* Xls Writer - Correct Timestamp Bug, Improve Coverage
I believe that Xls Writer is 100% covered now.
The Xls Writer sets its timestamp incorrectly. The problem is actually
in Shared/Ole::localDateToOLE, which converts its timestamp using
gmmktime; mktime is correct. If I save a file at 3:00 p.m. in San Francisco,
this bug means the time is actually recorded as 3:00 p.m. UTC.
A consequence of this is that if you use Phpspreadsheet to read the
file and save it as a new Xls, the creation timestamp goes further
and further back in time with each generation (or further forward
if east of Greenwich). One of the tests added confirms that
the creation timestamp is consistent with the start and end times
of the test.
The major change in coverage is adding tests to save GIF and BMP
images, which aren't supported in Xls, but are converted to PNG
in the PhpSpreadsheet code.
No code changes. The tests in all of these scripts write to at least
one temporary file, which is then read and not used again. The file
should be deleted to avoid filling up the disk system.
* Handle Error in Formula Processing Better for Xls
When there is an error writing a formula to an Xls file,
which seems to happen when a defined name is part of a formula,
the cell is currently left blank. A better result would be to
write the calculated value of the formula.
* Making Changes Suggested in Review
Per comment from Mark Baker:
1. Made return codes from writeFormula into constants.
2. Skipped redundant call to getCellValue when possible.
3. Added support for bool type, adding additional tests
for bool and string.
Per comment from PowerKiki:
1. Used standardized convention for assigning file name in test.
Since before this change, save would throw Exception, I kept
the unlink for the file in tearDown.
Because even if it doesn't make a difference in practice, it is
technically more correct to call static methods statically. It
also better advertise that those methods can be used from any context.
oleibman