Maven plugin to verify a provider
Maven plugin for verifying pacts against a provider.
NOTE: If you are running your tests with the JUnit runners, you do not need this plugin.
The Maven plugin provides a verify
goal which will verify all configured pacts against your provider.
To Use It
build
section of your pom file.
1. Add the pact-jvm-provider-maven plugin to your 2. Define the pacts between your consumers and providers
You define all the providers and consumers within the configuration element of the maven plugin.
mvn pact:verify
3. Execute You will have to have your provider running for this to pass.
Verifying all pact files in a directory for a provider
You can specify a directory that contains pact files, and the Pact plugin will scan for all pact files that match that provider and define a consumer for each pact file in the directory. Consumer name is read from contents of pact file.
Verifying all pact files from multiple directories for a provider
If you want to specify multiple directories, you can use pactFileDirectories
. The plugin will only fail the build if
no pact files are loaded after processing all the directories in the list.
Enabling insecure SSL
For providers that are running on SSL with self-signed certificates, you need to enable insecure SSL mode by setting
<insecure>true</insecure>
on the provider.
Specifying a custom trust store
For environments that are running their own certificate chains:
trustStore
is either relative to the current working (build) directory. trustStorePassword
defaults to changeit
.
NOTE: The hostname will still be verified against the certificate.
Modifying the requests before they are sent
Sometimes you may need to add things to the requests that can't be persisted in a pact file. Examples of these would
be authentication tokens, which have a small life span. The Pact Maven plugin provides a request filter that can be
set to a Groovy script on the provider that will be called before the request is made. This script will receive the HttpRequest
bound to a variable named request
prior to it being executed.
Important Note: You should only use this feature for things that can not be persisted in the pact file. By modifying the request, you are potentially modifying the contract from the consumer tests!
Modifying the HTTP Client Used
The default HTTP client is used for all requests to providers (created with a call to HttpClients.createDefault()
).
This can be changed by specifying a closure assigned to createClient on the provider that returns a CloseableHttpClient.
For example:
Turning off URL decoding of the paths in the pact file
By default the paths loaded from the pact file will be decoded before the request is sent to the provider. To turn this
behaviour off, set the system property pact.verifier.disableUrlPathDecoding
to true
.
Important Note: If you turn off the url path decoding, you need to ensure that the paths in the pact files are correctly encoded. The verifier will not be able to make a request with an invalid encoded path.
Plugin Properties
The following plugin properties can be specified with -Dproperty=value
on the command line or in the configuration section:
Property | Description |
---|---|
pact.showStacktrace | This turns on stacktrace printing for each request. It can help with diagnosing network errors |
pact.showFullDiff | This turns on displaying the full diff of the expected versus actual bodies |
pact.filter.consumers | Comma separated list of consumer names to verify |
pact.filter.description | Only verify interactions whose description match the provided regular expression |
pact.filter.providerState | Only verify interactions whose provider state match the provided regular expression. An empty string matches interactions that have no state |
pact.filter.pacturl | This filter allows just the just the changed pact specified in a webhook to be run. It should be used in conjunction with pact.filter.consumers |
pact.verifier.publishResults | Publishing of verification results will be skipped unless this property is set to true [version 3.5.18+] |
pact.matching.wildcard | Enables matching of map values ignoring the keys when this property is set to true |
pact.verifier.disableUrlPathDecoding | Disables decoding of request paths |
pact.pactbroker.httpclient.usePreemptiveAuthentication | Enables preemptive authentication with the pact broker when set to true |
pact.consumer.tags | Overrides the tags used when publishing pacts [version 4.0.7+] |
pact.content_type.override.<TYPE>.<SUBTYPE>=text\|binary | Overrides the handling of a particular content type [version 4.1.3+] |
Example in the configuration section:
Provider States
For each provider you can specify a state change URL to use to switch the state of the provider. This URL will receive the providerState description and parameters from the pact file before each interaction via a POST. The stateChangeUsesBody controls if the state is passed in the request body or as query parameters.
These values can be set at the provider level, or for a specific consumer. Consumer values take precedent if both are given.
If the stateChangeUsesBody
is not specified, or is set to true, then the provider state description and parameters will be sent as
JSON in the body of the request. If it is set to false, they will passed as query parameters.
As for normal requests (see Modifying the requests before they are sent), a state change request can be modified before
it is sent. Set stateChangeRequestFilter
to a Groovy script on the provider that will be called before the request is made.
Teardown calls for state changes
You can enable teardown state change calls by setting the property <stateChangeTeardown>true</stateChangeTeardown>
on the provider. This
will add an action
parameter to the state change call. The setup call before the test will receive action=setup
, and
then a teardown call will be made afterwards to the state change URL with action=teardown
.
Returning values that can be injected
You can have values from the provider state callbacks be injected into most places (paths, query parameters, headers, bodies, etc.). This works by using the V3 spec generators with provider state callbacks that return values. One example of where this would be useful is API calls that require an ID which would be auto-generated by the database on the provider side, so there is no way to know what the ID would be beforehand.
There are methods on the consumer DSLs that can provider an expression that contains variables (like '/api/user/${id}'
for the path). The provider state callback can then return a map for values, and the id
attribute from the map will
be expanded in the expression. For URL callbacks, the values need to be returned as JSON in the response body.
Verifying pact files from a pact broker
You can setup your build to validate against the pacts stored in a pact broker. The pact plugin will query
the pact broker for all consumers that have a pact with the provider based on its name. To use it, just configure the
pactBrokerUrl
or pactBroker
value for the provider with the base URL to the pact broker.
For example:
Verifying pacts from an authenticated pact broker
If your pact broker requires authentication (basic and bearer authentication are supported), you can configure the username
and password to use by configuring the authentication
element of the pactBroker
element of your provider.
For example, here is how you configure the plugin to use basic authentication for verifying pacts:
Here is how you configure the plugin to use bearer token authentication for verifying pacts
Preemptive Authentication can be enabled by setting the pact.pactbroker.httpclient.usePreemptiveAuthentication
Java
system property to true
.
Allowing just the changed pact specified in a webhook to be verified [4.0.6+]
When a consumer publishes a new version of a pact file, the Pact broker can fire off a webhook with the URL of the changed
pact file. To allow only the changed pact file to be verified, you can override the URL by using the pact.filter.consumers
and pact.filter.pacturl
Java system properties.
For example, running:
will only run the verification for Foo Web Client with the given pact file URL.
Using the Maven servers configuration
You can use the servers setup in the Maven settings. To do this, setup a server as per the Maven Server Settings. Then set the server ID in the pact broker configuration in your POM.
Verifying pacts from a pact broker that match particular tags
If your pacts in your pact broker have been tagged, you can set the tags to fetch by configuring the tags
element of the pactBroker
element of your provider.
For example:
This example will fetch and validate the pacts for the TEST and DEV tags.
Filtering the interactions that are verified
You can filter the interactions that are run using three properties: pact.filter.consumers
, pact.filter.description
and pact.filter.providerState
.
Adding -Dpact.filter.consumers=consumer1,consumer2
to the command line or configuration section will only run the pact files for those
consumers (consumer1 and consumer2). Adding -Dpact.filter.description=a request for payment.*
will only run those interactions
whose descriptions start with 'a request for payment'. -Dpact.filter.providerState=.*payment
will match any interaction that
has a provider state that ends with payment, and -Dpact.filter.providerState=
will match any interaction that does not have a
provider state.
Not failing the build if no pact files are found
By default, if there are no pact files to verify, the plugin will raise an exception. This is to guard against false positives where the build is passing but nothing has been verified due to mis-configuration.
To disable this behaviour, set the failIfNoPactsFound
parameter to false
.
Verifying a message provider
The Maven plugin has been updated to allow invoking test methods that can return the message contents from a message
producer. To use it, set the way to invoke the verification to ANNOTATED_METHOD
. This will allow the pact verification
task to scan for test methods that return the message contents.
Add something like the following to your maven pom file:
Now when the pact verify task is run, will look for methods annotated with @PactVerifyProvider
in the test classpath
that have a matching description to what is in the pact file.
It will then validate that the returned contents matches the contents for the message in the pact file.
Changing the class path that is scanned
By default, the test classpath is scanned for annotated methods. You can override this by setting
the classpathElements
property:
Publishing pact files to a pact broker
NOTE: There is a pact CLI that can be used to publish pacts. See https://github.com/pact-foundation/pact-ruby-cli.
The pact maven plugin provides a publish
mojo that can publish all pact files in a directory
to a pact broker. To use it, you need to add a publish configuration to the POM that defines the
directory where the pact files are and the URL to the pact broker.
For example:
You can now execute mvn pact:publish
to publish the pact files.
NOTE: The pact broker requires a version for all published pacts. The publish
task will use the version of the
project by default, but can be overwritten with the projectVersion
property. Make sure you have set one otherwise the broker will reject the pact files.
NOTE: By default, the pact broker has issues parsing SNAPSHOT
versions. You can configure the publisher to
automatically remove -SNAPSHOT
from your version number by setting trimSnapshot
to true. This setting does not modify non-snapshot versions.
You can set any tags that the pacts should be published with by setting the tags
list property. A common use of this
is setting the tag to the current source control branch. This supports using pact with feature branches.
You can also specify the tags using the pact.consumer.tags
Java system property [version 4.0.7+].
Publishing to an authenticated pact broker
For an authenticated pact broker, you can pass in the credentials with the pactBrokerUsername
and pactBrokerPassword
properties. Currently, it only supports basic authentication or a bearer token.
For example:
Or to use a bearer token:
Using the Maven servers configuration
You can use the servers setup in the Maven settings. To do this, setup a server as per the Maven Server Settings. Then set the server ID in the pact broker configuration in your POM.
Excluding pacts from being published
You can exclude some of the pact files from being published by providing a list of regular expressions that match against the base names of the pact files.
For example:
Overriding the handling of a body data type
NOTE: version 4.1.3+
By default, bodies will be handled based on their content types. For binary contents, the bodies will be base64
encoded when written to the Pact file and then decoded again when the file is loaded. You can change this with
an override property: pact.content_type.override.<TYPE>.<SUBTYPE>=text|binary
. For instance, setting
pact.content_type.override.application.pdf=text
will treat PDF bodies as a text type and not encode/decode them.
Publishing verification results to a Pact Broker
For pacts that are loaded from a Pact Broker, the results of running the verification can be published back to the broker against the URL for the pact. You will be able to then see the result on the Pact Broker home screen.
To turn on the verification publishing, set the system property pact.verifier.publishResults
to true
in the pact maven plugin, not surefire, configuration.
Tagging the provider before verification results are published [4.0.1+]
You can have a tag pushed against the provider version before the verification results are published. To do this
you need set the pact.provider.tag
JVM system property to the tag value.
From 4.1.8+, you can specify multiple tags with a comma separated string for the pact.provider.tag
system property.
Enabling other verification reports
By default the verification report is written to the console. You can also enable a JSON or Markdown report by setting
the reports
configuration list.
These reports will be written to target/reports/pact
.
Pending Pact Support (version 4.1.0 and later)
If your Pact broker supports pending pacts, you can enable support for that by enabling that on your Pact broker annotation or with JVM system properties. You also need to provide the tags that will be published with your provider's verification results. The broker will then label any pacts found that don't have a successful verification result as pending. That way, if they fail verification, the verifier will ignore those failures and not fail the build.
For example:
Then any pending pacts will not cause a build failure.