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DBD-Informix-1.04.PC1
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/ DBD::Informix::TestHarness

NAME

DBD::Informix::TestHarness - Test Harness for DBD::Informix

SYNOPSIS

use DBD::Informix::TestHarness;

DESCRIPTION

This document describes DBD::Informix::TestHarness for DBD::Informix version 1.00 and later. This is pure Perl code which exploits DBI and DBD::Informix to make it easier to write tests. Most notably, it provides a simple mechanism to connect to the user's chosen test database and a uniform set of reporting mechanisms.

Loading DBD::Informix::TestHarness

To use the DBD::Informix::TestHarness software, you need to load the DBI software and then install the Informix driver:

use DBD::Informix::TestHarness;

Connecting to test database

$dbh = &connect_to_test_database({ AutoCommit => 0 });

This gives you a reference to the database connection handle, aka the database handle. If the load fails, your program stops immediately. The functionality available from this handle is documented in the DBD::Informix manual page. This function does not report success when it succeeds because the test scripts for blobs, for example, need to know whether they are working with an OnLine system before reporting how many tests will be run.

This code exploits 3 environment variables:

DBD_INFORMIX_DATABASE
DBD_INFORMIX_USERNAME
DBD_INFORMIX_PASSWORD

The database variable can be simply the name of the database, or it can be 'database@server', or it can be one of the SE notations such as '/opt/dbase' or '//hostname/dbase'. If INFORMIXSERVER is not set, then you had better be on a 5.0x system as otherwise the connection will fail. With 6.00 and above, you can optionally specify a user name and password in the environment. This is horribly insecure -- do not use it for production work. The test scripts do not print the password.

Using connect_noisily

The method connect_noisily is identical to connect_to_test_database.

$dbh = &connect_noisily({ AutoCommit => 0 });

Using connect_quietly

The method connect_quietly does not echo the connection information whereas both connect_noisily and connect_to_test_database do. It is used in a very few special cases where the connection information is of limited interest -- primarily during 'InformixTechSupport -w' or 'ItWorks'.

$dbh = &connect_quietly({ AutoCommit => 0 });

All three connection methods internally use the non-exported connect_controllably method.

Using cleanup_database

If the test needs a clean database to work with, the cleanup_database method removes any tables, views, synonyms (or IUS types) created by the DBD::Informix test suite. These are all identified by the 'dbd_ix_' prefix.

&cleanup_database($dbh);

This is not used in all tests by any stretch of the imagination. In fact, the only test to use it routinely is t/t99clean.t. Whereever possible, tests should use temporary tables.

Using test_for_ius

If the test explicitly requires Informix Universal Server (IUS) or IDS/UDO (Informix Dynamic Server with Universal Data Option -- essentially the product as IUS, but with a longer, more recent, name), then the mechanism to use is:

my ($dbh) = &test_for_ius();

If this returns, then the ESQL/C is capable of handling IUS data types, the database connection worked, and the database server is capable of handling IUS data types.

Using is_shared_memory_connection

You cannot have multiple simultaneous connections if both connections use shared memory connectivity. The multiple connection tests try to determine whether both test databases have shared memory connections. This Unix-centric test provides such a test and allows the tests to report that 'skipping test on this platform'.

if (&is_shared_memory_connection($dbase1)) { ... }

Using stmt_test

Once you have a database connection, you can execute simple statements (those which do not return any data) using &stmt_test():

&stmt_test($dbh, $stmt, $flag, $tag);

The first argument is the database handle. The second is a string containing the statement to be executed. The third is optional and is a boolean. If it is 0, then the statement must execute without causing an error or the test will terminate. If it is set to 1, then the statement may fail and the error will be reported but the test will continue. The fourth argument is an optional string which will be used as a tag before the statement when it is printed. If omitted, it defaults to "Test".

Using stmt_retest

The &stmt_retest() function takes three arguments, which have the same meaning as the first three arguments of &stmt_test():

&stmt_retest($dbh, $stmt, $flag);

It calls:

&stmt_test($dbh, $stmt, 0, "Retest");

Using print_sqlca

The &print_sqlca() function takes a single argument which can be either a statement handle or a database handle and prints out the current values of the SQLCA record.

&print_sqlca($dbh);
&print_sqlca($sth);

Using print_dbinfo

The &print_dbinfo() function takes a single argument which should be a database handle and prints out salient information about the database.

&print_dbinfo($dbh);

Using all_ok

The &all_ok() function can be used at the end of a test script to report that everything was OK. It exits with status 0.

&all_ok();

Using stmt_ok

This routine adds 'ok N' to the end of a line. The N increments automatically each time &stmt_ok() or &stmt_fail() is called. If called with a non-false argument, it prints the contents of DBI::errstr as a warning message too. This routine is used internally by stmt_test() but is also available for your use.

&stmt_ok(0);

Using stmt_fail

This routine adds 'not ok N' to the end of a line, then reports the error message in DBI::errstr, and then dies. The N is incremented automatically, as with &stmt_ok(). This routine is used internally by stmt_test() but is also available for your use. It takes an optional string as an argument, which is printed as well.

&stmt_fail();
&stmt_fail("Reason why test failed");

Using stmt_err

This routines prints a caption (defaulting to 'Error Message') and the contents of DBI::errstr, ensuring that each line is prefixed by "# ". This routine is used internally by the DBD::Informix::TestHarness module, but is also available for your use.

&stmt_err('Warning Message');

Using stmt_note

This routine writes a string (without any newline unless you include it). This routine is used internally by stmt_test() but is also available for your use.

&stmt_note("Some string or other");

Using stmt_comment

This routine writes a string (prepending hash symbols to line and appending a newline if necessary). This routine is used internally by stmt_test() but is also available for your use.

&stmt_comment("Some string or other");

Using date_as_string

This routine takes one to four arguments:

my($date) = &date_as_string($dbh [, $mm [, $dd [, $yyyy]]]);

The first argument is the database handle. The optional second argument is the month number (1..12). The optional third argument is the day number (1..31). The optional fourth argument is the year number (1..9999). If the date values are omitted, then values from 1930-10-20 are substituted. No direct validation is done; if the conversion operations fail, stmt_fail is called. The date value is converted to a string by the database server, and the result returned to the calling function. The string can be enclosed in quotes and will be accepted by the server as a valid date.

Note: the code assumes that the database server supports the '||' string concatenation operator; this is believed to be valid for OnLine 5.00 and above, and DBD::Informix does not support earlier server versions so it is immaterial that it won't work with them.

Using select_some_data

This routine takes four arguments:

&select_some_data($dbh, $nrows, $stmt, $mapnulls);

The first argument is the database handle. The second is the number of rows that should be returned. The third is a string containing the SELECT statement to be executed. The fourth argument is optional but if defined and true, any nulls in the data will be mapped to the string '<<NULL>>'. Otherwise, they will most likely generate a warning when referenced. It routine prints all the data returned with a '#' preceding the first field and two colons separating the fields. It reports OK if the select succeeds and the correct number of rows are returned; it fails otherwise.

Using select_zero_data

This routine takes a database handle and a SELECT statement and invokes &select_some_data with 0 rows expected and null mapping enabled.

&select_zero_data($dbh, $stmt);

Using memory_leak_test

This routine takes a reference to a subroutine, and optionally a nap time in seconds (default 5) and a ps command string (default "ps -lp", suitable for Solaris 2.x and Solaris 7).

Normally, your test script will simply call this routine and exit. The remaining code in the test file will implement a test which shows the memory leak. You should not connect to the test database before invoking memory_leak_test.

use strict;
use DBD::Informix::TestHarness;
&memory_leak_test(\&test_subroutine);
exit;

When it is called, memory_leak_test forks, and the parent process runs the given subroutine with no arguments. The subroutine will do the sequence of database operations which show that there is a memory leak, or that the memory leak is fixed. The child process checks that the parent is still alive, and runs the ps command to determine the size of the process. The output of ps is not parsed, so you have to run the test in a verbose mode to see whether there is a memory leak or not.

&memory_leak_test(\&test_subroutine);
&memory_leak_test(\&test_subroutine, 10, "ps -l | grep");

The ps command string has a process number appended to the end after a space, and should report the size of the given process. Note that the last example is not as reliable as requesting the process status of a specific process number; it will probably show the grep command and the child Perl process, and maybe random other processes.

Using primary_connection

The primary_connection function returns three values, the database name, the username and the password for the primary test connection. This is used internally by the connect_controllably function, and hence by the connect_to_test_database function.

my ($dbase, $user, $pass) = &primary_connection();
my ($dbh) = DBI->connect("dbi:Informix:$dbase", $user, $pass)
                or die "$DBI::errstr\n";

In looking for the three values, it examines the environment variables DBD_INFORMIX_DATABASE, DBD_INFORMIX_USERNAME and DBD_INFORMIX_PASSWORD. If the database is not determined, it looks at the DBI_DBNAME environment variable (which is essentially obsolete as far as DBI is concerned, but which is documented by the esqltest code -- an alternative was to remove support for DBI_DBNAME from esqltest.ec). If DBI_DBNAME is not set, then the default database name is 'stores' with no version suffix. If the username and password are not set, then empty strings are returned.

Using secondary_connection

The secondary_connection function also returns three values, the database name, the username and the password for the secondary test connection. This is used in the multiple connection tests.

my ($dbase, $user, $pass) = &secondary_connection();
my ($dbh) = DBI->connect("dbi:Informix:$dbase", $user, $pass)
                or die "$DBI::errstr\n";

In looking for the three values, it examines the environment variables DBD_INFORMIX_DATABASE2, DBD_INFORMIX_USERNAME2 and DBD_INFORMIX_PASSWORD2. If the database is not determined, it uses the primary_connection method above to specify the values.

Note

All these routines can also be used without parentheses or the &, so that the following is also valid:

select_zero_data $dbh, $stmt;

AUTHOR

At various times:

  • Jonathan Leffler (johnl@informix.com) # obsolete email address

  • Jonathan Leffler (j.leffler@acm.org)

  • Jonathan Leffler (jleffler@informix.com) # obsolete email address

  • Jonathan Leffler (jleffler@us.ibm.com)

SEE ALSO

perl(1), DBD::Informix