David Scotson

Clean is the base theme that Essential inherits from, so they share a lot, but Clean is more bare-bones, like the Base theme that many other themes inherit from.

Regarding your questions, the first "supportscssoptimisation" is related to an extra step of CSS minification. Moodle sometimes has CSS for the same things in two places, e.g. the size of an element might be set in the Base theme, then the color of the element set in the Standard theme and then all that CSS will be combined into one file. Moodle has a process that will search through your CSS and combine:

.example { width: 60%; }
... lots of other CSS ...
.example { color: red;}

into

.example { width: 60%; color: red;}

But this process had some issues with more advanced CSS (I think media queries confused it? Or pre-minified CSS?) so themes can opt-out of this step if it causes problems.

The second, "yuicssmodules" lets you opt out of including the YUI CSS if your theme doesn't need it. There's not much to the YUI CSS, most will be duplicated by any standard CSS framework you import. It also lets you avoid some bugs created by this CSS (e.g. MDL-27774, which is fixed in Clean and it's child themes, but not in Base/Standard etc.)

You can find these documented in the theme_config class here:

https://github.com/moodle/moodle/blob/master/lib/outputlib.php#L115

There used to be online docs for this (just the same info but presented better), but they seem out of date now and don't have the newer additions:

http://phpdocs.moodle.org/HEAD/core/lib/theme_config.html

Your website already has a passing resemblance to the Essential theme, so I'd have a look at that (it also does well on you three bullet points).

http://docs.moodle.org/25/en/Essential_theme

I think the author stated that he was planning to support 2.6 from now on, but if you're planning to put some effort towards this anyway then supporting Essential in 2.5 (at least until you upgrade) is probably do-able.

After reading the various links provided this seems like the correct answer.

Can I suggest that the text on the common test failures page be changed to something more like:

"You probably are running MySQL. These tests should pass if you use utf8_bin collation on your database for unit tests, but we recommend utf8_unicode_ci for actual Moodle sites. Work is being done to resolve this issue, read more about the Database collation issue."

It's possibly also a good idea to put some of this info (or a link to that page) in the actual test output.

This page outlines some common unit test failures:

http://docs.moodle.org/dev/Common_unit_test_problems

Two of them involve MySQL and the solution each time is:

"Your Database is incorrectly configured. You probably are running MySQL and need to switch to utf8_bin collation."

But on the wiki page about MySQL:

http://docs.moodle.org/26/en/MySQL

it says: "We recommend you use utf8_unicode_ci for collation."

So which is correct, utf8_bin_collation or utf8_unicode_ci?

That's very cool. I was just about to look into running behat on travis as we plan our update to 2.6

I'm also looking into code-coverage, mutation testing and running various static analysis tools though at the moment the main problem with all of them is how long they take to run.