Inconsistent rounding on some units

[filipefurtad0]

Description

Closely related to https://github.com/openfoodfoundation/wishlist/issues/6

There's some issues with rounding issues with units like L, inserting a value respective to a given unit appears in the "Display as" field as a decimal, with plenty of significant digits. (see pic/video below). This can easily appear in the shopfront.

A known combination is Volume (L), with value 0.7; others have been observed.

Expected Behavior

Inserting 0.7 should appear as 700 mL.

Actual Behaviour

Inserting 0.7 L appears as 699.99999999.... mL

Steps to Reproduce

1. Create or edit a Volume (L) product.
2. Type 0.7 on the "Value" field.
3. See the "Display as" field.

Animated Gif/Screenshot

This value gets actually gets stored and is even displayed in the shopfront:

Update
This issue also appears on the inventory (https://github.com/openfoodfoundation/wishlist/issues/6) and Order Cycles page:

Workaround

You can edit the display as field and type any value, overriding the placeholder value.

Severity

bug-s3: a feature is broken but there is a workaround

Your Environment

• Version used: first spotted here, maybe v3.6.3?
• Browser name and version: Firefox 88
• Operating System and version (desktop or mobile): Desktop Ubuntu 20.04

Possible Fix

[jibees]

Ahah, ❤️ javascript:

[lauriewayne]

Possibly related but maybe not: when using imperial measures (lbs or oz) we are seeing a similar display problem show up when the "Display as" field is empty (i.e. default/auto generated) and the weight is 12 or 24 (does not happen when the weight is 8, 16, 15, 30, and so on, and does not happen for metric measures or items).

In back end:

In shop:

When the "Display as" field is manually updated to "12 ounces" in the variant edit, the display looks better:

But the back end still shows 11.999999999999998 even after manually changing it to 12:

[lauriewayne]

Looks like an imperial measures only issue. Moving this comment to openfoodfoundation/wishlist#219.

[drummer83]

Oh no, this one is back! 😢

'Display as' and 'edit variant' are ok, but the variants list and the shopfront are not:

Reopening!

[filipefurtad0]

Closing from merging PR #12950.