This project is archived and is in readonly mode.
Another rounding problem in number_with_precision
Currently, if you run number_with_precision(9.995, :precision => 2) it returns "9.99". It should return "10.00". You can read a little more information here:
http://stackoverflow.com/questions/4241879/number-to-currency-round...
It basically comes down to this:
# File actionpack/lib/action_view/helpers/number_helper.rb, line 280
rounded_number = BigDecimal.new((number * (10 ** precision)).to_s).round.to_f / 10 ** precision
You can see here that the number is multiplied by 100 before it is converted to BigDecimal. When working with Floats, 9.995 * 100 = 999.4999999999999 which will obviously round down to 999, not up to 1000.
My Fix
I have attached a patch for this that just uses the BigDecimal round function which does this perfectly. In the case where significant is true, it just converts the number to BigDecimal before doing its rounding, etc.
Let me know what you think!
-
number_round_precision_fix.diff
2.68 KB
-
Piotr Sarnacki- Importance changed from to Low
I would apply this patch, but it works only on 1.9, on 1.8 I get one failure:
1) Failure: test_number_with_precision(NumberHelperTest) [./test/template/number_helper_test.rb:105:in `test_number_with_precision' /users/drogus/projekty/rails/activesupport/lib/active_support/testing/setup_and_teardown.rb:67:in `__send__' /users/drogus/projekty/rails/activesupport/lib/active_support/testing/setup_and_teardown.rb:67:in `run' /users/drogus/projekty/rails/activesupport/lib/active_support/callbacks.rb:426:in `_run_setup_callbacks' /users/drogus/projekty/rails/activesupport/lib/active_support/testing/setup_and_teardown.rb:65:in `run']: <"10.0"> expected but was <"9.99">. -
Repository- State changed from new to resolved
(from [006ec77e60163d57d655479602230672d98e0f10]) Fixed number_with_precision rounding error [#6182 state:resolved] https://github.com/rails/rails/commit/006ec77e60163d57d655479602230...
-
Repository
(from [07567aea5f0c6f14a53f511ab4cc46201b669795]) Revert "Fixed number_with_precision rounding error [#6182 state:resolved]"
This reverts commit 006ec77e60163d57d655479602230672d98e0f10.
https://github.com/rails/rails/commit/07567aea5f0c6f14a53f511ab4cc4... -
Piotr Sarnacki
- Milestone cleared.
- State changed from resolved to open
- Assigned user set to Piotr Sarnacki
Awww... sorry guys, I accidently applied that to master and pushed with other fix. I've reverted it now, so it's still open.
Don: please let me know on your findings about that failing test.
-
Don WilsonGood catch Piotr :)
In certain cases in Ruby 1.8, BigDecimal / Float = Float. So, I just had to convert the other side to a BigDecimal before the division.
Just a note, when I convert it to BigDecimal, I have a to_f before the to_s. This was necessary because in Ruby 1.9, many times it is not a Float already, it is a Rational. When you do to_s on a Rational it looks like this "(1/100)". Then, BigDecimal doesn't read it correctly and thinks that you meant 1.0 instead of 0.01.
I have attached a new patch.
-
Repository
- State changed from open to resolved
(from [177749b8bfdbdca7bd996d2370c306b23a88f338]) Fixed number_with_precision rounding error [#6182 state:resolved] https://github.com/rails/rails/commit/177749b8bfdbdca7bd996d2370c30...
-
Repository
(from [f71809f25761440cbec9463bbc082987c90a471b]) Fixed number_with_precision rounding error [#6182 state:resolved] https://github.com/rails/rails/commit/f71809f25761440cbec9463bbc082...
-