LibSkycoin for Javascript

Javascript client library for Skycoin API. This library is a Javascript assembly generated with SWIG to access Skycoin API from Javascript.

Table of Contents

• LibJS-skycoin wrappers for the Skycoin cipher
  • Installation
  • Using the API
    • Naming
    • Parameters
      • Handles
      • Byte Slices
      • Structures
      • Fixed Sized Arrays
      • Other Slices
    • Memory Managemanet
• Make rules
• Development setup
• LibJS Skycoin wrappers for the Skycoin client API
  • Clients
  • LibSky-Axios Client
  • LibSky-Node Client

LibJS Skycoin wrappers for the Skycoin cipher

LibJS Skycoin is an assembly that provides wrappers to the Skycoin core cipher API's, implemented in golang, hence linking directly to the original node code. No transpilation involved.

Installation

Before installing, make sure you understand the choices available to install a NPM package . For instance, in case of installing NPM client tools the process would look like this, using npm install command.

npm install libskycoin

Install from sources

Download the repository from http://github.com/simelo/libjs-skycoin.git. Execute (make build) to install the library.

Usage

Naming

The exported function in Libskycoin JS have the following naming format: SKY_package_func_name where package is replace by the package where the original Skycoin function is and func_name is the name of the function. For example, LoadConfig function from cli package is called in .Net SKY_cli_LoadConfig

Parameters

All skycoin exported functions return an error object as the last of the return parameters. In .NET error is return as an uint and it is the first return parameter. The rest of the parameters are returned in the same order.

Receivers in Skycoin are the first of the input parameters. Simple types, like integer, float, string will be used as the corresponding types in JS, except what act as pointers.

Handles

Some of Skycoin types are too complex to be exported to a scripting language. So, handles are used instead. Therefore all functions taking a complex type will receive a handle instead of the original Skycoin type. For example, having these functions exported from Skycoin:

  func LoadConfig() (Config, error)
  func (c Config) FullWalletPath() string

Config is a struct type that is treated as a handle in Libskycoin JS . The usage in .Net will be:

      var skycoin = require('./lib/skycoin/build/Release/skycoin');
      var configHandle = skycoin.new_Config_HandlePtr();
      var err = skycoin.SKY_cli_LoadConfig(configHandle);
      if(err == skycoin.SKY_OK) {
        // SkY_OK means no error
        var fullWalletPath = new _GoString()_;
        err = skycoin.SKY_cli_FullWalletPath(configHandle,fullWallerPath);
        //Close the handle after using the it
        //so the garbage collector can delete the object associated with  it.
        skycoin.SKY_handle_close( configHandle );
      } else {
        // #Error
      }
    }
  }
}

Byte slices

Parameters of type byte[] will treated as string . Example, this function in Skycoin:

func (s ScryptChacha20poly1305) Encrypt(data, password []byte) ([]byte, error)

... should be invoked like this:

var encrypt_settings = new skycoin.encrypt__ScryptChacha20poly1305();
var data = new skycoin.GoSlice(); //It will be passed as a parameter of type []byte
var pwd = new skycoin.GoSlice(); //As []byte too
var dataStr = new skycoin._GoString();
var pwdStr = new skycoin._GoString();
var encrypted = new skycoin.GoSlice();

dataStr.setString("Data to encrypt" );
data.convertString(dataStr);
pwdStr.SetString("password");
pwd.convertString(pwdStr);

var err = skycoin.SKY_encrypt_ScryptChacha20poly1305_Encrypt(encrypt_settings, data, pwd,encrypted);
if(err == skycoin.SKY_OK){
  encrypted.getString().p); //Encrypted is GoSlice
}

Structures

Structures that are not exported as handles are treated like JS classes. In the previous example type ScryptChacha20poly1305 is created in JS like:

var encrypt_settings = new skycoin.encrypt__ScryptChacha20poly1305()

And passed as first parameter in call to SKY_encrypt_ScryptChacha20poly1305_Encrypt.

Fixed Sized Arrays

Parameters of fixed size array are wrapped in structures when called from JS.

Given these types in Skycoin and this exported function:

  type PubKey [33]byte
  type SecKey [32]byte

  func GenerateDeterministicKeyPair(seed []byte) (PubKey, SecKey)

This is a way to use them to write assertions in JS:

//Generates random seed
var data = new skycoin.GoSlice();
var err = skycoin.SKY_cipher_RandByte(32,data);


var pubkey = new skycoin.cipher_PubKey();
var seckey = new skycoin.cipher_SecKey();

err = skycoin.SKY_cipher_GenerateDeterministicKeyPair(data, pubkey,seckey);

In the example above pubkey and seckey are objects of an structure type containing a field named data holding the corresponding instance of PubKey and SecKey. Something like:

  cipher_PubKey struct{
    data [33]byte;
  } cipher_PubKey;

  cipher_SecKey struct{
    data [32]byte;
  } ;

Other Slices

Other slices of base type different from byte are indeed wrapped inside classes. Let's see how to call the following function:

func GenerateDeterministicKeyPairs(seed []byte, n int) []SecKey

In Javascript this how it should be used to generate a deterministic sequence of pairs of public / private keys given a random seed:

//Generates random seed
var seed = new skycoin.GoSlice();
var err = skycoin.SKY_cipher_RandByte(32,seed);
var seckeys = new skycoin.cipher__SecKeys();

err = skycoin.SKY_cipher_GenerateDeterministicKeyPairs(seed, 2,seckeys);

for(int i=0;i<seckeys.count,i++){
  var pubkey = new skycoin.cipher_PubKey();
  var seckey = new skycoin.cipher_SecKey();
  seckeys.getAt(seckey,i);

  skycoin.SKY_cipher_PubKeyFromSecKey(seckey, pubkey);
  err = skycoin.SKY_cipher_PubKey_Verify(pubkey);
}

Memory Management

Memory management is transparent to the user. Any object allocated inside the library is left to be managed by the JS garbage collector.

Make Rules

The following make rules are available after git checkout of this repository. They all require Skycoin to be checked out as a git submodule of libskycoin JS .

$ make help

install                        Build all libraries and tester
test                           Test all clients
test-node-client               Test node client
test-axios-client              Test axios client
build-axios-client             Build axios client
build-node-client              Build node client
build-node-tester              Build node client tester
build-axios-tester             Build tester
configure                      Configure build environment
build-libc                     Build libskycoin C client library
build-swig                     Generate Node C module from SWIG interfaces
build-libsky-shared            Build shared library including SWIG wrappers

Development setup

It is highly recommended for developers to setup their environment using the available Docker images. Read the LibJS Skycoin Docker docs for further details.

The project has two branches: master and develop.

• develop is the default branch and will always have the latest code. The submodule at gopath/src/github.com/skycoin/libskycoin has to be in sync with skycoin/libskycoin develop branch.
• master will always be equal to the current stable release on the website, and should correspond with the latest release tag. The submodule at gopath/src/github.com/skycoin/libskycoin has to be in sync with skycoin/libskycoin master branch.

Separate stable development branches will be created to work on releases for supporting the most recent stable version of Skycoin. The name of these branches should be the Skycoin major and minor version numbers followed by dev suffix e.g. 0.25dev. These branches may be forked out of either master or develop branches, and the submodule at gopath/src/github.com/skycoin/libskycoin has to be in sync with the corresponding tag of skycoin/libskycoin official repository.

Stable development branches are created most of the time for the following reasons:

• A Skycoin release increasing patch version number.
• Enhanced support and bug fixes for a version of LibJS Skycoin compiled against an stable version of Skycoin
• Backporting useful features added in develop.

Running tests

$ make test

Releases

Update the version

0. If the master branch has commits that are not in develop (e.g. due to a hotfix applied to master), merge master into develop (and fix any build or test failures)
1. Switch to a new release branch named release-X.Y.Z for preparing the release.
2. Ensure that the submodule at gopath/src/github.com/skycoin/libskycoin is in sync with respect to the corresponding tag in https://github.com/skycoin/libskycoin repository.
3. Run make build to make sure that the code base is up to date
4. Update CHANGELOG.md: move the "unreleased" changes to the version and add the date.
5. Follow the steps in pre-release testing
6. Make a PR merging the release branch into master
7. Review the PR and merge it
8. Update files in https://github.com/skycoin/repo-info/tree/master/repos/skycoin/remote for skycoin/skycoindev-js Docker image, adding a new file for the new version and adjusting any configuration text that may have changed
9. Tag the master branch with the version number. Version tags start with v, e.g. v0.20.0. Sign the tag. If you have your GPG key in github, creating a release on the Github website will automatically tag the release. It can be tagged from the command line with git tag -as v0.20.0 $COMMIT_ID, but Github will not recognize it as a "release".
10. Release builds are created and uploaded by travis. To do it manually, checkout the master branch and follow the create release builds instructions.
11. Checkout develop branch and bump package up to next dev version number.

Pre-release testing

Perform these actions before releasing:

make test

Creating release builds

Release builds should be created from master branch . After updating release version it is necessary to follow these steps

Requirements

Have installed the node-gyp for the creation of the package.

https://www.npmjs.com/package/node-gyp

Building

make build

Final results are placed in the lib/skycoin/build/Release/ folder.

LibJS Skycoin wrappers for the Skycoin client API

LibJS Skycoin contains different clients libraries generated using SWAGGER tools from the latest OpenApi Specification in the GitHub Repository of LibSkycoin.

Clients

Name	Swagger Generator
libsky-axios	typescript-axios
libsky-node	typescript-node

LibSky-Axios Client

LibSky-Axios is the client library generated using the typescript-axios Swagger generator.

Installation

Before installing, make sure you understand the choices available to install a NPM package . For instance, in case of installing NPM client tools the process would look like this, using npm install command.

npm install libsky-axios

Install from sources

Download the repository from http://github.com/simelo/libjs-skycoin.git. Execute (make build) to build the library. Then

npm install PATH_TO_REPOSITORY/lib/skyapi/axios

Usage

Once installed to your project you can use the library as in the example below.

"use strict";

let libsky = require('libsky-axios'); // Import the library

let clientConfig = new libsky.Configuration(); // Create a basic client configuration object

const nodeUrl = 'https://node.skycoin.net'; // Url to a Skycoin Node

let client = new libsky.DefaultApi(clientConfig, nodeUrl); // Create a client object

client.version().then( // Get version data from nodeUrl
    result => {
      console.log(result.data);
      // Print the Version Object in result.data
    }
);

LibSky-Node Client

LibSky-Node is the client library generated using the typescript-node Swagger generator.

Installation

Before installing, make sure you understand the choices available to install a NPM package . For instance, in case of installing NPM client tools the process would look like this, using npm install command.

npm install libsky-node

Install from sources

Download the repository from http://github.com/simelo/libjs-skycoin.git. Execute (make build) to build the library. Then

npm install PATH_TO_REPOSITORY/lib/skyapi/node

Usage

Once installed to your project you can use the library as in the example below.

"use strict";

let libsky = require('libsky-node'); // Import the library

const nodeUrl = 'https://node.skycoin.net'; // Url to a Skycoin Node

let client = new libsky.DefaultApi(nodeUrl); // Create a client object

client.version().then( // Get version data from nodeUrl
    result => {
      console.log(result.data);
      // Print the Version Object in result.data
    }
);