Add support for one digit decimals (FORMAT_NUMBER_0, FORMAT_PERCENTAGE_0)

[nohn]

This is:

- [ ] a bugfix
- [x] a new feature

Checklist:

• Changes are covered by unit tests
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change
• Documentation is updated as necessary

Why this change is needed?

Because numbers are often rounded to one digit.

[oleibman]

Might you be able to add unit tests which demonstrate that your new constants work as expected?

[nohn]

Might you be able to add unit tests which demonstrate that your new constants work as expected?

To be honest: I don't fully understand, how NumberFormats are tested currently and what the existings tests actually test.

But my guess is that with

tests/PhpSpreadsheetTests/Style/NumberFormatTest.php
tests/data/Style/NumberFormat.php and
src/PhpSpreadsheet/Style/NumberFormat/Formatter.php

that already happens automagically (but I don't fully understand, what PhpOffice\PhpSpreadsheet\Style\NumberFormat\Formatter::toFormattedString() does),

[oleibman]

Agreed that the current NumberFormat tests don't provide a particularly good template for you to decide how to add tests for your change. Here's what I'd like to see you add to tests/data/Style/NumberFormat.php:

use PhpOffice\PhpSpreadsheet\Style\NumberFormat

// result, value, format (note change in order in this comment)

...

    [
        'yourExpectedResult',
        'yourInputValue',
        NumberFormat::FORMAT_NUMBER_0,
    ],

Obviously, substitute suitable values for yourExpectedResult and yourInputValue. I would expect to see at least one test for a number with no decimal portion, with one decimal digit, and with more than one decimal digit; possibly make one of the tests format zero or a negative number. I would expect a similar set of tests for FORMAT_PERCENTAGE_0.

[nohn]

Tests added. I've skipped an obvious one, as this one

    [
        '1.2%',
        '0.0115',
        NumberFormat::FORMAT_PERCENTAGE_0,
    ],

fails:

1) PhpOffice\PhpSpreadsheetTests\Style\NumberFormatTest::testFormatValueWithMask with data set #121 ('1.2%', '0.0115', '0.0%')
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1.2%'
+'1.1%'

/home/sebastian/Projects/oss/PHPOffice/PhpSpreadsheet/tests/PhpSpreadsheetTests/Style/NumberFormatTest.php:50

2) PhpOffice\PhpSpreadsheetTests\Writer\Html\HtmlNumberFormatTest::testFormatValueWithMask with data set #121 ('1.2%', '0.0115', '0.0%')
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1.2%'
+'1.1%'

/home/sebastian/Projects/oss/PHPOffice/PhpSpreadsheet/tests/PhpSpreadsheetTests/Writer/Html/HtmlNumberFormatTest.php:180

However, also this one fails with the same error, so I would say it's not on my code:

    [
        '1.12%',
        '0.01115',
        NumberFormat::FORMAT_PERCENTAGE_00,
    ],

The failed test suggests that the formatting per se is OK, as it is a masking, not a rounding, but why does

    [
        '1.2%',
        '0.0116',
        NumberFormat::FORMAT_PERCENTAGE_0,
    ],

Pass the test then and is rounded? To me it looks like .5 is rounded down instead of up if masking is used.

[oleibman]

l would like to research your test failures. They seem similar to problems which appeared to be fixed by PR #2399. I agree that your change is an innocent bystander here, but let's see if we can figure out what's going wrong and fix it.

[nohn]

OK.

Tests are in https://github.com/nohn/PhpSpreadsheet/tree/strange_rounding_format_value_with_mask.

Run with those tests failing: https://github.com/nohn/PhpSpreadsheet/actions/runs/1795815772

[oleibman]

The earlier PR fixed Style/NumberFormat/NumberFormatter.php. It did not address PercentageFormatter.php, which is why you are seeing these new problems (and why adding the tests turns out to have been a better idea than expected). Can you try making the same sort of change to PercentageFormatter to see if it helps? At the end, instead of:

        return sprintf($mask, $value);

Substitute the following:

        /** @var float */
        $valueFloat = $value;

        return sprintf($mask, round($valueFloat, $decimalPartSize));

[nohn]

Thanks! That seems to fix it. To keep this PR focused on the new number formats, I've create a separate one for the bugfix: #2555

[oleibman]

Made it to the finish line at last. Thank you for your contribution.

[nohn]

You're welcome.