* 100% Coverage for Calculation/DateTime
The code in DateTime is now completely covered.
Along the way, some errors were discovered and corrected.
- The tests which have had to be changed at the start of every year are
replaced by more robust equivalents which do not require annual changes.
- Several places in the code where Gnumeric and OpenOffice were thought to differ
from Excel do not appear to have had any justification.
I have left a comment where such code has been removed.
- Use DateTime when possible rather than date, time, or strftime functions to avoid
potential Y2038 problems.
- Some impossible code has been removed, replaced by an explanatory comment.
- NETWORKDAYS had a bug when the start date was Sunday. There had been no tests
of this condition.
- Some functions allow boolean and null arguments where a number is expected.
This is more complicated than the equivalent situations in MathTrig because
the initial date for these calculations can be Day 1 rather than Day 0.
- More testing for dates from 1900-01-01 through the fictitious
everywhere-but-Excel 1900-01-29.
- This showed that there is an additional Excel bug - Excel evaluates
WEEKNUM(emptycell) as 0, which is not a valid result for
WEEKNUM without a second argument.
PhpSpreadsheet now duplicates this bug.
- There is a similar and even worse bug for 1904-01-01 in 1904 calculations.
Weeknum returns 0 for this,
but returns the correct value for arguments of 0 or null.
- DATEVALUE should accept 1900-02-29 (sigh) and relatives.
PhpSpreadsheet now duplicates this bug.
- Testing bootstrap sets default timezone. This appears to be a relic from
the releases of PHP where the unwise decision, subsequenly reversed,
was made to issue messages for
"no default timezone is set" rather than just use a sensible default.
This was a disruptive setting for some of the tests I added.
There is only one test in the entire suite which is default-timezone-dependent.
Setting and resetting of default timezone is moved to that test
(Reader/ODS/ODSTest), and out of bootstrap.
- There had been no testing of NOW() function.
- DATEVALUE test had no tests for 1904 calendar and needs some.
- DATE test changed 1900/1904 calendar in use without restoring it.
- WEEKDAY test had no tests for 1904 calendar and needs some.
- Which revealed a bug in Shared/Date (excelToDateTimeObject was not
recognizing 1904-01-01 as valid when 1904 calendar is in use).
- And an additional bug in that legal 1904-calendar values in the 0.0-1.0
range yielded the same "wrong" answers as 1900-calendar (see "One note" below).
Also the comment for one of the calendar-1904 tests was wrong in attempting
to identify what time of day the fraction represented.
I had wanted to break this up into a set of smaller modules, a process already
started for Engineering and MathTrig.
However the number of source code changes was sufficient that I wanted
a clean delta for this request.
If it is merged, I will work on breaking it up afterwards.
One note - Shared/Date/excelToDateTimeObject, when calendar-1900 is in use,
returns an unexpected result if its argument is between 0 and 1,
which is nominally invalid for that calendar.
It uses a base-1970 calendar in that instance. That check is not justifiable
for calendar-1904, where values in that range are legal,
so I made the check specific to calendar-1900,
and adjusted 3 1904 unit test results accordingly. However, I have to admit that
I don't understand why that check should be made even for calendar-1900.
It certainly doesn't match anything that Excel does.
I would recommend scrapping that code altogether.
If agreed, I would do this as part of the break-up into smaller modules.
Another note -
more controversially, it is clear that PhpSpreadsheet needs to support
the Excel and PHP date formats. Although it requires further study,
I am not convinced that it needs to support Unix timestamp format.
Since that is a potential source of Y2038 problems on 32-bit systems,
I would like to open a PR to deprecate the use of that format.
Please let me know if you are aware of a valid reason to continue to support it.
* Improve Coverage for ODS Reader
Reader/ODS/Properties is now 100% covered.
Reader/ODS is covered except for 1 statement. As the original author
put it, "table-header-rows TODO: figure this out ... I'm not sure that
PhpExcel has an API for this". I'm still thinking about it, but, so far,
I agree with the author.
There are minimal code changes.
- Several places test !zip->open() to see whether the test failed.
However, zip->open() returns true or a string, so the test never
detects failure. Change to zip->open() !== true. No previous tests.
- Suppress warning messages from simplexml_load_string (there had
been no tests for invalid xml).
- One document property was misnamed, and one non-existent property
was tested for.
I added a number of tests, creating an ODS directory, and moving
OdsTest to that directory.
* Scrutinizer Recommendation
Unused variable in one test.
* Update CHANGELOG
Co-authored-by: Adrien Crivelli <adrien.crivelli@gmail.com>