ExternalVendorCode/corda
1
0
Fork 0
mirror of https://github.com/corda/corda.git synced 2024-12-20 21:43:14 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity
98aac62a42
corda/docs/build/html/tutorial-test-dsl.html

741 lines
56 KiB
HTML
Raw Normal View History

Rebuild documentation
2016-07-12 16:52:52 +00:00
<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Writing a contract test &mdash; R3 Corda latest documentation</title>
<link rel="stylesheet" href="_static/css/custom.css" type="text/css" />
<link rel="top" title="R3 Corda latest documentation" href="index.html"/>
<link rel="next" title="Protocol state machines" href="protocol-state-machines.html"/>
<link rel="prev" title="Writing a contract using clauses" href="tutorial-contract-clauses.html"/>
<script src="_static/js/modernizr.min.js"></script>
</head>
<body class="wy-body-for-nav" role="document">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-scroll">
<div class="wy-side-nav-search">
<a href="index.html" class="icon icon-home"> R3 Corda
</a>
<div class="version">
latest
</div>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
<br>
<a href="api/index.html">API reference</a>
</div>
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
<p class="caption"><span class="caption-text">Overview</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="inthebox.html">What&#8217;s included?</a></li>
<li class="toctree-l1"><a class="reference internal" href="getting-set-up.html">Getting set up</a></li>
<li class="toctree-l1"><a class="reference internal" href="data-model.html">Data model</a></li>
<li class="toctree-l1"><a class="reference internal" href="transaction-data-types.html">Data types</a></li>
<li class="toctree-l1"><a class="reference internal" href="consensus.html">Consensus model</a></li>
<li class="toctree-l1"><a class="reference internal" href="messaging.html">Networking and messaging</a></li>
<li class="toctree-l1"><a class="reference internal" href="running-the-demos.html">Running the demos</a></li>
<li class="toctree-l1"><a class="reference internal" href="node-administration.html">Node administration</a></li>
<li class="toctree-l1"><a class="reference internal" href="irs.html">The Interest Rate Swap Contract</a></li>
</ul>
<p class="caption"><span class="caption-text">Tutorials</span></p>
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="where-to-start.html">Where to start</a></li>
<li class="toctree-l1"><a class="reference internal" href="tutorial-contract.html">Writing a contract</a></li>
<li class="toctree-l1"><a class="reference internal" href="tutorial-contract-clauses.html">Writing a contract using clauses</a></li>
<li class="toctree-l1 current"><a class="current reference internal" href="#">Writing a contract test</a><ul>
<li class="toctree-l2"><a class="reference internal" href="#testing-single-transactions">Testing single transactions</a></li>
<li class="toctree-l2"><a class="reference internal" href="#chaining-transactions">Chaining transactions</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="protocol-state-machines.html">Protocol state machines</a></li>
<li class="toctree-l1"><a class="reference internal" href="oracles.html">Writing oracle services</a></li>
<li class="toctree-l1"><a class="reference internal" href="event-scheduling.html">Event scheduling</a></li>
</ul>
<p class="caption"><span class="caption-text">Appendix</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="release-process.html">Release process</a></li>
<li class="toctree-l1"><a class="reference internal" href="release-process.html#steps-to-cut-a-release">Steps to cut a release</a></li>
<li class="toctree-l1"><a class="reference internal" href="release-notes.html">Release notes</a></li>
<li class="toctree-l1"><a class="reference internal" href="visualiser.html">Using the visualiser</a></li>
<li class="toctree-l1"><a class="reference internal" href="codestyle.html">Code style guide</a></li>
<li class="toctree-l1"><a class="reference internal" href="building-the-docs.html">Building the documentation</a></li>
</ul>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" role="navigation" aria-label="top navigation">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="index.html">R3 Corda</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="index.html">Docs</a> &raquo;</li>
<li>Writing a contract test</li>
<li class="wy-breadcrumbs-aside">
<a href="_sources/tutorial-test-dsl.txt" rel="nofollow"> View page source</a>
</li>
</ul>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<script type="text/javascript" src="_static/jquery.js"></script>
<script type="text/javascript" src="_static/codesets.js"></script><div class="section" id="writing-a-contract-test">
<h1>Writing a contract test<a class="headerlink" href="#writing-a-contract-test" title="Permalink to this headline"></a></h1>
<p>This tutorial will take you through the steps required to write a contract test using Kotlin and/or Java.</p>
<p>The testing DSL allows one to define a piece of the ledger with transactions referring to each other, and ways of
verifying their correctness.</p>
<div class="section" id="testing-single-transactions">
<h2>Testing single transactions<a class="headerlink" href="#testing-single-transactions" title="Permalink to this headline"></a></h2>
<p>We start with the empty ledger:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span><span class="n">@Test</span>
<span class="k">fun</span> <span class="nf">emptyLedger</span><span class="p">()</span> <span class="p">{</span>
<span class="n">ledger</span> <span class="p">{</span>
<span class="p">}</span>
<span class="p">}</span>
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">static</span> <span class="n">com</span><span class="o">.</span><span class="na">r3corda</span><span class="o">.</span><span class="na">core</span><span class="o">.</span><span class="na">testing</span><span class="o">.</span><span class="na">JavaTestHelpers</span><span class="o">.*;</span>
<span class="kn">import</span> <span class="nn">static</span> <span class="n">com</span><span class="o">.</span><span class="na">r3corda</span><span class="o">.</span><span class="na">core</span><span class="o">.</span><span class="na">contracts</span><span class="o">.</span><span class="na">JavaTestHelpers</span><span class="o">.*;</span>
<span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">emptyLedger</span><span class="o">()</span> <span class="o">{</span>
<span class="n">ledger</span><span class="o">(</span><span class="n">l</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span> <span class="c1">// We need to return this explicitly</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
<p>The DSL keyword <code class="docutils literal"><span class="pre">ledger</span></code> takes a closure that can build up several transactions and may verify their overall
correctness.</p>
<p>Let&#8217;s add a Cash transaction:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>@Test
fun simpleCashDoesntCompile() {
val inState = Cash.State(
amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1),
owner = DUMMY_PUBKEY_1
)
ledger {
transaction {
input(inState)
}
}
}
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">simpleCashDoesntCompile</span><span class="o">()</span> <span class="o">{</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inState</span> <span class="o">=</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">(</span>
<span class="n">issuedBy</span><span class="o">(</span><span class="n">DOLLARS</span><span class="o">(</span><span class="mi">1000</span><span class="o">),</span> <span class="n">getMEGA_CORP</span><span class="o">().</span><span class="na">ref</span><span class="o">((</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">,</span> <span class="o">(</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">)),</span>
<span class="n">getDUMMY_PUBKEY_1</span><span class="o">()</span>
<span class="o">);</span>
<span class="n">ledger</span><span class="o">(</span><span class="n">l</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">l</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="n">inState</span><span class="o">);</span>
<span class="o">});</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
<p>We can add a transaction to the ledger using the <code class="docutils literal"><span class="pre">transaction</span></code> primitive. The transaction in turn may be defined by
specifying <code class="docutils literal"><span class="pre">input</span></code>-s, <code class="docutils literal"><span class="pre">output</span></code>-s, <code class="docutils literal"><span class="pre">command</span></code>-s and <code class="docutils literal"><span class="pre">attachment</span></code>-s.</p>
<p>The above <code class="docutils literal"><span class="pre">input</span></code> call is a bit special: Transactions don&#8217;t actually contain input states, just references
to output states of other transactions. Under the hood the above <code class="docutils literal"><span class="pre">input</span></code> call creates a dummy transaction in the
ledger (that won&#8217;t be verified) which outputs the specified state, and references that from this transaction.</p>
<p>The above code however doesn&#8217;t compile:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span><span class="n">Error</span><span class="p">:(</span><span class="m">26</span><span class="p">,</span> <span class="m">21</span><span class="p">)</span> <span class="n">Kotlin</span><span class="p">:</span> <span class="n">Type</span> <span class="n">mismatch</span><span class="p">:</span> <span class="n">inferred</span> <span class="n">type</span> <span class="k">is</span> <span class="n">Unit</span> <span class="n">but</span> <span class="n">EnforceVerifyOrFail</span> <span class="n">was</span> <span class="n">expected</span>
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nl">Error:</span><span class="o">(</span><span class="mi">26</span><span class="o">,</span> <span class="mi">31</span><span class="o">)</span> <span class="n">java</span><span class="o">:</span> <span class="n">incompatible</span> <span class="n">types</span><span class="o">:</span> <span class="n">bad</span> <span class="k">return</span> <span class="n">type</span> <span class="n">in</span> <span class="n">lambda</span> <span class="n">expression</span> <span class="n">missing</span> <span class="k">return</span> <span class="n">value</span>
</pre></div>
</div>
</div>
<p>This is deliberate: The DSL forces us to specify either <code class="docutils literal"><span class="pre">this.verifies()</span></code> or <code class="docutils literal"><span class="pre">this</span> <span class="pre">`fails</span> <span class="pre">with`</span> <span class="pre">&quot;some</span> <span class="pre">text&quot;</span></code> on the
last line of <code class="docutils literal"><span class="pre">transaction</span></code>:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>@Test
fun simpleCash() {
val inState = Cash.State(
amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1),
owner = DUMMY_PUBKEY_1
)
ledger {
transaction {
input(inState)
this.verifies()
}
}
}
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">simpleCash</span><span class="o">()</span> <span class="o">{</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inState</span> <span class="o">=</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">(</span>
<span class="n">issuedBy</span><span class="o">(</span><span class="n">DOLLARS</span><span class="o">(</span><span class="mi">1000</span><span class="o">),</span> <span class="n">getMEGA_CORP</span><span class="o">().</span><span class="na">ref</span><span class="o">((</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">,</span> <span class="o">(</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">)),</span>
<span class="n">getDUMMY_PUBKEY_1</span><span class="o">()</span>
<span class="o">);</span>
<span class="n">ledger</span><span class="o">(</span><span class="n">l</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">l</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="n">inState</span><span class="o">);</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="o">});</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
<p>The code finally compiles. When run, it produces the following error:</p>
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>com.r3corda.core.contracts.TransactionVerificationException$ContractRejection: java.lang.IllegalArgumentException: Failed requirement: for deposit [0101] at issuer MegaCorp the amounts balance
</pre></div>
</div>
<p>The transaction verification failed, because the sum of inputs does not equal the sum of outputs. We can specify that
this is intended behaviour by changing <code class="docutils literal"><span class="pre">this.verifies()</span></code> to <code class="docutils literal"><span class="pre">this</span> <span class="pre">`fails</span> <span class="pre">with`</span> <span class="pre">&quot;the</span> <span class="pre">amounts</span> <span class="pre">balance&quot;</span></code>:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>@Test
fun simpleCashFailsWith() {
val inState = Cash.State(
amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1),
owner = DUMMY_PUBKEY_1
)
ledger {
transaction {
input(inState)
this `fails with` &quot;the amounts balance&quot;
}
}
}
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">simpleCashFailsWith</span><span class="o">()</span> <span class="o">{</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inState</span> <span class="o">=</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">(</span>
<span class="n">issuedBy</span><span class="o">(</span><span class="n">DOLLARS</span><span class="o">(</span><span class="mi">1000</span><span class="o">),</span> <span class="n">getMEGA_CORP</span><span class="o">().</span><span class="na">ref</span><span class="o">((</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">,</span> <span class="o">(</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">)),</span>
<span class="n">getDUMMY_PUBKEY_1</span><span class="o">()</span>
<span class="o">);</span>
<span class="n">ledger</span><span class="o">(</span><span class="n">l</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">l</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="n">inState</span><span class="o">);</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">failsWith</span><span class="o">(</span><span class="s">&quot;the amounts balance&quot;</span><span class="o">);</span>
<span class="o">});</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
<p>We can continue to build the transaction until it <code class="docutils literal"><span class="pre">verifies</span></code>:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>@Test
fun simpleCashSuccess() {
val inState = Cash.State(
amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1),
owner = DUMMY_PUBKEY_1
)
ledger {
transaction {
input(inState)
this `fails with` &quot;the amounts balance&quot;
output(inState.copy(owner = DUMMY_PUBKEY_2))
command(DUMMY_PUBKEY_1) { Cash.Commands.Move() }
this.verifies()
}
}
}
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">simpleCashSuccess</span><span class="o">()</span> <span class="o">{</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inState</span> <span class="o">=</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">(</span>
<span class="n">issuedBy</span><span class="o">(</span><span class="n">DOLLARS</span><span class="o">(</span><span class="mi">1000</span><span class="o">),</span> <span class="n">getMEGA_CORP</span><span class="o">().</span><span class="na">ref</span><span class="o">((</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">,</span> <span class="o">(</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">)),</span>
<span class="n">getDUMMY_PUBKEY_1</span><span class="o">()</span>
<span class="o">);</span>
<span class="n">ledger</span><span class="o">(</span><span class="n">l</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">l</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="n">inState</span><span class="o">);</span>
<span class="n">tx</span><span class="o">.</span><span class="na">failsWith</span><span class="o">(</span><span class="s">&quot;the amounts balance&quot;</span><span class="o">);</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="n">inState</span><span class="o">.</span><span class="na">copy</span><span class="o">(</span><span class="n">inState</span><span class="o">.</span><span class="na">getAmount</span><span class="o">(),</span> <span class="n">getDUMMY_PUBKEY_2</span><span class="o">()));</span>
<span class="n">tx</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getDUMMY_PUBKEY_1</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="o">});</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
<p><code class="docutils literal"><span class="pre">output</span></code> specifies that we want the input state to be transferred to <code class="docutils literal"><span class="pre">DUMMY_PUBKEY_2</span></code> and <code class="docutils literal"><span class="pre">command</span></code> adds the
<code class="docutils literal"><span class="pre">Move</span></code> command itself, signed by the current owner of the input state, <code class="docutils literal"><span class="pre">DUMMY_PUBKEY_1</span></code>.</p>
<p>We constructed a complete signed cash transaction from <code class="docutils literal"><span class="pre">DUMMY_PUBKEY_1</span></code> to <code class="docutils literal"><span class="pre">DUMMY_PUBKEY_2</span></code> and verified it. Note
how we left in the <code class="docutils literal"><span class="pre">fails</span> <span class="pre">with</span></code> line - this is fine, the failure will be tested on the partially constructed
transaction.</p>
<p>What should we do if we wanted to test what happens when the wrong party signs the transaction? If we simply add a
<code class="docutils literal"><span class="pre">command</span></code> it will ruin the transaction for good... Enter <code class="docutils literal"><span class="pre">tweak</span></code>:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>@Test
fun simpleCashTweakSuccess() {
val inState = Cash.State(
amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1),
owner = DUMMY_PUBKEY_1
)
ledger {
transaction {
input(inState)
this `fails with` &quot;the amounts balance&quot;
output(inState.copy(owner = DUMMY_PUBKEY_2))
tweak {
command(DUMMY_PUBKEY_2) { Cash.Commands.Move() }
this `fails with` &quot;the owning keys are the same as the signing keys&quot;
}
command(DUMMY_PUBKEY_1) { Cash.Commands.Move() }
this.verifies()
}
}
}
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">simpleCashTweakSuccess</span><span class="o">()</span> <span class="o">{</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inState</span> <span class="o">=</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">(</span>
<span class="n">issuedBy</span><span class="o">(</span><span class="n">DOLLARS</span><span class="o">(</span><span class="mi">1000</span><span class="o">),</span> <span class="n">getMEGA_CORP</span><span class="o">().</span><span class="na">ref</span><span class="o">((</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">,</span> <span class="o">(</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">)),</span>
<span class="n">getDUMMY_PUBKEY_1</span><span class="o">()</span>
<span class="o">);</span>
<span class="n">ledger</span><span class="o">(</span><span class="n">l</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">l</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="n">inState</span><span class="o">);</span>
<span class="n">tx</span><span class="o">.</span><span class="na">failsWith</span><span class="o">(</span><span class="s">&quot;the amounts balance&quot;</span><span class="o">);</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="n">inState</span><span class="o">.</span><span class="na">copy</span><span class="o">(</span><span class="n">inState</span><span class="o">.</span><span class="na">getAmount</span><span class="o">(),</span> <span class="n">getDUMMY_PUBKEY_2</span><span class="o">()));</span>
<span class="n">tx</span><span class="o">.</span><span class="na">tweak</span><span class="o">(</span><span class="n">tw</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tw</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getDUMMY_PUBKEY_2</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tw</span><span class="o">.</span><span class="na">failsWith</span><span class="o">(</span><span class="s">&quot;the owning keys are the same as the signing keys&quot;</span><span class="o">);</span>
<span class="o">});</span>
<span class="n">tx</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getDUMMY_PUBKEY_1</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="o">});</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
<p><code class="docutils literal"><span class="pre">tweak</span></code> creates a local copy of the transaction. This allows the local &#8220;ruining&#8221; of the transaction allowing testing
of different error conditions.</p>
<p>We now have a neat little test that tests a single transaction. This is already useful, and in fact testing of a single
transaction in this way is very common. There is even a shorthand toplevel <code class="docutils literal"><span class="pre">transaction</span></code> primitive that creates a
ledger with a single transaction:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>@Test
fun simpleCashTweakSuccessTopLevelTransaction() {
val inState = Cash.State(
amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1),
owner = DUMMY_PUBKEY_1
)
transaction {
input(inState)
this `fails with` &quot;the amounts balance&quot;
output(inState.copy(owner = DUMMY_PUBKEY_2))
tweak {
command(DUMMY_PUBKEY_2) { Cash.Commands.Move() }
this `fails with` &quot;the owning keys are the same as the signing keys&quot;
}
command(DUMMY_PUBKEY_1) { Cash.Commands.Move() }
this.verifies()
}
}
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">simpleCashTweakSuccessTopLevelTransaction</span><span class="o">()</span> <span class="o">{</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inState</span> <span class="o">=</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">(</span>
<span class="n">issuedBy</span><span class="o">(</span><span class="n">DOLLARS</span><span class="o">(</span><span class="mi">1000</span><span class="o">),</span> <span class="n">getMEGA_CORP</span><span class="o">().</span><span class="na">ref</span><span class="o">((</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">,</span> <span class="o">(</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">)),</span>
<span class="n">getDUMMY_PUBKEY_1</span><span class="o">()</span>
<span class="o">);</span>
<span class="n">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="n">inState</span><span class="o">);</span>
<span class="n">tx</span><span class="o">.</span><span class="na">failsWith</span><span class="o">(</span><span class="s">&quot;the amounts balance&quot;</span><span class="o">);</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="n">inState</span><span class="o">.</span><span class="na">copy</span><span class="o">(</span><span class="n">inState</span><span class="o">.</span><span class="na">getAmount</span><span class="o">(),</span> <span class="n">getDUMMY_PUBKEY_2</span><span class="o">()));</span>
<span class="n">tx</span><span class="o">.</span><span class="na">tweak</span><span class="o">(</span><span class="n">tw</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tw</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getDUMMY_PUBKEY_2</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tw</span><span class="o">.</span><span class="na">failsWith</span><span class="o">(</span><span class="s">&quot;the owning keys are the same as the signing keys&quot;</span><span class="o">);</span>
<span class="o">});</span>
<span class="n">tx</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getDUMMY_PUBKEY_1</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
</div>
<div class="section" id="chaining-transactions">
<h2>Chaining transactions<a class="headerlink" href="#chaining-transactions" title="Permalink to this headline"></a></h2>
<p>Now that we know how to define a single transaction, let&#8217;s look at how to define a chain of them:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>@Test
fun chainCash() {
ledger {
unverifiedTransaction {
output(&quot;MEGA_CORP cash&quot;) {
Cash.State(
amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1),
owner = MEGA_CORP_PUBKEY
)
}
}
transaction {
input(&quot;MEGA_CORP cash&quot;)
output(&quot;MEGA_CORP cash&quot;.output&lt;Cash.State&gt;().copy(owner = DUMMY_PUBKEY_1))
command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() }
this.verifies()
}
}
}
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">chainCash</span><span class="o">()</span> <span class="o">{</span>
<span class="n">ledger</span><span class="o">(</span><span class="n">l</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">l</span><span class="o">.</span><span class="na">unverifiedTransaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">,</span>
<span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">(</span>
<span class="n">issuedBy</span><span class="o">(</span><span class="n">DOLLARS</span><span class="o">(</span><span class="mi">1000</span><span class="o">),</span> <span class="n">getMEGA_CORP</span><span class="o">().</span><span class="na">ref</span><span class="o">((</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">,</span> <span class="o">(</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">)),</span>
<span class="n">getMEGA_CORP_PUBKEY</span><span class="o">()</span>
<span class="o">)</span>
<span class="o">);</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="n">l</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inputCash</span> <span class="o">=</span> <span class="n">l</span><span class="o">.</span><span class="na">retrieveOutput</span><span class="o">(</span><span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">.</span><span class="na">class</span><span class="o">,</span> <span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">copy</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">getAmount</span><span class="o">(),</span> <span class="n">getDUMMY_PUBKEY_1</span><span class="o">()));</span>
<span class="n">tx</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getMEGA_CORP_PUBKEY</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="o">});</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
<p>In this example we declare that <code class="docutils literal"><span class="pre">MEGA_CORP</span></code> has a thousand dollars but we don&#8217;t care where from, for this we can use
<code class="docutils literal"><span class="pre">unverifiedTransaction</span></code>. Note how we don&#8217;t need to specify <code class="docutils literal"><span class="pre">this.verifies()</span></code>.</p>
<p>The <code class="docutils literal"><span class="pre">output</span></code> cash was labelled with <code class="docutils literal"><span class="pre">&quot;MEGA_CORP</span> <span class="pre">cash&quot;</span></code>, we can subsequently referred to this other transactions, e.g.
by <code class="docutils literal"><span class="pre">input(&quot;MEGA_CORP</span> <span class="pre">cash&quot;)</span></code> or <code class="docutils literal"><span class="pre">&quot;MEGA_CORP</span> <span class="pre">cash&quot;.output&lt;Cash.State&gt;()</span></code>.</p>
<p>What happens if we reuse the output cash twice?</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>@Test
fun chainCashDoubleSpend() {
ledger {
unverifiedTransaction {
output(&quot;MEGA_CORP cash&quot;) {
Cash.State(
amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1),
owner = MEGA_CORP_PUBKEY
)
}
}
transaction {
input(&quot;MEGA_CORP cash&quot;)
output(&quot;MEGA_CORP cash&quot;.output&lt;Cash.State&gt;().copy(owner = DUMMY_PUBKEY_1))
command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() }
this.verifies()
}
transaction {
input(&quot;MEGA_CORP cash&quot;)
// We send it to another pubkey so that the transaction is not identical to the previous one
output(&quot;MEGA_CORP cash&quot;.output&lt;Cash.State&gt;().copy(owner = DUMMY_PUBKEY_2))
command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() }
this.verifies()
}
}
}
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">chainCashDoubleSpend</span><span class="o">()</span> <span class="o">{</span>
<span class="n">ledger</span><span class="o">(</span><span class="n">l</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">l</span><span class="o">.</span><span class="na">unverifiedTransaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">,</span>
<span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">(</span>
<span class="n">issuedBy</span><span class="o">(</span><span class="n">DOLLARS</span><span class="o">(</span><span class="mi">1000</span><span class="o">),</span> <span class="n">getMEGA_CORP</span><span class="o">().</span><span class="na">ref</span><span class="o">((</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">,</span> <span class="o">(</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">)),</span>
<span class="n">getMEGA_CORP_PUBKEY</span><span class="o">()</span>
<span class="o">)</span>
<span class="o">);</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="n">l</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inputCash</span> <span class="o">=</span> <span class="n">l</span><span class="o">.</span><span class="na">retrieveOutput</span><span class="o">(</span><span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">.</span><span class="na">class</span><span class="o">,</span> <span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">copy</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">getAmount</span><span class="o">(),</span> <span class="n">getDUMMY_PUBKEY_1</span><span class="o">()));</span>
<span class="n">tx</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getMEGA_CORP_PUBKEY</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="o">});</span>
<span class="n">l</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inputCash</span> <span class="o">=</span> <span class="n">l</span><span class="o">.</span><span class="na">retrieveOutput</span><span class="o">(</span><span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">.</span><span class="na">class</span><span class="o">,</span> <span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="c1">// We send it to another pubkey so that the transaction is not identical to the previous one</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">copy</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">getAmount</span><span class="o">(),</span> <span class="n">getDUMMY_PUBKEY_2</span><span class="o">()));</span>
<span class="n">tx</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getMEGA_CORP_PUBKEY</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="o">});</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
<p>The transactions <code class="docutils literal"><span class="pre">verifies()</span></code> individually, however the state was spent twice!</p>
<p>We can also verify the complete ledger by calling <code class="docutils literal"><span class="pre">verifies</span></code>/<code class="docutils literal"><span class="pre">fails</span></code> on the ledger level. We can also use
<code class="docutils literal"><span class="pre">tweak</span></code> to create a local copy of the whole ledger:</p>
<div class="codeset container">
<div class="highlight-kotlin"><div class="highlight"><pre><span></span>@Test
fun chainCashDoubleSpendFailsWith() {
ledger {
unverifiedTransaction {
output(&quot;MEGA_CORP cash&quot;) {
Cash.State(
amount = 1000.DOLLARS `issued by` MEGA_CORP.ref(1, 1),
owner = MEGA_CORP_PUBKEY
)
}
}
transaction {
input(&quot;MEGA_CORP cash&quot;)
output(&quot;MEGA_CORP cash&quot;.output&lt;Cash.State&gt;().copy(owner = DUMMY_PUBKEY_1))
command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() }
this.verifies()
}
tweak {
transaction {
input(&quot;MEGA_CORP cash&quot;)
// We send it to another pubkey so that the transaction is not identical to the previous one
output(&quot;MEGA_CORP cash&quot;.output&lt;Cash.State&gt;().copy(owner = DUMMY_PUBKEY_1))
command(MEGA_CORP_PUBKEY) { Cash.Commands.Move() }
this.verifies()
}
this.fails()
}
this.verifies()
}
}
</pre></div>
</div>
<div class="highlight-java"><div class="highlight"><pre><span></span><span class="nd">@Test</span>
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">chainCashDoubleSpendFailsWith</span><span class="o">()</span> <span class="o">{</span>
<span class="n">ledger</span><span class="o">(</span><span class="n">l</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">l</span><span class="o">.</span><span class="na">unverifiedTransaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">,</span>
<span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">(</span>
<span class="n">issuedBy</span><span class="o">(</span><span class="n">DOLLARS</span><span class="o">(</span><span class="mi">1000</span><span class="o">),</span> <span class="n">getMEGA_CORP</span><span class="o">().</span><span class="na">ref</span><span class="o">((</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">,</span> <span class="o">(</span><span class="kt">byte</span><span class="o">)</span><span class="mi">1</span><span class="o">)),</span>
<span class="n">getMEGA_CORP_PUBKEY</span><span class="o">()</span>
<span class="o">)</span>
<span class="o">);</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="n">l</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inputCash</span> <span class="o">=</span> <span class="n">l</span><span class="o">.</span><span class="na">retrieveOutput</span><span class="o">(</span><span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">.</span><span class="na">class</span><span class="o">,</span> <span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">copy</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">getAmount</span><span class="o">(),</span> <span class="n">getDUMMY_PUBKEY_1</span><span class="o">()));</span>
<span class="n">tx</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getMEGA_CORP_PUBKEY</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="o">});</span>
<span class="n">l</span><span class="o">.</span><span class="na">tweak</span><span class="o">(</span><span class="n">lw</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">lw</span><span class="o">.</span><span class="na">transaction</span><span class="o">(</span><span class="n">tx</span> <span class="o">-&gt;</span> <span class="o">{</span>
<span class="n">tx</span><span class="o">.</span><span class="na">input</span><span class="o">(</span><span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="n">Cash</span><span class="o">.</span><span class="na">State</span> <span class="n">inputCash</span> <span class="o">=</span> <span class="n">l</span><span class="o">.</span><span class="na">retrieveOutput</span><span class="o">(</span><span class="n">Cash</span><span class="o">.</span><span class="na">State</span><span class="o">.</span><span class="na">class</span><span class="o">,</span> <span class="s">&quot;MEGA_CORP cash&quot;</span><span class="o">);</span>
<span class="c1">// We send it to another pubkey so that the transaction is not identical to the previous one</span>
<span class="n">tx</span><span class="o">.</span><span class="na">output</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">copy</span><span class="o">(</span><span class="n">inputCash</span><span class="o">.</span><span class="na">getAmount</span><span class="o">(),</span> <span class="n">getDUMMY_PUBKEY_2</span><span class="o">()));</span>
<span class="n">tx</span><span class="o">.</span><span class="na">command</span><span class="o">(</span><span class="n">getMEGA_CORP_PUBKEY</span><span class="o">(),</span> <span class="k">new</span> <span class="n">Cash</span><span class="o">.</span><span class="na">Commands</span><span class="o">.</span><span class="na">Move</span><span class="o">());</span>
<span class="k">return</span> <span class="n">tx</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="o">});</span>
<span class="n">lw</span><span class="o">.</span><span class="na">fails</span><span class="o">();</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="n">l</span><span class="o">.</span><span class="na">verifies</span><span class="o">();</span>
<span class="k">return</span> <span class="n">Unit</span><span class="o">.</span><span class="na">INSTANCE</span><span class="o">;</span>
<span class="o">});</span>
<span class="o">}</span>
</pre></div>
</div>
</div>
</div>
</div>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="protocol-state-machines.html" class="btn btn-neutral float-right" title="Protocol state machines" accesskey="n">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="tutorial-contract-clauses.html" class="btn btn-neutral" title="Writing a contract using clauses" accesskey="p"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<p>
&copy; Copyright 2016, Distributed Ledger Group, LLC.
</p>
</div>
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT:'./',
VERSION:'latest',
COLLAPSE_INDEX:false,
FILE_SUFFIX:'.html',
HAS_SOURCE: true
};
</script>
<script type="text/javascript" src="_static/jquery.js"></script>
<script type="text/javascript" src="_static/underscore.js"></script>
<script type="text/javascript" src="_static/doctools.js"></script>
<script type="text/javascript" src="_static/js/theme.js"></script>
<script type="text/javascript">
jQuery(function () {
SphinxRtdTheme.StickyNav.enable();
});
</script>
</body>
</html>
Reference in New Issue Copy Permalink