In all cases changes have been kept to a minimum while not making
the code completely horrible. For example, there are many instances
where it would probably be better to rewrite a query entirely, but
I have not done that (in order to reduce the risk of changes).

The function must be static and actually has to do what it is supposed to. It also breaks PHP 8.0

Co-authored-by: Paul Holden <paulh@moodle.com>

The optional parameters of assertEquals() and assertNotEquals()
are deprecated in PHPUnit 8 (to be removed in PHPUnit 9):

- delta => use assertEqualsWithDelta()
- canonicalize => use assertEqualsCanonicalizing()
- ignoreCase => use assertEqualsIgnoringCase
- maxDepth => removed without replacement.

More info @ https://github.com/sebastianbergmann/phpunit/issues/3341

Initial search done with:

ag 'assert(Not)?Equals\(.*,.*,' --php

Then, running tests and fixing remaining cases.

Both assertContains() and assertNotContains() are deprecated in PHPUnit 8
for operations on strings. Also the optional case parameter is. All uses
must be changed to one of:

- assertStringContainsString()
- assertStringContainsStringIgnoringCase()
- assertStringNotContainsString()
- assertStringNotContainsStringIgnoringCase()

More info: https://github.com/sebastianbergmann/phpunit/issues/3422

Regexp to find all uses:

ag 'assert(Not)?Contains\('

While this is not strictly required, because removal will
happen in PHPUnit 9.0, we are already getting rid of all
uses in core.

From release notes:https://phpunit.de/announcements/phpunit-8.html

The annotations `@expectedException`, `@expectedExceptionCode`,
`@expectedExceptionMessage`, and `@expectedExceptionMessageRegExp`
are now deprecated.
Using these annotations will trigger a deprecation warning
in PHPUnit 8 and in PHPUnit 9 these annotations will be removed.

Also, all uses of expectExceptionMessageRegExp() has been moved
to expectExceptionMessageMatches(). See https://github.com/sebastianbergmann/phpunit/issues/3957

TODO: Various weirdness found while doing the changes with these tests:
- vendor/bin/phpunit lib/tests/exporter_test.php (created MDL-69700)
- vendor/bin/phpunit competency/tests/external_test.php (same issue than prev one)
- vendor/bin/phpunit question/engine/tests/questionengine_test.php (created MDL-69624)
- vendor/bin/phpunit lib/tests/event_test.php (created MDL-69688)

While this is not strictly required, because removal will
happen in PHPUnit 9.0, we are already getting rid of all
uses in core.

From release notes:https://phpunit.de/announcements/phpunit-8.html

assertInternalType() is deprecated and will be removed in
PHPUnit 9. Refactor your test to use assertIsArray(), assertIsBool(),
assertIsFloat(), assertIsInt(), assertIsNumeric(), assertIsObject(),
assertIsResource(), assertIsString(), assertIsScalar(),
assertIsCallable(), or assertIsIterable() instead.

Component names should always support numbers (but the first character).
This patch will add PARAM_COMPONENT the expected regular expression
to validate the expected format.

Returns a formatted string representation of the difference between two
timestamps, defaulting to 'Xd Xh Xm' format, but supporting custom
format strings containing any chars from:
https://www.php.net/manual/en/dateinterval.format.php.

Commit 637da99e has introduced changes
for removing trailing zeroes from the output of function format_float.
Due to a small omission, the function causes a PHP warning when the
string decsep is set to a tilde character ('~'). This is rarely the
case.

The bug lies in using PHP function preg_replace with a string that
contains external input (in this case, including decsep), but without
escaping it for PCRE processing.

This commit fixes the function to also support a tilde character in
string decsep. It also adds tests for having tilde as decimal separator.

Thanks-To:  Jake Dallimore <jake@moodle.com>

This chagne adds support for a new feature known as Context Locking.
This allows a context to be locked, thereby removing all write
capabilities for all users (including admin) for that context, and all
child contexts.

Improve the format of the HTML representing a forum post.

1. Use <article> tag to mark it correctly.
2. Use <time> tag to include the real datetime information.
3. Use <address> tag to specify who and when the post came from.
4. Use heading level tags to mark the subject of each post.
5. Properly nest reply posts within their parent <article>
6. Use a header tab for each article to split the metadata from the content.
7. Use CSS to separate links, not text content.

Because posts are now nested properly, the heading for each one refers to it's own article
and we don't need to generate arbitrary heading level tags depending on how deep the post
is nested.

Places that display list of users (such as course participants page)
with additional identifier fields now respect the user's permission to
view other users' hidden profile fields.

A new method shorten_filenames has been added to moodlelib.