= Writing Reftests = == Reftests in WebKit == Reftest uses a HTML file ('-expected.html') to represent an expected rendering result, instead of pre-generated expected files (such as '-expected.txt', '-expected.checksum' and '-expected.png'). Let's see the following sample reftest. * hello.html {{{ reftest0001 Hello! }}} * hello-expected.html {{{ reftest0001 Hello! }}} A run-webkit-tests recognizes this is a reftest and runs the test as if this is a normal layout test. You can think that a '-expected.html' file is used to produce a '-expected.checksum' and a '-expected.png' on the fly. If there is a difference between the rendering results of two html files, the test fails. There is yet another type of reftests, 'a mismatch reftest'. Let's see the following sample 'mismatch' reftest. * foo.html {{{ reftest0001 Hello! }}} * foo-expected-mismatch.html {{{ reftest0001 Hello! }}} In this case, the test fails if both HTML files produce the same results. The test passes if there is any differences between them. You can see the sample reftest here: http://trac.webkit.org/changeset/81644 == File naming convention == * (normal) reftests: {testname}.html and {testname}-expected.html * 'mismatch' reftests: {testname}.html and {testname}-expected-mismatch.html == FAQ == * Q. Can we use a platform-specific expected html file? * A. Yes. Reftests try to obey the current layout test mechanism as possible as we can. * Q. What happens if we 'rebase' for reftests? * A. A 'Rebasing' doesn't make sense in reftests. A rebase line tool simply skips reftests. * Q. If we have hello.html, hello-expected.html and hello-expected-mismatch.html files, what happens? Does that run two reftests? * A. No. That should be considerd a wrong configuration. Don't use one test html file for both a (normal) reftest and a 'mismatch' reftest. Please choose the different file name for each test. * Q. Can we use '-expected.html' and '-expected.{checksum,png}' at the same time for one test file? * A. No. * Q. What kind of failures reftests produce? * A. If an image comparison failure happens in reftests, that is marked as a 'ImageOnlyFailure'. If either of two html files crashes, it is considered as 'Crash'. So does 'Timeout'. == References == * https://developer.mozilla.org/en/Creating_reftest-based_unit_tests * http://mxr.mozilla.org/mozilla-central/source/layout/tools/reftest/README.txt