node-stringprep


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Exposes predefined Unicode normalization functions that are required by many protocols. This is just a binding to ICU, which is said to be fast..

If ICU is not available then we make use of JavaScript fallbacks.

Usage

``javascript
var StringPrep = require('node-stringprep').StringPrep;
var prep = new StringPrep('nameprep');
prep.prepare('Äffchen') // => 'äffchen'
`

For a list of supported profiles, see node-stringprep.cc

Javascript fallbacks can be disabled/enabled using the following methods on the StringPrep object:

`javascript
var prep = new StringPrep('resourceprep')
prep.disableJsFallbacks()
prep.enableJsFallbacks()
`

Javascript fallbacks are enabled by default. You can also check to see if native icu bindings can/will be used by calling the isNative() method:

`javascript
var prep = new StringPrep('resourceprep')
prep.isNative() // true or false
`

We also implement the ToASCII and ToUnicode operations as defined in the IDNA RFC 3490. These routines convert Unicode to ASCII with NamePrep and then with Punycode, and vice versa.

`javascript
var nodeStringPrep = require('node-stringprep');
nodeStringPrep.toASCII('i♥u') // 'xn--iu-t0x'
nodeStringPrep.toUnicode('xn--iu-t0x') // 'i♥u'
`

The operations can be finessed with an optional second argument, a set of boolean flags:

`javascript
nodeStringPrep.toASCII('i♥u', {
allowUnassigned: true, // allow unassigned code points to be converted
throwIfError: true, // throw exception if error, don't return string unchanged
useSTD3Rules: true // use the STD3 ASCII rules for host names
})
nodeStringPrep.toUnicode('xn--iu-t0x', {
allowUnassigned: true // allow unassigned code points to be converted
})
`

Installation

`
npm i node-stringprep
`

If libicu isn't available installation will gracefully fail and javascript fallbacks will be used.

If experiencing issues with __node-gyp__ please see https://github.com/TooTallNate/node-gyp/issues/363 which may be able to help.

$3

`
apt-get install libicu-dev
`

$3

`
yum install libicu-devel
`

$3

`
emerge icu
`

$3

`
port install icu +devel
`

#### Boxen

`
sudo ln -s /opt/boxen/homebrew/Cellar/icu4c/52.1/bin/icu-config /usr/local/bin/icu-config
sudo ln -s /opt/boxen/homebrew/Cellar/icu4c/52.1/include/* /usr/local/include
`

#### Homebrew
brew install icu4c
ln -s /usr/local/Cellar/icu4c//bin/icu-config /usr/local/bin/icu-config
ln -s /usr/local/Cellar/icu4c//include/* /usr/local/include

If experiencing issues with 'homebrew' installing version 50.1 of icu4c, try the following:

`
brew search icu4c
brew tap homebrew/versions
brew versions icu4c
cd $(brew --prefix) && git pull --rebase
git checkout c25fd2f $(brew --prefix)/Library/Formula/icu4c.rb
brew install icu4c
`

Running Tests

`
npm test
``