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<sect1 id="xfunc">

<term><varname>REGRESS</varname></term>

<listitem>

<para>

list of regression test cases (without suffix)

list of regression test cases (without suffix), see below

</para>

</listitem>

</varlistentry>

corresponds to the first <command>pg_config</command> command

found in your path.

</para>

<para>

The scripts listed in the <varname>REGRESS</> variable are used for

regression testing of your module, just like <literal>make

installcheck</literal> is used for the main

<productname>PostgreSQL</productname> server. For this to work you need

to have a subdirectory named <literal>sql/</literal> in your extension's

directory, within which you put one file for each group of tests you want

to run. The files should have extension <literal>.sql</literal>, which

should not be included in the <varname>REGRESS</varname> list in the

makefile. For each test there should be a file containing the expected

result in a subdirectory named <literal>expected/</literal>, with extension

<literal>.out</literal>. The tests are run by executing <literal>make

installcheck</literal>, and the resulting output will be compared to the

expected files. The differences will be written to the file

<literal>regression.diffs</literal> in <command>diff -c</command> format.

Note that trying to run a test which is missing the expected file will be

reported as <quote>trouble</quote>, so make sure you have all expected

files.

</para>

<tip>

<para>

The easiest way of creating the expected files is creating empty files,

then carefully inspecting the result files after a test run (to be found

in the <literal>results/</literal> directory), and copying them to

<literal>expected/</literal> if they match what you want from the test.

</para>

</tip>

</sect2>