Trailing space issue in Angular Locale

[TudorSfatosu]

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Do you want to request a feature or report a bug?
Reporting a bug

What is the current behavior?
A trailing space is added to RO and IT angular locale, maybe in similar locales as well.

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://plnkr.co or similar (template: http://plnkr.co/edit/tpl:yBpEi4).
DEMO: http://jsfiddle.net/4gyjtu8g/245/

What is the expected behavior?
There should be no trailing space, like the EN angular locale

What is the motivation / use case for changing the behavior?
To fix a general bug

Which versions of Angular, and which browser / OS are affected by this issue? Did this work in previous versions of Angular? Please also test with the latest stable and snapshot (https://code.angularjs.org/snapshot/) versions.
http://ajax.googleapis.com/ajax/libs/angularjs/1.3.0/angular.min.js
https://cdnjs.cloudflare.com/ajax/libs/angular-i18n/1.5.8/angular-locale_ro.js

Other information (e.g. stacktraces, related issues, suggestions how to fix)

[gkalpak]

This is kind of expected and is not specific to the ro locale. All locales that included a space before or after the currency symbol are affected in the same way.

According to the ro locale file, the currency-formatted number should be suffix with <CURRENCY_SYMBOL> (a space, followed by the currency symbol).
By default, the currency symbol is RON: currencyFilter(10) --> '10.00 RON'
When you are replace the default currency symbol with the empty string, the result will still contain the space: currencyFilter(10, '') --> '10.00 '

You won't see the same problem with the default en locale, because in that locale there is no space between the number and the currency symbol:
currencyFilter(10) --> '$10' (no space before 10)
currencyFilter(10, '') --> '10' (no space before 10)

The easy way out is to trim the output before returning it to the user, but I am not sure if there are valid usecases for having leading/trailing whitespace characters.

Does anyone happen to have any insights on that?

Obviously, it is very easy to work-around it yourself - if you are sure you don't need the extra space - by:

1. Trimming the output:

   {{ (10 | currency:'').trim() }}

   (Bonus points for creating a trim filter 😛)

2. Create your custom filter that wraps currency and automatically trims the output:

   .filter('currencyNoSymbol', function currencyNoSymbolFactory(currencyFilter) {
     return function currencyNoSymbol(input, fracSize) {
       var output = currencyFilter(input, '', fracSize);
       return output && output.trim();
     };
   })

   Then use it like this:

   {{ 10 | currencyNoSymbol }}

3. Overwrite/Decorate the built-in currency filter to always trim the output (then use it normally).

EDIT: These are suggested as work-arounds for people to use in their apps, until this is properly fixed in core.

[wesleycho]

I think it make sense to have the currency filter do the trimming in core itself, as it sounds like it is unintended behavior in this case. The overhead added should be minimal, and it would be easy to address without impacting anyone.

[gkalpak]

The only thing I am concerned/unsure about, is whether there is some locale that requires a space before/after its values. (I doubt it, but I am not sure either.)

[gkalpak]

From a quick search through the i18n files I didn't find any locale for which the trimming would be problematic.

This is more involved though, because there is another usecase that suffers from the same issue, but won't be solved by trimming: negative values for locales that have the currency symbol before the number. E.g.:

// Assuming a locale that formats `10` as `X 10.00` and `-10` as `-X 10`
// (where `X` is the currency symbol):

// Desired
currencyFilter(-10, '')   // --> '-10'

// Actual
currencyFilter(-10, '')   // --> '- 10' (space between `-` and `10`)

[TudorSfatosu]

I want to thank you guys for the involvement on this matter.
I don't feel like adding more for the moment.
If you feel you have more questions for me, just let me know!