Why does Angular need its own angular.uppercase and lowercase methods?

[thorn0]

What's wrong with the standard toUpperCase and toLowerCase methods?
Looks like there was some issue with the Turkish locale, but does it still exist in the browsers supported by Angular? I asked about it on StackOverflow, but didn't get an answer.

[realityking]

The reason is documented in a source comment:

angular.js/src/Angular.js

Lines 161 to 163 in e5d1d65

	// String#toLowerCase and String#toUpperCase don't produce correct results in browsers with Turkish
	// locale, for this reason we need to detect this case and redefine lowercase/uppercase methods
	// with correct but slower alternatives.

It's also documented on MDN: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toLocaleLowerCase

Lastly, I think the StackOverflow answers were pretty accurate.

[thorn0]

Neither the comment nor the SO answers are informative.
The question is

In which exactly JS engines are toLowerCase() & toUpperCase() locale-sensitive?"

How do those answers answer it? How does the source comment answer it? Moreover, the comment and the answers contradict each other. In theory, toLowerCase() & toUpperCase() shouldn't be locale-sensitive. That's what one of the answers says. And your MDN link says the same thing. But the comment states something very opposite:

String#toLowerCase and String#toUpperCase don't produce correct results in browsers with Turkish locale

Again, in which exactly browsers does this happen?

[wesleycho]

Searching on Google, this seems like a general problem due to the Turkish language itself - this article seems to explain it: http://www.i18nguy.com/unicode/turkish-i18n.html

If I had to guess, this is a problem with every browser.

[thorn0]

The general problem exists, that's true. But who said that it (still) exists also in JavaScript? Who faced it during say last 10 years?

[wesleycho]

I doubt it was pulled from thin air - that is not how the Angular team functions.

[thorn0]

The hacks and workarounds for IE8 are being removed from the code of Angular now. But this thing looks like a workaround for a bug in some even older browser.

[pkozlowski-opensource]

@thorn0 why not testing on your end (you seem to be from Turkey) and sending a PR to remove those work-arounds if no longer necessary? I'm pretty sure that everyone would be more than happy to remove unnecessary code.

[thorn0]

I wanted to know why this code is there. If the issue still exists (if ever existed) in some browser, it'd be nice to know about it. I'm going to check it in different browsers, but of course I don't have access to all the needed OS+device+browser combinations.

[pkozlowski-opensource]

@thorn0 AFAIK Turkish locale was the only / main reason. So if you can confirm that this bug doesn't affect users of modern browsers and submit a PR to see if all the tests are passing on CI this could potentially be merging. But as you are saying, no one will be able to re-test this on all the possible devices in the wild, so we might potentially introduce a breaking change here....

[thorn0]

BTW, another library containing code like that is Google Closure Library. See these lines. Supposedly, it came to Angular from there.