[[test-component]]
== Test Component

*Available as of Camel version 1.3*

Testing of distributed and asynchronous processing is
notoriously difficult. The <<mock-component,Mock>>, <<mock-component,Test>>
and <<dataset-component,DataSet>> endpoints work great with the
Camel Testing Framework to simplify your unit and
integration testing using
link:enterprise-integration-patterns.html[Enterprise Integration
Patterns] and Camel's large range of Components
together with the powerful Bean Integration.

The *test* component extends the <<mock-component,Mock>> component to
support pulling messages from another endpoint on startup to set the
expected message bodies on the underlying <<mock-component,Mock>> endpoint.
That is, you use the test endpoint in a route and messages arriving on
it will be implicitly compared to some expected messages extracted from
some other location.

So you can use, for example, an expected set of message bodies as files.
This will then set up a properly configured <<mock-component,Mock>>
endpoint, which is only valid if the received messages match the number
of expected messages and their message payloads are equal.

Maven users will need to add the following dependency to their `pom.xml`
for this component when using *Camel 2.8* or older:

[source,xml]
----
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-spring</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>
----

From Camel 2.9 onwards the <<test-component,Test>> component is provided
directly in the camel-core.

=== URI format

[source]
----
test:expectedMessagesEndpointUri
----

Where *expectedMessagesEndpointUri* refers to some other
Component URI that the expected message bodies are
pulled from before starting the test.

=== URI Options

// component options: START
The Test component has no options.
// component options: END


// endpoint options: START
The Test endpoint is configured using URI syntax:

----
test:name
----

with the following path and query parameters:

==== Path Parameters (1 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *name* | *Required* Name of endpoint to lookup in the registry to use for polling messages used for testing |  | String
|===


==== Query Parameters (14 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *anyOrder* (producer) | Whether the expected messages should arrive in the same order or can be in any order. | false | boolean
| *assertPeriod* (producer) | Sets a grace period after which the mock endpoint will re-assert to ensure the preliminary assertion is still valid. This is used for example to assert that exactly a number of messages arrives. For example if link expectedMessageCount(int) was set to 5, then the assertion is satisfied when 5 or more message arrives. To ensure that exactly 5 messages arrives, then you would need to wait a little period to ensure no further message arrives. This is what you can use this link setAssertPeriod(long) method for. By default this period is disabled. | 0 | long
| *delimiter* (producer) | The split delimiter to use when split is enabled. By default the delimiter is new line based. The delimiter can be a regular expression. |  | String
| *expectedCount* (producer) | Specifies the expected number of message exchanges that should be received by this endpoint. Beware: If you want to expect that 0 messages, then take extra care, as 0 matches when the tests starts, so you need to set a assert period time to let the test run for a while to make sure there are still no messages arrived; for that use link setAssertPeriod(long). An alternative is to use NotifyBuilder, and use the notifier to know when Camel is done routing some messages, before you call the link assertIsSatisfied() method on the mocks. This allows you to not use a fixed assert period, to speedup testing times. If you want to assert that exactly n'th message arrives to this mock endpoint, then see also the link setAssertPeriod(long) method for further details. | -1 | int
| *reportGroup* (producer) | A number that is used to turn on throughput logging based on groups of the size. |  | int
| *resultMinimumWaitTime* (producer) | Sets the minimum expected amount of time (in millis) the link assertIsSatisfied() will wait on a latch until it is satisfied | 0 | long
| *resultWaitTime* (producer) | Sets the maximum amount of time (in millis) the link assertIsSatisfied() will wait on a latch until it is satisfied | 0 | long
| *retainFirst* (producer) | Specifies to only retain the first n'th number of received Exchanges. This is used when testing with big data, to reduce memory consumption by not storing copies of every Exchange this mock endpoint receives. Important: When using this limitation, then the link getReceivedCounter() will still return the actual number of received Exchanges. For example if we have received 5000 Exchanges, and have configured to only retain the first 10 Exchanges, then the link getReceivedCounter() will still return 5000 but there is only the first 10 Exchanges in the link getExchanges() and link getReceivedExchanges() methods. When using this method, then some of the other expectation methods is not supported, for example the link expectedBodiesReceived(Object...) sets a expectation on the first number of bodies received. You can configure both link setRetainFirst(int) and link setRetainLast(int) methods, to limit both the first and last received. | -1 | int
| *retainLast* (producer) | Specifies to only retain the last n'th number of received Exchanges. This is used when testing with big data, to reduce memory consumption by not storing copies of every Exchange this mock endpoint receives. Important: When using this limitation, then the link getReceivedCounter() will still return the actual number of received Exchanges. For example if we have received 5000 Exchanges, and have configured to only retain the last 20 Exchanges, then the link getReceivedCounter() will still return 5000 but there is only the last 20 Exchanges in the link getExchanges() and link getReceivedExchanges() methods. When using this method, then some of the other expectation methods is not supported, for example the link expectedBodiesReceived(Object...) sets a expectation on the first number of bodies received. You can configure both link setRetainFirst(int) and link setRetainLast(int) methods, to limit both the first and last received. | -1 | int
| *sleepForEmptyTest* (producer) | Allows a sleep to be specified to wait to check that this endpoint really is empty when link expectedMessageCount(int) is called with zero | 0 | long
| *split* (producer) | If enabled the the messages loaded from the test endpoint will be split using new line delimiters so each line is an expected message. For example to use a file endpoint to load a file where each line is an expected message. | false | boolean
| *timeout* (producer) | The timeout to use when polling for message bodies from the URI | 2000 | long
| *copyOnExchange* (producer) | Sets whether to make a deep copy of the incoming Exchange when received at this mock endpoint. Is by default true. | true | boolean
| *synchronous* (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean
|===
// endpoint options: END


=== Example

For example, you could write a test case as follows:

[source,java]
----
from("seda:someEndpoint").
  to("test:file://data/expectedOutput?noop=true");
----

If your test then invokes the
http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/component/mock/MockEndpoint.html#assertIsSatisfied(org.apache.camel.CamelContext)[MockEndpoint.assertIsSatisfied(camelContext)
method], your test case will perform the necessary assertions.

To see how you can set other expectations on the test endpoint, see the
<<mock-component,Mock>> component.

=== See Also

* Spring Testing
