TP2000-1678-Measure-condition-duty-bug

[mattjamc]

TP2000-1678-Measure-condition-duty-bug

Why

Currently, the duty sentence parser returns a float value of the inputted number. If the inputted number cannot be accurately stored as a float, this results in it being replaced with a near approximation with many decimal places. This is causing form validation to fail with an unhelpful error message due to too many decimal places, even if the user only inputted a number with 3 decimal places.

For example, 6.5 GBP / kg or 6.75 would be fine but something like 6.667 would get converted to 6.66699999999999981526 (20 decimal places) and then error.

What

This PR:

• changes the duty sentence parser to return the duty sentence as a Decimal rather than float object
• updates tests to account for it being a decimal now
• adds a check in the form of how many decimal places there are and raises an error - although this was already prevented by it being a DecimalField with max_decimal_places=3, this repeated validation allows a meaningful error message to be surfaced to the user which wasn't before
• adds a new test to confirm the new error message displays on the reference price field