Successor to PR #3523. There are 494 single-line changes (`public function provider` to `public static function provider`) in this PR. None of these were made manually; they were all created with the following script (adapted from
https://stackoverflow.com/questions/25909820/how-to-recursively-iterate-through-files-in-php):
```php
$dir = 'C:/git/unit10prep2/tests/PhpSpreadsheetTests';
$it = new RecursiveDirectoryIterator($dir);
// Loop through files
foreach(new RecursiveIteratorIterator($it) as $file) {
if ($file->getExtension() === 'php') {
$contents = file_get_contents($file);
$new = preg_replace('/public function (\\w*)([Pp])rovider/', 'public static function $1$2rovider', $contents);
if ($new !== $contents) {
echo "changing $file\n";
file_put_contents($file, $new);
}
}
}
```
After this PR, there will be one more, with a small number of test changes, and enabling PhpUnit 10 for Php 8.1+.
* Big Memory Leak in One Test
Many tests leak a little by not issuing disconnectWorksheets at the end. CellMatcherTest leaks a lot by opening a spreadsheet many times. Phpunit reported a high watermark of 390MB; fixing CellMatcherTest brings that figure down to 242MB. I have also changed it to use a formal assertion in many cases where markTestSkipped was (IMO inappropriately) used.
* Another Leak
Issue2301Test lacks a disconnect. Adding one reduces HWM from 242MB to 224.
* Allow single-cell checks on conditional styles, even when the style is configured for a range of cells
* Work on the CellMatcher logic to evaluate Conditionals for a cell based on its value, and identify which conditional styles should be applied
* Refactor style merging and cell matching for conditional formatting into separate classes; this should make it easier to test, and easier to extend for other CF expressions subsequently
* Added support for containsErrors and notContainsErrors
* Initial work on a wizard to help simplify created Conditional Formatting rules, to ensure that the correct expressions are set
* Further work on extending the Conditional Formatting rules to cover more of the options that are available in MS Excel
* Prevent phpcs-fixer from removing class @method annotations, used to identify the signature for magic methods used in Wizard classes
* Implement `fromConditional()`` method to allow the creation of a CF Wizard from an existing Conditional
* Ensure that xlsx Reader picks up the timePeriod attribute for DatesOccurring CF Rules
* Allow Duplicates/Uniques CF Rules to be recognised in the Xlsx Reader
* Basic Xlsx reading of CF Rules/Styles from <extLst><ext><ConditinalFormattings> element, and not just the <ConditinalFormatting> element of the worksheet
* Add some validation for operands passed to the CF Wizards
- remove any leading ``=` from formulae, because they'll be embedded into other formulae
- unwrap any string literals from quotes, because that's also handled internally
Handle cross-worksheet cell references in cellReferences and Formulae/Expressions
* re-baseline phpstan
* Update Change Log with details of the CF Improvements