropriate constraints (e.g.,
unixOnly) to any tests that should not always be run.  For example, a
test that should only be run on Unix should look like the following:
.PP
.DS
test getAttribute-1.1 {testing file permissions} {unixOnly} {
    lindex [file attributes foo.tcl] 5
} {00644}
.DE
.PP
An example of a test that contains an expression:
.PP
.DS
test unixNotfy-1.1 {Tcl_DeleteFileHandler} {unixOnly && !testthread} {
    catch {vwait x}
    set f [open foo w]
    fileevent $f writable {set x 1}
    vwait x
    close $f
    list [catch {vwait x} msg] $msg
} {1 {can't wait for variable "x":  would wait forever}}
.DE
.PP
See the "Test Constraints" section for a list of built-in
constraints and information on how to add your own constraints.
.PP
The <script> argument contains the script to run to carry out the
test.  It must return a result that can be checked for correctness.
If your script requires that a file be created on the fly, please use
the ::tcltest::makeFile procedure.  If your test requires that a small
file (<50 lines) be checked in, please consider creating the file on
the fly using the ::tcltest::makeFile procedure.  Files created by the
::tcltest::makeFile procedure will automatically be removed by the
::tcltest::cleanupTests call at the end of each test file.
.PP
The <expectedAnswer> argument will be compared against the result of
evaluating the <script> argument.  If they match, the test passes,
otherwise the test fails.
.SH "TCLTEST NAMEPSACE VARIABLES"
The following variables are also defined in the \fBtcltest\fR namespace and
can be used by tests:
.TP
\fB::tcltest::outputChannel\fR
output file ID - defaults to stdout and can be specified using
-outfile on the command line.  
Any test that prints test related output should send
that output to \fI::tcltest::outputChannel\fR rather than letting
that output default to stdout.
.TP
\fB::tcltest::errorChannel\fR
error file ID - defaults to stderr and can be specified using -errfile
on the command line.  
Any test that prints error messages should send
that output to \fI::tcltest::errorChannel\fR rather than printing
directly to stderr.
.TP
\fB::tcltest::mainThread\fR
main thread ID - defaults to 1.  This is the only thread that is not
killed by ::tcltest::threadReap and is set according to the return
value of \fItestthread names\fR at initialization.
.TP
\fB::tcltest::originalEnv\fR
copy of the global "env" array at the beginning of the test run.  This
array is used to restore the "env" array to its original state when
\fI::tcltest::cleanupTests\fR is called.
.TP
\fB::tcltest::workingDirectory\fR
the directory in which the test suite was launched.
.TP
\fB::tcltest::temporaryDirectory\fR
the output directory - defaults to \fI::tcltest::workingDirectory\fR and can be
specified using -tmpdir on the command line.
.TP
\fB::tcltest::testsDirectory\fR
where the tests reside - defaults to \fI::tcltest::workingDirectory\fR
if the script cannot determine where the \fItests\fR directory is
located.  This variable should be explicitly set if tests are being
run from an all.tcl file.
.TP
\fB::tcltest::tcltest\fR
the name of the executable used to invoke the test suite.  
.SH "TEST CONSTRAINTS"
Constraints are used to determine whether a test should be skipped.
Each constraint is stored as an index in the array
\fI::tcltest::testConstraints\fR.  For example, the unixOnly constraint is
defined as the following:
.DS
set ::tcltest::testConstraints(unixOnly) \\
    [string equal $tcl_platform(platform) "unix"]
.DE
If a test is constrained by "unixOnly", then it will only be run if
the value of ::tcltest::testConstraints(unixOnly) is true.  Several
constraints are defined in the \fBtcltest\fR package.  To add file- or
test-specific constraints, you can set the desired index of the
::tcltest::testsConstraints array in your own test file.
.PP
The following is a list of constraints defined in the \fBtcltest\fR package:
.TP
\fIunix\fR
test can only be run on any UNIX platform
.TP
\fIpc\fR
test can only be run on any Windows platform
.TP
\fInt\fR
test can only be run on any Windows NT platform
.TP
\fI95\fR
test can only be run on any Windows 95 platform
.TP
\fI98\fR
test can only be run on any Windows 98 platform
.TP
\fImac\fR
test can only be run on any Mac platform
.TP
\fIunixOrPc\fR
test can only be run on a UNIX or PC platform
.TP
\fImacOrPc\fR
test can only be run on a Mac or PC platform
.TP
\fImacOrUnix\fR
test can only be run on a Mac or UNIX platform
.TP
\fItempNotPc\fR
test can not be run on Windows.  This flag is used to temporarily
disable a test. 
.TP
\fItempNotMac\fR
test can not be run on a Mac.  This flag is used
to temporarily disable a test.
.TP
\fIunixCrash\fR
test crashes if it's run on UNIX.  This flag is used to temporarily
disable a test. 
.TP
\fIpcCrash\fR
test crashes if it's run on Windows.  This flag is used to temporarily
disable a test. 
.TP
\fImacCrash\fR
test crashes if it's run on a Mac.  This flag is used to temporarily
disable a test. 
.TP
\fIemptyTest\fR
test is empty, and so not worth running, but it remains as a
place-holder for a test to be written in the future.  This constraint
always causes tests to be skipped.
.TP
\fIknownBug\fR
test is known to fail and the bug is not yet fixed.  This constraint
always causes tests to be skipped unless the user specifies otherwise.
See the "Introduction" section for more details.
.TP
\fInonPortable\fR
test can only be run in the master Tcl/Tk development environment.
Some tests are inherently non-portable because they depend on things
like word length, file system configuration, window manager, etc.
These tests are only run in the main Tcl development directory where
the configuration is well known.  This constraint always causes tests
to be skipped unless the user specifies otherwise.  
.TP
\fIuserInteraction\fR
test requires interaction from the user.  This constraint always
causes tests to be skipped unless the user specifies otherwise.  
.TP
\fIinteractive\fR
test can only be run in if the interpreter is in interactive mode,
that is the global tcl_interactive variable is set to 1.
.TP
\fInonBlockFiles\fR
test can only be run if platform supports setting files into
nonblocking mode 
.TP
\fIasyncPipeClose\fR
test can only be run if platform supports async flush and async close
on a pipe 
.TP
\fIunixExecs\fR
test can only be run if this machine has commands such as 'cat', 'echo',
etc. available.  
.TP
\fIhasIsoLocale\fR
test can only be run if can switch to an ISO locale
.TP
\fIroot\fR
test can only run if Unix user is root
.TP
\fInotRoot\fR
test can only run if Unix user is not root
.TP
\fIeformat\fR
test can only run if app has a working version of sprintf with respect
to the "e" format of floating-point numbers.
.TP
\fIstdio\fR
test can only be run if the current app can be spawned via a pipe
.SH "RUNNING TEST FILES"
Use the following command to run a test file that uses package
tcltest:
.DS
<shell> <testFile> ?<option> ?<value>?? ...
.DE
Command line options include (tcltest namespace variables that
correspond to each flag are listed at the end of each flag description
in parenthesis): 
.RS
.TP
\fB-help\fR
display usage information.
.TP
\fB-verbose <level>\fR
set the level of verbosity to a substring of "bps".  See the "Test
output" section for an explanation of this option.  (::tcltest::verbose)
.TP
\fB-match <matchList>\fR
only run tests that match one or more of the glob patterns in
<matchList>.  (::tcltest::match)
.TP
\fB-skip <skipList>\fR
do not run tests that match one or more of the glob patterns in
<skipList>.  (::tcltest::skip)
.TP
\fB-file <globPatternList>\fR
only source test files that match any of the items in
<globPatternList> relative to ::tcltest::testsDirectory.  
This option
only makes sense if you are running tests using "all.tcl" as the
<testFile> instead of running single test files directly.
(::tcltest::matchFiles) 
.TP
\fB-notfile <globPatternList>\fR
source files except for those that match any of the items in
<globPatternList> relative to ::tcltest::testsDirectory.
This option
only makes sense if you are running tests using "all.tcl" as the
<testFile> instead of running single test files directly.
(::tcltest::skipFiles) 
.TP
\fB-constraints <list>\fR
tests with any constraints in <list> will not be skipped.  Note that
elements of <list> must exactly match the existing constraints.  This
is useful if you want to make sure that tests with a particular
constraint are run (for example, if the tester wants to run all tests
with the knownBug constraint).
(::tcltest::testConstraints(\fIconstraintName\fR))
.TP
\fB-limitconstraints <bool>\fR
If the argument to this flag is 1, the test harness limits test runs
to those tests that match the constraints listed by the -constraints
flag. Use of this flag requires use of the -constraints flag.  The
default value for this flag is 0 (false).  This is useful if you want
to run \fBonly\fR those tests that match the constraints listed using
the -constraints option.  A tester might want to do this if he were
interested in running only those tests that are constrained to be
unixOnly and no other tests.
(::tcltest::limitConstraints)
.TP
\fB-tmpdir <directoryName>\fR
put any temporary files (created with ::tcltest::makeFile and
::tcltest::makeDirectory) into the named directory.  The default
location is ::tcltest::workingDirectory.  (::tcltest::temporaryDirectory)
.TP
\fB-preservecore <level>\fR
check for core files.  This flag is used to determine how much
checking should be done for core files.  The default value for
\fIlevel\fR is 0.  Levels are defined as:
.RS
.IP 0
No checking - do not check for core files at the end of each test
command, but do check for them whenever ::tcltest::cleanupTests is
called from an all.tcl file. 
.IP 1
Check for core files at the end of each test command and whenever
::tcltest::cleanupTests is called from all.tcl.
.IP 2
Check for core files at the end of all test commands and whenever
::tcltest::cleanupTests is called from all.tcl.  Save any core files
produced in ::tcltest::temporaryDirectory.
.RE
.sp
(::tcltest::preserveCore)
.TP
\fB-debug <debugLevel>\fR
print debug information to stdout.  This is used to debug code in the
test harness.  The default debug level is 0.  Levels are defined as:
.RS
.IP 0
Do not display any debug information.
.IP 1
Display information regarding whether a test is skipped because it
doesn't match any of the tests that were specified using -match or
::tcltest::match (userSpecifiedNonMatch) or matches any of the tests
specified by -skip or ::tcltest::skip (userSpecifiedSkip).  
.IP 2
Display the flag array parsed by the command line processor, the
contents of the ::env array, and all user-defined variables that exist
in the current namespace as they are used.
.IP 3
Display information regarding what individual procs in the test
harness are doing.
.RE
.sp
(::tcltest::debug)
.TP
\fB-outfile <filename>\fR 
print output generated by the tcltest package to the named file.  This
defaults to stdout.  Note that debug output always goes to stdout,
regardless of this flag's setting.  (::tcltest::outputChannel)
.TP
\fB-errfile <filename>\fR
print errors generated by the tcltest package to the named file.  This
defaults to stderr.  (::tcltest::errorChannel)
.RE
.PP
A second way to run tets is to start up a shell, load the
\fBtcltest\fR package, and then source an appropriate test file or use
the test command.  To use the options in interactive mode, set
their corresponding tcltest namespace variables after loading the
package.
.PP
See \fI"Test Constraints"\fR for all built-in constraint names
that can be used in the \fB::tcltest::testConstraints\fR array. 
See \fI"Tcltest namespace variables"\fR for details on other variables
defined in the \fBtcltest\fR namespace.
.PP
A final way to run tests would be to specify which test files to run
within an \fIall.tcl\fR (or otherwise named) file.  This is the
approach used by the Tcl test suite.  This file loads the tcltest
package, sets the location of
the test directory (::tcltest::testsDirectory), determines which test
files to run, sources each of these files, calls
::tcltest::cleanupTests and then exits.
.PP
A more elaborate \fIall.tcl\fR file might do some pre- and
post-processing before sourcing 
each .test file, use separate interpreters for each file, or handle
complex directory structures. 
For an example of an all.tcl file,
please see the "Examples" section of this document.
.SH "TEST OUTPUT"
After all specified test files are run, the number of tests
passed, skipped, and failed is printed to
\fB::tcltest::outputChannel\fR.  Aside from this 
statistical information, output can be controlled on a per-test basis
by the \fB::tcltest::verbose\fR variable.
.PP
\fB::tcltest::verbose\fR can be set to any substring or permutation 
of "bps". In the string "bps", the 'b' stands for a test's "body", 
the 'p' stands for "passed" tests, and the 's' stands for "skipped" 
tests. The default value of \fB::tcltest::verbose\fR is "b".  If 'b'
is present, then the entire body of the test is printed for each
failed test, otherwise only the test's name, desired output, and
actual output, are printed for each failed test.  If 'p' is present,
then a line is printed for each passed test, otherwise no line is
printed for passed tests.  If 's' is present, then a line (containing
the consraints that cause the test to be skipped) is printed for each
skipped test, otherwise no line is printed for skipped tests.
.PP
You can set \fB::tcltest::verbose\fR either interactively (after the
\fBtcltest\fR package has been loaded) or by using the command line
argument \fB-verbose\fR, for example:
.DS
tclsh socket.test -verbose bps
.DE
.SH "CONTENTS OF A TEST FILE"
Test files should begin by loading the \fBtcltest\fR package:
.DS
package require tcltest
namespace import ::tcltest::*
.DE
Test files should end by cleaning up after themselves and calling
\fB::tcltest::cleanupTests\fR.  The \fB::tcltest::cleanupTests\fR
procedure prints statistics about the number of tests that passed,
skipped, and failed, and removes all files that were created using the
\fB::tcltest::makeFile\fR and \fB::tcltest::makeDirectory\fR procedures.
.DS
# Remove files created by these tests
# Change to original working directory
# Unset global arrays
::tcltest::cleanupTests
return
.DE
When naming test files, file names should end with a .test extension.
The names of test files that contain regression (or glass-box) tests
should correspond to the Tcl or C code file that they are testing.
For example, the test file for the C file "tclCmdAH.c" is "cmdAH.test".  
Test files that contain black-box tests should match the pattern "*_bb.test".
.SH "SELECTING TESTS FOR EXECUTION WITHIN A FILE"
.PP
Normally, all the tests in a file are run whenever the file is
sourced.  An individual test will be skipped if one of the following
conditions is met:
.IP [1]
the \fIname\fR of the tests does not match (using glob style matching)
one or more elements in the \fB::tcltest::match\fR variable
.IP [2]
the \fIname\fR of the tests matches (using glob style matching) one or
more elements in the \fB::tcltest::skip\fR variable 
.IP [3]
the \fIconstraints\fR argument to the \fB::tcltest::test\fR call, if
given, contains one or more false elements. 
.PP
You can set \fB::tcltest::match\fR and/or \fB::tcltest::skip\fR
either interactively (after the \fBtcltest\fR package has been
sourced), or by using the command line arguments \fB-match\fR and
\fB-skip\fR, for example: 
.PP
.CS
tclsh info.test -match '*-5.* *-7.*' -skip '*-7.1*'
.CE
.PP
Be sure to use the proper quoting convention so that your shell does
not perform the glob substitution on the match or skip patterns you
specify.
.PP
Predefined constraints (e.g. \fIknownBug\fR and \fInonPortable\fR) can be
overridden either interactively (after the \fBtcltest\fR package has been
sourced) by setting the proper
\fB::tcltest::testConstraints(\fIconstraint\fB)\fR variable 
or by using the \fB-constraints\fR command line option with the name of the
constraint in the argument.  The following example shows how to run
tests that are constrained by the \fIknownBug\fR and \fInonPortable\fR
restrictions:
.PP
.CS
tclsh all.tcl -constraints "knownBug nonPortable"
.CE
.PP
See the \fI"Constraints"\fR package for information about using
built-in constraints and adding new ones.
.SH "HOW TO CUSTOMIZE THE TEST HARNESS"
To create your own custom test harness, create a .tcl file that contains your
namespace.  Within this file, require package \fBtcltest\fR.  Commands
that can be redefined to customize the test harness include:
.TP
\fB::tcltest::PrintUsageInfoHook\fP
print additional usage information specific to your situation.
.TP
\fB::tcltest::processCmdLineArgsFlagHook\fP
tell the test harness about additional flags that you want it to understand.
.TP
\fB::tcltest::processCmdLineArgsHook\fR flags\fP
process the additional flags that you told the harness about in
::tcltest::processCmdLineArgsFlagHook.
.TP
\fB::tcltest::initConstraintsHook\fP
used to add additional built-in constraints to those already defined
by \fBtcltest\fR.  
.TP
\fB::tcltest::cleanupTestsHook\fP
do additional cleanup 
.PP
.PP
To add new flags to your customized test harness, redefine
\fB::tcltest::processCmdLineArgsAddFlagHook\fR to define additional flags to be
parsed and \fB::tcltest::processCmdLineArgsHook\fR to actually process them.
For example:
.DS
proc ::tcltest::processCmdLineArgsAddFlagHook {} {
    return [list -flag1 -flag2]
}

proc ::tcltest::processCmdLineArgsHook {flagArray} {
    array set flag $flagArray

    if {[info exists flag(-flag1)]} {
        # Handle flag1
    }

    if {[info exists flag(-flag2)]} {
        # Handle flag2
    }

    return
}
.DE
You may also want to add usage information for these flags.  This
information would be displayed whenever the user specifies -help.  To
define additional usage information, define your own
::tcltest::PrintUsageInfoHook proc.  Within this proc, you should
print out additional usage information for any flags that you've
implemented. 
.PP
To add new built-in
constraints to the test harness, define your own version of
\fB::tcltest::initConstraintsHook\fR. 
Within your proc, you can add to the \fB::tcltest::testConstraints\fR array.
For example:
.DS
proc ::tcltest::initConstraintsHook {} {
    set ::tcltest::testConstraints(win95Or98) \\
            [expr {$::tcltest::testConstraints(95) || \\
            $::tcltest::testConstraints(98)}]
}
.DE
.PP
Finally, if you want to add additional cleanup code to your harness
you can define your own \fB::tcltest::cleanupTestsHook\fR.  For example:
.DS
proc ::tcltest::cleanupTestsHook {} {
    # Add your cleanup code here
}
.DE
.SH EXAMPLES
.IP [1] 
A simple test file (foo.test)
.DS
if {[lsearch [namespace children] ::tcltest] == -1} {
    package require tcltest
    import namespace ::tcltest::*
}

test foo-1.1 {save 1 in variable name foo} {} {
    set foo 1
} {1}

::tcltest::cleanupTests
return
.DE
.IP [2] 
A simple all.tcl
.DS
if {[lsearch [namespace children] ::tcltest] == -1} {
    package require tcltest
    import namespace ::tcltest::*
}

set ::tcltest::testSingleFile false
set ::tcltest::testsDirectory [file dir [info script]]

foreach file [::tcltest::getMatchingTestFiles] {
    if {[catch {source $file} msg]} {
        puts stdout $msg
    }
}

::tclttest::cleanupTests 1
return
.DE
.IP [3] 
Running a single test
.DS
tclsh foo.test
.DE
.IP [4] 
Running multiple tests
.DS
tclsh all.tcl -file 'foo*.test' -notfile 'foo2.test'
.DE
.SH KEYWORDS
test, test harness, test suite