Citrus

See the following sample showing how to write a Citrus test on top of TestNG:

If you are familiar with TestNG you will see that the Java class is a normal TestNG test class using the usual @Test annotation. For convenience reasons you can extend a basic Citrus TestNG base class TestNGCitrusSupport which enables the Citrus test execution as well as the Java DSL features for us.

In addition, the test methods use the @CitrusTest annotation which allows setting properties such as test names and packages.

The Citrus test logic goes directly as the method body with using the Citrus Java domain specific language features. As you can see the Java DSL is able to follow BDD (Behavior Drive Design) principles with Given-When-Then syntax. As an alternative to that you can just use run() for all test actions.

The great news is that you can still use the awesome TestNG features in with the Citrus test class (e.g. parallel test execution, test groups, setup and tear down operations and so on). Just to give an example we can simply add a test group to our test like this:

For more information on TestNG please visit the official TestNG website, where you find a complete reference documentation. The following sections deal with a subset of these TestNG features in particular.

TestNG as a framework comes with lots of great features such as data providers. Data providers execute a test case several times with different test data. Each test execution works with a specific parameter value. You can use data provider parameter values as test variables in Citrus. See the next listing on how to use TestNG data providers in Citrus:

Above test case method is annotated with TestNG data provider called messageDataProvider . In the same class you can write the data provider that returns a list of parameter values. TestNG will execute the test case several times according to the provided parameter list. Each execution is shipped with the respective parameter value.

According to the @CitrusParameter annotation the test will have test variables called message and delay.

Integration tests tend to be more time-consuming compared to pure unit tests when it comes to execute tests. This is because integration tests often need to initialize test infrastructure (e.g. test servers, database connections). Running tests in parallel can reduce the overall test suite time a lot.

When running tests in parallel you need to make sure each test operates on its own set of resources. Tests must not share components such as the Citrus Java DSL test action runner or the test context.

You should be using the resource injection to make sure each test operates on its own resources.

First of all the method parameters must be annotated with @Optional because the values are not injected by TestNG itself but by the Citrus base test class. Finally, the parameter requires the @CitrusResource annotations in order to mark the parameter for Citrus resource injection.

Now each method uses its own resource instances which makes sure that parallel test execution can take place without having the risk of side effects on other tests running at the same time. Of course, you also need to make sure that the message exchange in your tests is ready to be performed in parallel (e.g. use message selectors).

You can use the Citrus JUnit5 extension on your test as follows:

The class above is using the JUnit5 @Test annotation as a normal unit test would do. The @CitrusSupport annotation marks the test to use the Citrus JUnit5 extension. This enables us to use the @CitrusTest annotation on the test and adds support for the parameter injection for the TestActionRunner.

The Citrus Java DSL runner is the entrance to the Java fluent API provided by Citrus. The sample above uses the Gherkin test runner variation for leveraging the BDD (Behavior Driven Development) style Given-When-Then syntax.

You can also inject the current TestContext in order to get access to the current test variables used by Citrus.

In addition to injecting test resources you can also inject endpoints via @CitrusEndpoint annotated field injection in your test class. This enabled you to inject endpoint components that are defined in the Citrus context configuration.

Spring is a famous dependency injection framework that also provides support for JUnit5. Citrus is able to load its components as Spring beans in an application context. The Citrus JUnit5 extension works great with the Spring extension.

The Spring extension loads the application context and Citrus adds all components to the Spring bean configuration.

The test now uses the @CitrusSpringSupport annotation which combines the @ExtendsWith(CitrusSpringExtension.class) and @ExtendsWith(SpringExtension.class) annotation. This way the test combines the Spring application context management with the Citrus Java DSL functionality.

You can load Spring beans with @Autowired into your test. Also you can use the @CitrusResource annotations to inject the test action runner fluent Java API.

See the following sample test class that uses JUnit4.

The simple test class above uses the normal @Test annotation and extends the base class JUnit4CitrusSupport. This is the most convenient way to access the Citrus Java DSL capabilities. As an alternative you may switch to using the CitrusJUnit4Runner in your test class.

The fine thing here is that we are still able to use all JUnit features such as before/after hooks or ignoring tests.

After the test run the result is reported exactly like a usual JUnit unit test would do. This also means that you can execute this Citrus JUnit class like every other JUnit test, especially out of any Java IDE, with Maven, with Gradle and so on.

Integration tests tend to be more time-consuming compared to pure unit tests when it comes to execute tests. This is because integration tests often need to initialize test infrastructure (e.g. test servers, database connections). Running tests in parallel can reduce the overall test suite time a lot.

When running tests in parallel you need to make sure each test operates on its own set of resources. Tests must not share components such as the Citrus Java DSL test action runner or the test context.

You should be using the resource injection to make sure each test operates on its own resources.

The method parameters require the @CitrusResource annotations in order to mark the parameter for Citrus resource injection.

Now each method uses its own resource instances which makes sure that parallel test execution can take place without having the risk of side effects on other tests running at the same time. Of course, you also need to make sure that the message exchange in your tests is ready to be performed in parallel (e.g. use message selectors).

Cucumber is able to run tests with JUnit. The basic test case is an empty test which uses the respective JUnit runner implementation from cucumber.

The test case above uses the Cucumber JUnit test runner. In addition to that we give some options to the Cucumber execution. In case you want to have the usual Citrus test results reported you can add the special Citrus reporter implementation com.consol.citrus.cucumber.CitrusReporter. This class is responsible for printing the Citrus test summary. This reporter extends the default Cucumber reporter so the default Cucumber report summary is also printed to the console.

That completes the JUnit class configuration. Now we are able to add feature stories and step definitions to the package of our test MyFeatureIT . Cucumber and Citrus will automatically pick up step definitions and glue code in that test package. So lets write a feature story echo.feature right next to the MyFeatureIT test class.

As you can see this story defines two scenarios with the Gherkin Given-When-Then syntax. Now we need to add step definitions that glue the story description to Citrus test actions. Lets do this in a new class EchoSteps .

The step definition class is a normal POJO that uses a some annotations such as @CitrusResource annotated TestCaseRunner. The Citrus backend injects the test runner instance at runtime.

The step definition contains normal @Given, @When or @Then annotated methods that match the scenario descriptions in our feature file. Cucumber will automatically find matching methods and execute them. The methods add test actions to the test runner as we used to do in normal Java DSL tests.

That is a first combination of Citrus and Cucumber BDD. The feature file gets translated into step implementations that use Citrus test action runner Java API to run integration tests with behavior driven development.

The previous section handled glue code in Java in in form of step definitions accessing the Java test runner fluent API. This chapter deals with the same concept with just XML configuration.

Citrus provides a separate configuration namespace and schema definition for Cucumber related step definitions. Include this namespace into your Spring configuration in order to use the Citrus Cucumber configuration elements.

The JUnit Cucumber feature class itself does not change. We still use the Cucumber JUnit runner implementation with some options specific to Citrus:

The feature file with its Gherkin scenarios does also not change:

In the feature package my.company.features we add a new XML file EchoSteps.xml that holds the new XML step definitions:

The above step definition uses pure XML actions. Citrus will automatically read the step definition and add those to the Cucumber runtime. Following from that the step definitions are executed when matching a statement in the feature story.

The XML step files follow a naming convention. Citrus will look for all files located in the feature package with name pattern **/**.Steps.xml and load those definitions when Cucumber starts up.

The XML steps are able to receive parameters from the Gherkin regexp matcher. The parameters are passed to the step as test variable. The parameter names get declared in the optional attribute parameter-names. In the step definitions you can use the parameter names as test variables.

We have to do this because otherwise the quotation characters will interfere with the XML syntax in the attribute.

This completes the description of how to add XML step definitions to the cucumber BDD tests.

Cucumber provides support for Spring dependency injection in step definition classes. The Cucumber Spring capabilities are included in a separate module. So we first of all we have to add this dependency to our project:

The Citrus Cucumber extension has to handle things different when Cucumber Spring support is enabled. Therefore we use another object factory implementation that also support Cucumber Spring features. Change the object factory property in cucumber.properties to the following:

Now we are ready to add @Autowired Spring bean dependency injection to step definition classes:

As you can see we used Spring autowiring mechanism for the echoEndpoint field in the step definition. Also be sure to define the @ContextConfiguration annotation on the step definition. The Cucumber Spring support loads the Spring application context and takes care on dependency injection. We use the Citrus CitrusSpringConfig Java configuration because this is the main entrance for Citrus test cases. You can add custom beans and further Spring related configuration to this Spring application context. If you want to add more beans for autowiring do so in the Citrus Spring configuration. Usually this is the default citrus-context.xml which is automatically loaded.

Of course, you can also use a custom Java Spring configuration class here. Please be sure to always import the Citrus Spring Java configuration classes, too.

As usual, we are able to use @CitrusResource annotated TestCaseRunner fields for building the Citrus integration test logic. With this extension you can use the full Spring testing power in your tests in particular dependency injection and also transaction management for data persistence tests.

YAKS is a side project of Citrus and provides some predefined steps for typical integration test scenarios that you can use out-of-the-box.

You can basically define send/receive operations and many other predefined steps to handle Citrus test actions. As these steps are predefined in YAKS you just need to use them in your feature stories. The step definitions with glue to test actions is handled automatically in YAKS.

If you want to enable predefined steps support in your test you need to include the YAKS module as a Maven dependency.

After that you need to include the glue code package in your test class like this:

Instead of writing the glue code on our own in step definition classes we include the glue package org.citrusframework.yaks.standard as extra glue. This automatically loads all YAKS step definitions in this module. Once you have done this you can use predefined steps without having to write any glue code in Java.

The YAKS framework provides the following modules with predefined steps:

Once again it should be said that the step definitions included in this modules can be used out-of-the-box. You can start to write feature stories in Gherkin syntax that trigger the predefined steps.

You can access the Citrus framework instance in order to access all components and functionalities. Just use the @CitrusFramework annotation in your test class.

The framework instance provides access to the Citrus context which is a central registry for all components. The example above adds a new message listener.

The test action runner is the entry to the fluent Java API. You can inject the runner as a method parameter.

The parameter requires the @CitrusResource annotations in order to mark the parameter for Citrus resource injection.

Now each method uses its own runner instances which makes sure that parallel test execution can take place without having the risk of side effects on other tests running at the same time.

The Citrus test context combines a set of central objects and functionalities that a test is able to make use of. The test context holds all variables and is able to resolve functions and validation matchers.

In general a tester will not have to explicitly access the test context because the framework is working with it behind the scenes. In terms of advanced operations and customizations accessing the test context may be a good idea though.

Each test action implementation has access to the test context as it is provided to the execution method in the interface:

In addition Citrus provides a resource injection mechanism that allows to access the current test context in a test class or test method.

As you can see the tst method defines a parameter of type com.consol.citrus.context.TestContext. The annotation @CitrusResource tells Citrus to inject this parameter with the according instance of the context for this test.

Now you have access to the context and all its capabilities such as variable management. As an alternative you can inject the test context as a class member variable.

Endpoints play a significant role when sending/receiving messages over various transports. An endpoint defines how to connect to a message transport (e.g. Http endpoint URL, JMS mesage broker connection, Kafka connection and topic selection).

Endpoints can live inside the Citrus context (e.g. in SPring application context) or you can inject the endpoint into the test class with given configuration.

The sample above creates a new endpoint as a direct in-memory channel endpoint. Citrus reads the @CitrusEndpoint annotation and adds the configuration as given in the @DirectEndpointConfig annotation. This way you can create and inject endpoints directly to your test.

When an incoming message is passing the message validation the user can extract some values of that received message to new test variables for later use in the test.

With this example we have extracted three new test variables via JSONPath expression evaluation. The three test variables will be available to all upcoming test actions. The variable values are:

As you can see we can also extract complex JSONObject items or JSONArray items. The test variable value is a String representation of the complex object.

Add this code to your message receiving action.

As you can see Citrus is able to extract both header and message body content into test variables. The extraction will automatically create a new variable in case it does not exist. The time the variable was created all following test actions can access the test variables as usual. So you can reference the variable values in response messages or other test steps ahead.

First thing we want to do with JsonPath is to manipulate a message content before it is actually processed. This is very useful when working with message file resources that are reused across multiple test cases. Each test case can manipulate the message content individually with JsonPath before processing the message content.

Let’s have a look at this simple sample Json message body:

Citrus can load the file content and used it as message body when sending or receiving messages in a test case. You can apply JsonPath expressions in order to manipulate the message content.

When all path expressions are evaluated the resulting message looks like follows:

The JsonPath expressions set the username to Admin . The admin boolean property was set to true and all project status values were set to closed. In case a JsonPath expression should fail to find a matching element within the message structure the test case will fail.

With this JsonPath mechanism ou are able to manipulate message content before it is sent or received within Citrus. This makes life very easy when using message resource files that are reused across multiple test cases.

In case of XML message bodies you can use XPath expressions to manipulate the body content before any message processing takes place.

The program listing above shows ways of setting variable values inside a message template. First you can simply place a variable expressions inside the message (see how ${messageId} is used in the sample). In addition to that you can also use path expressions to explicitly overwrite message elements before message processing takes place.

The sample above uses an XPath expression that evaluates and searches for the right element in the message body in order to set the given value. The previously defined variable ${date} replaces the respective element value. Of course this works with XML attributes too (e.g. path expression /TestMessage/Person/@age).

Both ways via XPath or JsonPath or inline variable expressions are equal to each other. With respect to the complexity of XML namespaces and XPath you may find the inline variable expression more comfortable to use. Anyway feel free to choose the way that fits best for you.

This is how you can overwrite values in message templates in order to increase maintainability and robustness of your test.

The next usage scenario for JsonPath expressions in Citrus is the ignoring of elements during message validation. As you already know Citrus provides powerful validation mechanisms for XML and Json message format. The framework is able to compare received and expected message contents with powerful validator implementations. You can use a JsonPath expression for ignoring a very specific entry in the Json object structure.

This time we add JsonPath expressions as ignore statements. This means that we explicitly leave out the evaluated elements from validation. Obviously this mechanism is a good thing to do when dynamic message data simply is not deterministic such as timestamps and dynamic identifiers. In the example above we explicitly skip the token entry and all lastLogin values that are obviously timestamp values in milliseconds.

The JsonPath evaluation is very powerful when it comes to select a set of Json objects and elements. This is how we can ignore several elements with one single JsonPath expression which is very powerful.

Let’s continue to use JsonPath expressions when validating a received message in Citrus:

The above JsonPath expressions will be evaluated when Citrus validates the received message. The expression result is compared to the expected value where expectations can be static values as well as test variables and validation matcher expressions. In case a JsonPath expression should not be able to find any elements the test case will also fail.

Json is a pretty simple yet powerful message format. Simply put, a Json message just knows JsonObject, JsonArray and JsonValue items. The handling of JsonObject and JsonValue items in JsonPath expressions is straight forward. We just use a dot notated syntax for walking through the JsonObject hierarchy. The handling of JsonArray items is also not very difficult either. Citrus will try the best to convert JsonArray items to String representation values for comparison.

Now lets get a bit more complex with validation matchers and Json object functions. Citrus tries to give you the most comfortable validation capabilities when comparing Json object values and Json arrays. One first thing you can use is object functions like keySet() or size() . This functionality is not covered by JsonPath out of the box but added by Citrus. See the following example on how to use it:

The object functions do return special Json object related properties such as the set of keys for an object or the size of an Json array.

Now lets get even more comfortable validation capabilities with matchers. Citrus supports Hamcrest matchers which gives us a very powerful way of validating Json object elements and arrays. See the following examples that demonstrate how this works:

When using the XML DSL we have to use the assertThat validation matcher syntax for defining the Hamcrest matchers. You can combine matcher implementation as seen in the allOf(greaterThan(0), lessThan(5)) expression. When using the Java DSL you can just add the matcher as expected result object. Citrus evaluates the matchers and makes sure everything is as expected. This is a very powerful validation mechanism as it combines the Hamcrest matcher capabilities with Json message validation.

The Json schema validation in Citrus is based on the drafts provided by json-schema.org. Because Json schema is a fast evolving project, only Json schema V3 and V4 are currently supported.

Json schema validation in Citrus is optional and disabled by default. This is why the action required to explicitly enable the schema validation with schemaValidation(true). The schema references a bean in the Citrus context (e.g. a Spring bean in the application context). Read more about how to declare schemas in schema validation.

We encourage you to add Json schema validation to your test cases as soon as possible, because we think that message validation is a important part of integration testing.

Because Citrus supports different types of schema repositories, it is necessary to declare a Json schema repository as type="json". This allows Citrus to collect all Json schema files for the message validation.

The referenced schema is another bean in the configuration that represents the schema definition.

In reference to the current Json schema definition, it is not possible to create a direct reference between a Json message and a set of schemas, as it would be possible with XML namespaces. Because of that, Citrus follows a rule set for choosing the relevant schemas based on the configuration withing the test case in relation to the given context. The following table assumes that the Json schema validation is activated for the test action.

Citrus is able to verify XML message content on a received message. You as a tester can compare the whole XML message body to a predefined control message template. The Citrus message validator will walk through the XML document and compare the elements, attributes and values.

You can define the expected XML message template in multiple ways:

In Java tests that use the Citrus domain specific language you must use verbose String concatenation when constructing XML message contents inline. You need to escape reserved characters like quotes and line breaks. This is why you should consider to using external file resources in Java when dealing with large complex message data.

Inline message body definition or external file resource give us a control message template that the test case expects to validate. Citrus uses this control template for extended message comparison. All elements, namespaces, attributes and node values are validated in this comparison. When using XML message bodies Citrus will navigate through the whole XML structure validating each element and its content.

Only in case received message and control message are equal to each other as expected the message validation will pass. In case differences occur the test case fails with detailed error message.

Citrus supports various ways to add dynamic message content in the message template. Secondly, Citrus can ignore some elements that should not be part of message comparison (e.g. when generated content or timestamps are part of the message content). The tester can enrich the expected message template with test variables or ignore-expressions so we get a more robust validation mechanism. We will talk about this in the next sections to come.

A message can have multiple headers in addition to the body content. You can validate headers with expected name and the control value. Just add the following header validation to your receiving action.

Message headers are represented as name-value pairs. Each expected header element identified by its name has to be present in the received message. In addition to that the header value is compared to the given control value. If a header entry is not available, or the value does not match the expectations the test raises validation errors.

Sometimes message headers may not apply to the name-value pair pattern. For example SOAP headers can also contain XML fragments as header values. You can add complex header data as expected value in the validation.

The header data has not name but uses a complex XML fragment as a value. In SOAP this header fragment will be added as a SOAP-ENV:Header then. Please read more about this in SOAP support.

Some elements in the message payload might not apply for validation at all. Just think of communication timestamps or dynamic values that have been generated from a foreign service.

You as a tester may not be able to predict such a timestamp or dynamically value for expected validation. This is why you can safely ignore elements and attributes in the XML message validation.

The receive action above is not able to verify the elements Timestamp and MessageId. This is because the timestamp uses milliseconds and the message id has been generated by the server application. Both values must be excluded from XML validation.

You can use ignore XPath expressions that match elements in the message content that should be excluded. XPath expressions can be cumbersome and error prone though.

You can also use inline @ignore@ expressions as expected template values in order to exclude elements from valdidation. This is for those of you that do not like to write XPath expressions. As a result the ignored message elements are automatically skipped when Citrus compares and validates message contents and do not break the test case.

Feel free to mix both mechanisms to ignore message elements. Ignore expressions are valid as elements, sub-tree nodes and attributes. You can use the @ignore@ placeholder in external file resources, too.

The section XML payload validation showed how to validate the complete XML message structure with control message template. All elements are validated and compared one after another.

In some cases this approach might be too extensive. Imagine the tester only needs to validate a small subset of message elements. You would rather want to use explicit element validation with XPath.

In Java the use of a map may be the easiest way to declare multiple expressions for XPath validation.

Instead of comparing the whole message some message elements are validated explicitly via XPath. Citrus evaluates the XPath expression on the received message and compares the result value to the control value. The basic message structure as well as all other message elements are not included into this explicit validation.

TestRequest.VersionId

The expression will search the XML tree for the respective <TestRequest><VersionId> element. Attributes are supported too. In case the last element in the dot-notated expression is a XML attribute the framework will automatically find it.

Of course this dot-notated syntax is very simple and might not be applicable for more complex tree navigation. XPath is much more powerful - no doubt. The dot-notated syntax might help those of you that are not familiar with XPath. So the dot-notation is supported wherever XPath expressions might apply.

The Xpath expressions can evaluate to different result types. By default, Citrus is operating on NODE and STRING result types so that you can validate some element value. But you can also use different result types such as NODESET and BOOLEAN .

In the example above we use different expression result types. First we want to make sure nor /TestRequest/Error element is present. This can be done with a boolean result type and false value. Second we want to validate the number of found elements for the expression /TestRequest/Status[.='success'] . The XPath expression evaluates to a node list that results in its list size to be checked. And last not least we evaluate to a node-set result type where all values in the node list will be translated to a comma delimited string value.

You can use even more powerful validation expressions with matcher implementations. With validation matchers you are able to use validations such as greaterThan, lessThan, hasSize and much more.

When using the XML DSL we have to use the assertThat validation matcher syntax for defining the Hamcrest matcher. You can combine matcher implementation as seen in the anyOf(empty(), nullValue()) expression. When using the Java DSL you can just add the matcher as expected result object. Citrus evaluates the matchers and makes sure everything is as expected. This is a very powerful validation mechanism as it also works with node-sets containing multiple values as list.

This is how you can add very powerful message element validation in XML using XPath expressions.

Namespaces represent an essential concept in XML. A namespace declares an element to be part of a very specific ruleset. You have to specify namespaces also when using XPath expressions. Let’s have a look at an example message that uses XML namespaces:

Now we would like to validate some elements in this message using XPath

The validation will fail although the XPath expression looks correct regarding the XML tree. This is because the message uses the namespace xmlns:ns1="http://citrus.com/namespace". The XPath expression is not able to find the elements because of the missing namespace declaration in the expression. The correct XPath expression uses the namespace prefix as defined in the message.

Now the expressions works fine, and the validation is successful. Relying on the namespace prefix ns1 is quite error prone though. This is because the test depends on the very specific namespace prefix. As soon as the message is sent with a different namespace prefix (e.g. ns2) the validation will fail again.

You can avoid this effect when specifying your own namespace context and your own namespace prefix during validation.

Now the test is independent of any namespace prefix in the received message. The namespace context will resolve the namespaces and find the elements although the message might use different prefixes. The only thing that matters is that the namespace value (http://citrus.com/namespace) matches.

Once defined the def namespace prefix is valid in all test cases and all XPath expressions. This enables you to free your test cases from namespace prefix bindings that might be broken with time. You can use these global namespace mappings wherever XPath expressions are valid inside a test case (validation, ignore, extract).

In the previous section we have seen that XML namespaces can get tricky with XPath validation. Default namespaces can do even more! So lets look at the example with default namespaces:

The message uses default namespaces. The following approach in XPath will fail due to namespace problems.

Even default namespaces need to be specified in the XPath expressions. Look at the following code listing that works fine with default namespaces:

When working with XML data format parsing and serializing is a common task. XML structures are parsed to a DOM (Document Object Model) representation in order to process elements, attributes and text nodes. DOM node objects get serialized to a String message payload representation. The XML parser and serializer is customizable to a certain level. By default, Citrus uses the DOM Level 3 Load and Save implementation with following settings:

The parameters are also described in W3C DOM configuration documentation. We can customize the default settings by adding a XmlConfigurer Spring bean to the Citrus application context.

With the Groovy XmlSlurper you can easily validate XML message payloads without having to deal directly with XML. People who do not want to deal with XPath may also like this validation alternative.

The tester directly navigates through the message elements and uses simple code assertions in order to control the message content. Here is an example how to validate messages with Groovy script:

The Groovy XmlSlurper validation script goes right into the message-tag instead of a XML control template or XPath validation. The Groovy script supports Java assert statements for message element validation. Citrus automatically injects the root element root to the validation script. This is the Groovy XmlSlurper object and the start of element navigation. Based on this root element you can access child elements and attributes with a dot notated syntax. Just use the element names separated by a simple dot. Very easy! If you need the list of child elements use the children() function on any element. With the text() function you get access to the element’s text-value. The size() is very useful for validating the number of child elements which completes the basic validation statements.

As you can see from the example, we may use test variables within the validation script, too. Citrus has also injected the actual test context to the validation script. The test context object holds all test variables. So you can also access variables with context.getVariable("user") for instance. On the test context you can also set new variable values with context.setVariable("user", "newUserName") .

There is even more object injection for the validation script. With the automatically added object receivedMessage You have access to the Citrus message object for this receive action. This enables you to do whatever you want with the message payload or header.

The listing above shows some power of the validation script. We can access the message payload, we can access the message header. With test context access we can also save the whole message payload as a new test variable for later usage in the test.

In general Groovy code inside the XML test case definition or as part of the Java DSL code is not very comfortable to maintain. You do not have code syntax assist or code completion. This is why we can also use external file resources for the validation scripts. The syntax looks like follows:

We referenced some external file resource validationScript.groovy . This file content is loaded at runtime and is used as script body. Now that we have a normal groovy file we can use the code completion and syntax highlighting of our favorite Groovy editor.

There are several possibilities to describe the structure of XML documents. The two most popular ways are DTD (Document type definition) and XSD (XML Schema definition). In case the XML document is classified using a schema definition the structure of the document has to fit the predefined rules inside the schema definition. XML document instances are valid only in case they meet all these structure rules defined in the schema definition. Citrus can validate XML documents using the schema languages DTD and XSD.