TestBlockchain

TestBlockchain is a cryptocurrency wallet imitation. This wallet is independent from any real blockchain, does not support any kind of decentralization and cryptography, and implement only part of original RPC methods. One of purposes of this project is a testing of some kind of integrations with real cryptocurrency wallets.

TestBlockchain is allows you imitate real blockchain with any number of wallets. You can set start balance of this wallets and set time period for blocks generation. Then you can connect to this wallets over JSON-RPC protocol (in exactly the same way as you would connect to real wallets) and create transactions, send coins, wait confirmations, etc. No any data will be persisted or sent somewhere, so after stopping of TestBlockchain and starting again new blockchain would be created.

Requirements

TestBlockchain require java 8 for running.

Using

It is possible to use TestBlockchain either with command line or with java API.

Command-line

Download from releases and unzip testblockchain-cli-VERSION.zip zip archive. Start blockchain with name BTC and two wallets at ports 10000 and 10001 and start balances 3 and 5.5 coins:

$ ./testblockchain.sh --name BTC --wallet 10000:3 --wallet 10001:5.5
21:18:38.470 [main] INFO  BTC - Prepare 2 wallets
21:18:38.526 [main] INFO  BTC - Creating JSON-RPC server at port 10000 with start balance 3.00000000
21:18:38.695 [main] INFO  BTC - Creating JSON-RPC server at port 10001 with start balance 5.50000000
21:18:38.696 [main] INFO  BTC - Creating HTTP server
21:18:38.764 [main] INFO  BTC - Starting blockchain with period 1000 millis for block generations
21:18:38.764 [main] INFO  BTC - Starting HTTP server
21:18:38.813 [main] INFO  BTC - Blockchain with 2 wallets started and ready to accept connections!

Create some transactions, for example by original Bitcoin Core client.

$ ./bitcoin-cli -rpcconnect=localhost -rpcport=10000 getbalance
3
$ ./bitcoin-cli -rpcconnect=localhost -rpcport=10001 getbalance
5.5
$ ./bitcoin-cli -rpcconnect=localhost -rpcport=10000 getnewaddress
a91f98f6c36e80b35cf620beed7be788
$ ./bitcoin-cli -rpcconnect=localhost -rpcport=10001 sendtoaddress a91f98f6c36e80b35cf620beed7be788 1.005
606b6f9ed61133036fa967ddf7e3ff610110ba7a03627c2a521bd95e0951900a
$ ./bitcoin-cli -rpcconnect=localhost -rpcport=10000 getbalance
4.005
$ ./bitcoin-cli -rpcconnect=localhost -rpcport=10001 getbalance
4.495

Available testblockchain CLI options:

Name	Long name	Required	Default value	Description
-n	--name	Yes		Coin name.
-w	--wallet	Yes		Wallet definition in <port:balance> format. Specify local TCP port and starting balance of wallet. This option can be used multiple times.
-bp	--block-period	No	1000	Block generation period in millis.
-v	--version	No		Print version and exit.
-h	--help	No		Print help and exit.

Java

Add repository to your POM:

	<repository>
		<id>indvd00m-github-repo</id>
		<url>https://github.com/indvd00m/maven-repo/raw/master/repository</url>
	</repository>

Add dependency to your maven project:

	<dependency>
		<groupId>com.indvd00m.testblockchain</groupId>
		<artifactId>wallet-impl</artifactId>
		<version>1.1.0</version>
	</dependency>

Create blockchain, wallets and some transactions:

	@Test
	public void test() throws InterruptedException {
		Blockchain blockchain = new BlockchainImpl(1000);
		Wallet wallet1 = new WalletImpl(blockchain, new BigDecimal("3"));
		Wallet wallet2 = new WalletImpl(blockchain, new BigDecimal("5.5"));
		blockchain.start();

		waitNextBlock(blockchain);

		assertEquals(0, wallet1.getbalance().compareTo(new BigDecimal("3")));
		assertEquals(0, wallet2.getbalance().compareTo(new BigDecimal("5.5")));

		String address1_1 = wallet1.getnewaddress();
		wallet2.sendtoaddress(address1_1, new BigDecimal("1.005"));
		waitNextBlock(blockchain);

		assertEquals(0, wallet1.getbalance().compareTo(new BigDecimal("4.005")));
		assertEquals(0, wallet2.getbalance().compareTo(new BigDecimal("4.495")));
	}

	protected void waitNextBlock(Blockchain blockchain) throws InterruptedException {
		int confirmations = blockchain.getConfirmations();
		while (confirmations == blockchain.getConfirmations()) {
			TimeUnit.MILLISECONDS.sleep(100);
		}
	}

See tests in module wallet-impl for more examples. For remote connecting over JSON-RPC protocol with jsonrpc4j see example in test TestCoinServer.

Implementation details

Supported JSON-RPC methods:

List of original RPC methods which now implemented:

Name	Notes
getaccount
getaccountaddress
getaddressesbyaccount
getbalance
getblock
getblockcount
getblockhash
getinfo
getnewaddress
getreceivedbyaccount
getreceivedbyaddress
gettransaction
listaccounts
listreceivedbyaccount
listreceivedbyaddress
listsinceblock
listtransactions
sendtoaddress
settxfee
validateaddress

Other methods will return -32001 or -32601 error codes. Behavior of some implemented methods may differ from original blockchain but as far as possible it repeats the original.

CI

Travis builds:

Download release

https://github.com/indvd00m/testblockchain/releases

Roadmap

This project is developed as a hobby with no public roadmap or any guarantees of upcoming releases.

Issue tracking

The issues for this project are tracked on its github.com page. All bug reports and feature requests are appreciated.

Building and running tests

git clone https://github.com/indvd00m/testblockchain/
cd testblockchain
mvn clean install

Contributions

Contributions are welcome, but there are no guarantees that they are accepted as such. Process for contributing is the following:

• Fork this project
• Create an issue to this project about the contribution (bug or feature) if there is no such issue about it already. Try to keep the scope minimal.
• Develop and test the fix or functionality carefully. Only include minimum amount of code needed to fix the issue.
• Refer to the fixed issue in commit
• Send a pull request for the original project
• Comment on the original issue that you have implemented a fix for it

License & Author

TestBlockchain is distributed under Apache License 2.0. For license terms, see LICENSE.

TestBlockchain is written by David E. Veliev.