While we might never be able to have 100% of our code strict, we can at
the very least do it for all of our tests. This ensures that our tests
are using our API with the types as intended by the test author, and not
silently be cast to what our API requires.
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, $new);
}
}
}
```
After this PR, there will be one more, with a small number of test changes, and enabling PhpUnit 10 for Php 8.1+.
* Permit Date/Time Entered on Spreadsheet to be Calculated as Float
Fix#1416. I do not entirely understand the use case for this old issue, but resolving it seems straightforward. Issue complains that user-entered date/time fields may be interpreted as either float or int when PhpSpreadsheet reads them. Issue suggests getCalculatedValue treat all date/time fields as float; that seems like a breaking change. However, adding an option to permit it seems okay. That option might be implemented as either a property of Calculation, or a static property of Cell. Since the changed logic is found in Cell (and Shared/Date), I opted for the latter.
In Cell, the property `$parent` is incorrectly described in doc block as `Cells`, and should be `?Cells`. This change eliminates some Phpstan and Scrutinizer problems, and should allow the elimination of some try/catch blocks - I have not done an exhaustive search for those.
Calls to `isDateTime` could have affected activeSheet and selectedCells; they no longer can. Optional parameters are added to it and the functions it calls to accommodate the new functionality; the defaults for the new parameters will, of course, return the same result as the earlier versions of the functions would have returned.
* Scrutinizer - Self-inflicted
Tests used constant which I deprecated.