DDevelopment & Design

Integration Tests for SMX4 with Python

Integration tests and unit tests are important for project quality. Unit tests usually are well suited for developer to verify his changes in runtime. On the other hand, integration tests, are for target user to verify that project’s features in the way he interacts with project, work properly. In this article, I will show how to automate integration tests for ServiceMix 4 using SoapUI testrunner and a simple python script.
The idea is to spawn ServiceMix 4 Karaf console and interact with it using python expect library. During this interaction, SoapUI testrunner script is invoked in order to run SoapUI tests.
First, we need to grab SMX4_DIR and SOAPUI_DIR environment variables in our script, like this:

SMX4_DIR=os.getenv("SMX4_DIR")
SOAPUI_DIR=os.getenv("SOAPUI_DIR")

 
This way, we can invoke later our script using following shell command:

SMX4_DIR=/some/path SOAPUI_DIR=/some/other/path ./our-python-script

 
Then, we need to spawn ServiceMix 4 console by using python expect library:

import pexpect
import time
import sys
child = pexpect.spawn("bin/servicemix")
child.logfile = sys.stdout
child.expect("karaf.*>")
time.sleep(3)

 
Here, we set logfile to stdout in order to see our automated interaction with ServiceMix console. Then we need to wait for ServiceMix console command prompt, which would mean console is ready. Additionally, we need to wait a few seconds to avoid problems with running commands too early (which is a kind of small bug in ServiceMix). Then, we can install our features, which we want to test. This example starts Apache HISE test bundle, which loads also Apache HISE engine from dependencies.

child.sendline("features:addUrl mvn:org.apache.hise/hise-karaf/0.3.0-SNAPSHOT/xml/features");
child.expect("karaf.*>")
child.sendline("features:install hise-h2-test-example-osgi")
child.expect("karaf.*>")

 
Next, we need to wait until the feature is properly started. ServiceMix 4 OSGi container initializes bundles in background, so it’s not enough to wait for command prompt to have it started (there doesn’t seem to exist a “wait-until-started” console command).So we grep in a loop over installed bundles and see if status is started. In this example, we do 30 retries every second and fail our integration test script after this period, by raising exception.

child.sendline("features:addUrl mvn:org.apache.hise/hise-karaf/0.3.0-SNAPSHOT/xml/features");
rep=0
while True:
    child.sendline("osgi:list|grep -i hise-test-example-osgi")
    l=child.readline()
    l=child.readline()
    if re.match(".*Started", l) != None:
        break
    time.sleep(1)
    child.expect("karaf.*>")
    rep=rep+1
    if rep>30:
        raise Exception("Bundle not installed")

 
Next, we need to run SoapUI testrunner in order to execute test cases. We need to implement syscall method in order to fail integration tests if SoapUI testrunner completes with fault (non-zero exit code).

import os
def syscall(c):
    if os.system(c) != 0:
        raise Exception("Sys call failed: " + c)

syscall(SOAPUI_DIR + “/bin/testrunner.sh -f results hise-soapui-project.xml”)
At the end, we can exit gracefully from ServiceMix console by using shutdown command, like this:

child.sendline("shutdown")

 

And that’s it. Full code of integration test script is available in Apache HISE sources, from Apache repository http://svn.apache.org/repos/asf/incubator/hise/trunk/itest/itest.

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DDevelopment & Design

Using WsLite in practice

TL;DR

There is a example working GitHub project which covers unit testing and request/response logging when using WsLite.

Why Groovy WsLite ?

I’m a huge fan of Groovy WsLite project for calling SOAP web services. Yes, in a real world you have to deal with those - big companies have huge amount of “legacy” code and are crazy about homogeneous architecture - only SOAP, Java, Oracle, AIX…

But I also never been comfortable with XFire/CXF approach of web service client code generation. I wrote a bit about other posibilites in this post. With JAXB you can also experience some freaky classloading errors - as Tomek described on his blog. In a large commercial project the “the less code the better” principle is significant. And the code generated from XSD could look kinda ugly - especially more complicated structures like sequences, choices, anys etc.

Using WsLite with native Groovy concepts like XmlSlurper could be a great choice. But since it’s a dynamic approach you have to be really careful - write good unit tests and log requests. Below are my few hints for using WsLite in practice.

Unit testing

Suppose you have some invocation of WsLite SOAPClient (original WsLite example):

def getMothersDay(long _year) {
    def response = client.send(SOAPAction: action) {
       body {
           GetMothersDay('xmlns':'http://www.27seconds.com/Holidays/US/Dates/') {
              year(_year)
           }
       }
    }
    response.GetMothersDayResponse.GetMothersDayResult.text()
}

How can the unit test like? My suggestion is to mock SOAPClient and write a simple helper to test that builded XML is correct. Example using great SpockFramework: 

void setup() {
   client = Mock(SOAPClient)
   service.client = client
}

def "should pass year to GetMothersDay and return date"() {
  given:
      def year = 2013
  when:
      def date = service.getMothersDay(year)
  then:
      1 * client.send(_, _) >> { Map params, Closure requestBuilder ->
            Document doc = buildAndParseXml(requestBuilder)
            assertXpathEvaluatesTo("$year", '//ns:GetMothersDay/ns:year', doc)
            return mockResponse(Responses.mothersDay)
      }
      date == "2013-05-12T00:00:00"
}

This uses a real cool feature of Spock - even when you mock the invocation with “any mark” (_), you are able to get actual arguments. So we can build XML that would be passed to SOAPClient's send method and check that specific XPaths are correct:

void setup() {
    engine = XMLUnit.newXpathEngine()
    engine.setNamespaceContext(new SimpleNamespaceContext(namespaces()))
}

protected Document buildAndParseXml(Closure xmlBuilder) {
    def writer = new StringWriter()
    def builder = new MarkupBuilder(writer)
    builder.xml(xmlBuilder)
    return XMLUnit.buildControlDocument(writer.toString())
}

protected void assertXpathEvaluatesTo(String expectedValue,
                                      String xpathExpression, Document doc) throws XpathException {
    Assert.assertEquals(expectedValue,
            engine.evaluate(xpathExpression, doc))
}

protected Map namespaces() {
    return [ns: 'http://www.27seconds.com/Holidays/US/Dates/']
}

The XMLUnit library is used just for XpathEngine, but it is much more powerful for comparing XML documents. The NamespaceContext is needed to use correct prefixes (e.g. ns:GetMothersDay) in your Xpath expressions.

Finally - the mock returns SOAPResponse instance filled with envelope parsed from some constant XML:

protected SOAPResponse mockResponse(String resp) {
    def envelope = new XmlSlurper().parseText(resp)
    new SOAPResponse(envelope: envelope)
}

Request and response logging

The WsLite itself doesn’t use any logging framework. We usually handle it by adding own sendWithLogging method:

private SOAPResponse sendWithLogging(String action, Closure cl) {
    SOAPResponse response = client.send(SOAPAction: action, cl)
    log(response?.httpRequest, response?.httpResponse)
    return response
}

private void log(HTTPRequest request, HTTPResponse response) {
    log.debug("HTTPRequest $request with content:\n${request?.contentAsString}")
    log.debug("HTTPResponse $response with content:\n${response?.contentAsString}")
}

This logs the actual request and response send through SOAPClient. But it logs only when invocation is successful and errors are much more interesting… So here goes withExceptionHandler method:

private SOAPResponse withExceptionHandler(Closure cl) {
    try {
        cl.call()
    } catch (SOAPFaultException soapEx) {
        log(soapEx.httpRequest, soapEx.httpResponse)
        def message = soapEx.hasFault() ? soapEx.fault.text() : soapEx.message
        throw new InfrastructureException(message)
    } catch (HTTPClientException httpEx) {
        log(httpEx.request, httpEx.response)
        throw new InfrastructureException(httpEx.message)
    }
}
def send(String action, Closure cl) {
    withExceptionHandler {
        sendWithLogging(action, cl)
    }
}

XmlSlurper gotchas

Working with XML document with XmlSlurper is generally great fun, but is some cases could introduce some problems. A trivial example is parsing an id with a number to Long value:

def id = Long.valueOf(edit.'@id' as String)

The Attribute class (which edit.'@id' evaluates to) can be converted to String using as operator, but converting to Long requires using valueOf.

The second example is a bit more complicated. Consider following XML fragment:

<edit id="3">
   <params>
      <param value="label1" name="label"/>
      <param value="2" name="param2"/>
   </params>
   <value>123</value>
</edit>
<edit id="6">
   <params>
      <param value="label2" name="label"/>
      <param value="2" name="param2"/>
   </params>
   <value>456</value>
</edit>

We want to find id of edit whose label is label1. The simplest solution seems to be:

def param = doc.edit.params.param.find { it['@value'] == 'label1' }
def edit = params.parent().parent()

But it doesn’t work! The parent method returns multiple edits, not only the one that is parent of given param…

Here’s the correct solution:

doc.edit.find { edit ->
    edit.params.param.find { it['@value'] == 'label1' }
}

Example

The example working project covering those hints could be found on GitHub.

DDevelopment & Design

Grails render as JSON catch

One of a reasons your controller doesn't render a proper response in JSON format might be wrong package name that you use. It is easy to overlook. Import are on top of a file, you look at your code and everything seems to be fine. Except response is still not in JSON format.

Consider this simple controller:

class RestJsonCatchController {
def grailsJson() {
render([first: 'foo', second: 5] as grails.converters.JSON)
    }

def netSfJson() {
render([first: 'foo', second: 5] as net.sf.json.JSON)
    }
}

And now, with finger crossed... We have a winner!

$ curl localhost:8080/example/restJsonCatch/grailsJson
{"first":"foo","second":5}
$ curl localhost:8080/example/restJsonCatch/netSfJson
{first=foo, second=5}

As you can see only grails.converters.JSON converts your response to JSON format. There is no such converter for net.sf.json.JSON, so Grails has no converter to apply and it renders Map normally.

Conclusion: always carefully look at your imports if you're working with JSON in Grails!

Edit: Burt suggested that this is a bug. I've submitted JIRA issue here: GRAILS-9622 render as class that is not a codec should throw exception