* Let Phpstan Run on Samples
Phpstan currently analyzes all source and test members. We already run phpcs and php-cs-fixer on samples as well. I would expect that samples are often used as templates for code in userland; it behooves us to be at least as careful with those members as for the others which are already being analyzed. Aside from 1300+ messages `Variable $helper might not be defined.`, which will be suppressed in phpstan.neon.dist, there are really only a few changes needed for sample members, so that part of the code base was already in good shape, and is now even better. No annotations were needed.
* Scrutinizer 2 out of 3
1 false positive, now suppressed; fix other 2.
* Remove Dead Code
* Very Minor Changes
* Add infra
19_NamedRange.php was not changed to use absolute addressing when that was introduced to Named Ranges. Consequently, the output from this sample has been wrong ever since, for both Xls and Xlsx.
There was an additional problem with Xls. It appears that the Xls Writer Parser does not parse multiple concatenations using the ampersand operator correctly. So, `=B1+" "+B2` was parsed as `=B1+" "`. I believe that this is due to ampersand being treated as a condition rather than an operator; `A1>A2>A3` isn't valid, but `A1&A2&A3` is. My original PR (#1992, which I will now close) only partially resolved this, but I think moving ampersand handling from `condition` to `expression` is fully successful.
There are already more than ample tests for Named Ranges, so I did not add a new one for that purpose. However, I did add a new test for the Xls parser problem.
oleibman
Owen Leibman
Adrien Crivelli