title: Regex in SoapUi's "Contains" assertion causes the assertion to always fail?
body: <p>I am using SoapUi 5.5.0 to create functional tests for my REST webservice. My project can already make REST requests and display the JSON response. Now I need to make an assertion about this response. But I can't get my assertion to work the way I want to. </p>
  
  <p>For the sake of example, lets say that I want to assert that the JSON response contains either the string "args" or "brgs". If the JSON contains either/both of these strings, the assertion will pass; otherwise the assertion will fail. To accomplish this, I open my "REST Request" test step and add a new "Contains" assertion. I configure the assertion to check whether the JSON response contains a match to the regex "[ab]rgs". </p>
  
  <p>After executing the REST Request, I can see that the JSON response contains (among other things) the string <code>"args": {},</code>. I expected my regex "Contains" assertion to pass at this point. But the assertion still says it failed. The assertion always fails. I cannot get a single regex "Contains" assertion to pass. Am I fundamentally misunderstanding how SoapUi works? or is the program bugging out?</p>
  
  <p>For your reference, here is the JSON response of the REST endpoint I'm testing against:</p>
  
  <pre><code>{
     "args": {},
     "headers":    {
        "Accept-Encoding": "gzip,deflate",
        "Host": "httpbin.org",
        "User-Agent": "Apache-HttpClient/4.1.1 (java 1.5)"
     },
     "origin": "199.82.243.104, 199.82.243.104",
     "url": "https://httpbin.org/get"
  }
  </code></pre>
  
  <p>Here is a picture of the configuration of my "Contains" assertion:
  <a href="https://i.stack.imgur.com/8tMCB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8tMCB.png" alt="assertion configuration"></a></p>
  
  <p>Here is my entire SoapUi project file:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;con:soapui-project id="ee46fa47-c454-437d-82a3-1b61154f78ea" activeEnvironment="Default" name="REST Project 1" resourceRoot="" soapui-version="5.5.0" abortOnError="false" runType="SEQUENTIAL" xmlns:con="http://eviware.com/soapui/config"&gt;
      &lt;con:settings/&gt;
      &lt;con:interface xsi:type="con:RestService" id="a6af7b2e-3c2a-4419-8524-141b5cbe02b5" wadlVersion="http://wadl.dev.java.net/2009/02" name="https://httpbin.org" type="rest" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;
          &lt;con:settings/&gt;
          &lt;con:definitionCache type="TEXT" rootPart=""/&gt;
          &lt;con:endpoints&gt;
              &lt;con:endpoint&gt;https://httpbin.org&lt;/con:endpoint&gt;
          &lt;/con:endpoints&gt;
          &lt;con:resource name="Get" path="/get" id="29a38000-2a32-420a-b33e-f978cc1bd088"&gt;
              &lt;con:settings/&gt;
              &lt;con:parameters/&gt;
              &lt;con:method name="Get 1" id="8d40ae42-98f1-4bcb-8247-7fdfad1415d6" method="GET"&gt;
                  &lt;con:settings/&gt;
                  &lt;con:parameters/&gt;
                  &lt;con:representation type="RESPONSE"&gt;
                      &lt;con:mediaType&gt;application/json&lt;/con:mediaType&gt;
                      &lt;con:status&gt;200&lt;/con:status&gt;
                      &lt;con:params/&gt;
                      &lt;con:element xmlns:get="https://httpbin.org/get"&gt;get:Response&lt;/con:element&gt;
                  &lt;/con:representation&gt;
                  &lt;con:request name="Request 1" id="f5c85bda-524b-4d2f-baf7-635f88774a17" mediaType="application/json"&gt;
                      &lt;con:settings&gt;
                          &lt;con:setting id="com.eviware.soapui.impl.wsdl.WsdlRequest@request-headers"&gt;&amp;lt;xml-fragment/&gt;&lt;/con:setting&gt;
                      &lt;/con:settings&gt;
                      &lt;con:endpoint&gt;https://httpbin.org&lt;/con:endpoint&gt;
                      &lt;con:request/&gt;
                      &lt;con:originalUri&gt;https://httpbin.org/get&lt;/con:originalUri&gt;
                      &lt;con:credentials&gt;
                          &lt;con:authType&gt;No Authorization&lt;/con:authType&gt;
                      &lt;/con:credentials&gt;
                      &lt;con:jmsConfig JMSDeliveryMode="PERSISTENT"/&gt;
                      &lt;con:jmsPropertyConfig/&gt;
                      &lt;con:parameters/&gt;
                  &lt;/con:request&gt;
              &lt;/con:method&gt;
          &lt;/con:resource&gt;
      &lt;/con:interface&gt;
      &lt;con:testSuite id="6cd7e9db-fb93-4f99-a47c-f0b9a0450e16" name="TestSuite 1"&gt;
          &lt;con:settings/&gt;
          &lt;con:runType&gt;SEQUENTIAL&lt;/con:runType&gt;
          &lt;con:testCase id="3b79550c-f88b-455e-9c26-008971a68641" failOnError="true" failTestCaseOnErrors="true" keepSession="false" maxResults="0" name="TestCase 1" searchProperties="true"&gt;
              &lt;con:settings/&gt;
              &lt;con:testStep type="restrequest" name="REST Request" id="2ada1bc8-3541-4918-a937-d83de9b2e395"&gt;
                  &lt;con:settings/&gt;
                  &lt;con:config service="https://httpbin.org" methodName="Get 1" resourcePath="/get" xsi:type="con:RestRequestStep" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;
                      &lt;con:restRequest name="REST Request" id="d17f2536-e9a3-4ddb-ad93-08db2e4a5551" mediaType="application/json"&gt;
                          &lt;con:settings&gt;
                              &lt;con:setting id="com.eviware.soapui.impl.wsdl.WsdlRequest@request-headers"&gt;&amp;lt;xml-fragment/&gt;&lt;/con:setting&gt;
                          &lt;/con:settings&gt;
                          &lt;con:encoding&gt;UTF-8&lt;/con:encoding&gt;
                          &lt;con:endpoint&gt;https://httpbin.org&lt;/con:endpoint&gt;
                          &lt;con:request/&gt;
                          &lt;con:originalUri&gt;https://httpbin.org/get&lt;/con:originalUri&gt;
                          &lt;con:assertion type="Simple Contains" id="8e6831f2-a067-4dc5-9ba7-163a73dd003b" name="Contains"&gt;
                              &lt;con:configuration&gt;&lt;token&gt;[ab]rgs&lt;/token&gt;&lt;ignoreCase&gt;false&lt;/ignoreCase&gt;&lt;useRegEx&gt;true&lt;/useRegEx&gt;&lt;/con:configuration&gt;
                          &lt;/con:assertion&gt;
                          &lt;con:credentials&gt;
                              &lt;con:authType&gt;No Authorization&lt;/con:authType&gt;
                          &lt;/con:credentials&gt;
                          &lt;con:jmsConfig JMSDeliveryMode="PERSISTENT"/&gt;
                          &lt;con:jmsPropertyConfig/&gt;
                          &lt;con:parameters/&gt;
                      &lt;/con:restRequest&gt;
                  &lt;/con:config&gt;
              &lt;/con:testStep&gt;
              &lt;con:properties/&gt;
          &lt;/con:testCase&gt;
          &lt;con:properties/&gt;
      &lt;/con:testSuite&gt;
      &lt;con:properties/&gt;
      &lt;con:wssContainer/&gt;
      &lt;con:oAuth2ProfileContainer/&gt;
      &lt;con:oAuth1ProfileContainer/&gt;
  &lt;/con:soapui-project&gt;
  </code></pre>
  
  <p>Thanks for the help.</p>