@c -*- coding: utf-8; mode: texinfo; -*-
@node Regression tests
@chapter Regression tests

@menu
* Introduction to regression tests::
* Current regtest output::
* Comparison regtest output::
* MusicXML tests::
@end menu


@node Introduction to regression tests
@section Introduction to regression tests

LilyPond has a complete suite of regression tests that are used
to ensure that changes to the code do not break existing behavior.
These regression tests comprise small LilyPond snippets that test
the functionality of each part of LilyPond.

Regression tests are added when new functionality is added to
LilyPond.  They are also added when bugs are identified.  The
snippet that causes the bug becomes a regression test to verify
that the bug has been fixed.

The regression tests are automatically compiled using special @code{make}
targets.  The output of the regression tests is also automatically
checked to identify changes in LilyPond output.

The output of the regression tests is available on the website
for every stable version of LilyPond.  This allows the comparison
of different versions to see when bugs appeared.


@node Current regtest output
@section Current regtest output


@node Comparison regtest output
@section Comparison regtest output


@node MusicXML tests
@section MusicXML tests