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.
* Unzipped Gnumeric File
A Gnumeric file is normally a gzipped Xml file. However, the Gnumeric application will also read an unzipped Xml file. Allow PhpSpreadsheet to do the same.
* Scrutinizer (legitimate)
Fix minor problem.
Reduce number of Phpstan messages by addressing their issues. Reader/Ods will require a separate ticket. Reader/Xls will require many separate tickets.
Adrien Crivelli
oleibman
MarkBaker