Fix#4213. Early versions of Php 8.4 caused problems for some Excel functions, among them ROUNDDOWN and ROUNDUP. New code was added which seemed to work for 8.4 and all prior releases (back to 7.4). However, as the issue shows, there is a problem with the new logic that had not been a problem for prior releases (PhpSpreadsheet 1.29.1 with Php 8.3 or earlier).
As it happens, some time after 8.4 broke the existing functionality, new features were added to it which enabled much cleaner logic. The code will now take this cleaner path when available, and revert to the older logic when not. This appears to work for all relevant Php releases, at least till the next non-match between PhpSpreadsheet and Excel is reported.
And, having made the change to ROUNDDOWN, it occurred to me that ROUNDDOWN always returns the same result as TRUNC (they differ only in number of required arguments). So I changed TRUNC to call ROUNDDOWN, and that didn't break anything. So I will keep that change. This probably means I should change Calculation so that ROUNDDOWN is called automatically, and deprecate TRUNC. That can happen at a later time.
Fix#4113. TRUNC isn't always producing the expected result. There was a promising algorithm at https://stackoverflow.com/questions/4668628/truncate-float-numbers-with-php from user Juan. It works through Php8.3, but failed in Php8.4 (more on this later). User Savageman on the same page has a solution that needs work, but, once the work had taken place, it works on Php8.1-8.4.
The ROUNDUP and ROUNDDOWN functions were adversely affected by Php8.4, probably for the same reasons as Juan's TRUNC suggestion. I put a kludge in place for them some time ago, but I wasn't happy with it. The solution used for TRUNC here suggested a change to the ROUNDUP and ROUNDDOWN code that would no longer require the kludge. The change to those functions now works more cleanly on Php8.1-8.4.
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.
* ROUND Accepts null, false, and true as First Parameter
Issue #1789 was addressed by PR #1799. In a follow-up discussion,
it came to light that ROUND was not handling the unexpected case where the
first parameter is an empty cell in the same manner that Excel does.
Subsequent investigation showed that a boolean first parameter is permitted.
I broadened my investigation to include the following related functions.
- ROUNDUP
- ROUNDDOWN
- MROUND
- TRUNC
- INT
- FLOOR
- FLOOR.MATH
- FLOOR.PRECISE
- CEILING
- CEILING.MATH
- CEILING.PRECISE
All of these allow a NULL first parameter, and all except MROUND allow boolean.
For completeness, I will note that all treat null string as invalid.
I suspect there are other functions which permit
similarly unexpected parameters, but I consider them out of scope for this PR.
CEILING.MATH and CEILING.PRECISE were unimplemented, and are now supported
as part of this PR.
The tests for each of these functions have been re-coded, though all the original
test data is still included in the test cases, plus several new cases for each.
The new tests now take place as a user would invoke the functions,
through a spreadsheet cell rather than a
direct call to the appropriate function within Calculation/MathTrig.
Aside from being more realistic, the new tests are also more complete.
For example, FLOOR.MATH can take from 1-3 arguments, and the existing tests
confirmed that the function in Calculation could handle a single argument.
However, the function list in Calculation.php erroneously set the number of
arguments for FLOOR.MATH to exactly 3, so, if a user tried to get the calculated
result of a cell containing FLOOR.MATH(1.2), the result would be an Exception.
Aside from the parameter support, there are a few minor code changes.
Ods, as well as Gnumeric, allows the omission of the second parameter for
FLOAT and CEILING; Excel does not. A potential divide-by-zero error is
avoided in CEILING, FLOOR, and FLOORMATH.
I will note that it would probably be beneficial in terms of maintainability
to break MathTrig up into many individual modules. The same would hold for the
other Calculation modules. I would be willing to look into this if you agree
that it would be worthwhile.