I'm trying to generate pacts from spring cloud contracts as shown at the documentation. It works just find when the response body root is a json, however when I'm trying to generate a pact that return an array of jsons it generates an empty body. I´ve tried using groovy dsl with String format """[{}...]""" and using DslProperty [value()...]. Here are my contracts:
With string format
Contract.make {
description "should return a list of dummy object with dummy value. Generates pact with empty json"
request {
method GET()
url("/dummy")
}
response {
body("""[{"value": "Hi! I'm a dummy object ;)"}]""")
headers {
contentType applicationJson()
}
status 200
}}
With DslProperty
Contract.make {
description "should return a list of dummy object with dummy value. Generates pact with empty body list"
request {
method GET()
url("/dummy")
}
response {
body([value(value: "Hi! I'm a dummy object ;)")])
headers {
contentType applicationJson()
}
status 200
}}
And that's the file generate at target/pacts
{
"provider": {
"name": "Provider"
},
"consumer": {
"name": "Consumer"
},
"interactions": [
{
"description": "should return a list of dummy object with dummy value. Generates pact with empty body list",
"request": {
"method": "GET",
"path": "/dummy"
},
"response": {
"status": 200,
"headers": {
"Content-Type": "application/json"
},
"body": [
],
"matchingRules": {
"header": {
"Content-Type": {
"matchers": [
{
"match": "regex",
"regex": "application/json.*"
}
],
"combine": "AND"
}
}
}
}
},
{
"description": "should return a list of dummy object with dummy value. Generates pact with empty json",
"request": {
"method": "GET",
"path": "/dummy"
},
"response": {
"status": 200,
"headers": {
"Content-Type": "application/json"
},
"body": {
},
"matchingRules": {
"header": {
"Content-Type": {
"matchers": [
{
"match": "regex",
"regex": "application/json.*"
}
],
"combine": "AND"
}
}
}
}
}
],
"metadata": {
"pactSpecification": {
"version": "3.0.0"
},
"pact-jvm": {
"version": "3.5.23"
}
}}
I'm using the following versions
<spring-cloud.version>Hoxton.BUILD-SNAPSHOT</spring-cloud.version>
<spring-cloud-contract.version>2.0.1.RELEASE</spring-cloud-contract.version>
<pact-jvm-provider-maven.version>3.5.23</pact-jvm-provider-maven.version>
and that's my plugin configuration
<!-- SCC to pact see https://cloud.spring.io/spring-cloud-contract/reference/html/howto.html#how-to-generate-pact-from-scc-->
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.6.0</version>
<executions>
<execution>
<id>convert-dsl-to-pact</id>
<phase>process-test-classes</phase>
<configuration>
<classpathScope>test</classpathScope>
<mainClass>
org.springframework.cloud.contract.verifier.util.ToFileContractsTransformer
</mainClass>
<arguments>
<argument>
org.springframework.cloud.contract.verifier.spec.pact.PactContractConverter
</argument>
<argument>${project.basedir}/target/pacts</argument>
<argument>
${project.basedir}/src/test/resources/contracts
</argument>
</arguments>
</configuration>
<goals>
<goal>java</goal>
</goals>
</execution>
</executions>
</plugin>
While debugging throgh the plugin I've seen that what is happening respectively is:
- When declaring body as “”” [{...}] “”” Pact converter assumes that the body is an String instance so it goes through traverse method at org.springframework.cloud.contract.verifier.spec.pact.BodyConverter. And since it starts with [ it is not parsed.
org.springframework.cloud.contract.verifier.spec.pact.BodyConverter
private static DslPart traverse(Object value, DslPart parent, Closure dslPropertyValueExtractor) {
...
if (v instanceof String) {
v = v.trim()
if (v.startsWith("{") && v.endsWith("}")) {
try {
v = jsonSlurper.parseText(v as String)
}
catch (JsonException ex) { /*it wasn't a JSON string after all...*/
}
}
}
...
On the other hand, when going through the plugin code using the DslProperty I have an object like [DslProperty{clientValue=DslProperty}]. The first DslProperty is being extracted but since the content is another DslProperty and there’s no recursive extraction I end up with an empty body because v isn’t an instance of the Gstring, String, Number, Map, Collection. So I get an empty body again.
org.springframework.cloud.contract.verifier.spec.pact.BodyConverter
private static void processCollection(Collection values, PactDslJsonArray jsonArray, Closure dslPropertyValueExtractor) {
values.forEach({
Object v = it
if (v instanceof DslProperty) {
v = dslPropertyValueExtractor(v)
}
if (v instanceof GString) {
v = ContentUtils.extractValue(v, dslPropertyValueExtractor)
}
if (v == null) {
jsonArray.nullValue()
}
else if (v instanceof String) {
jsonArray.string(v)
}
else if (v instanceof Number) {
jsonArray.number(v)
}
else if (v instanceof Map) {
PactDslJsonBody current = jsonArray.object()
traverse(v, current, dslPropertyValueExtractor)
current.closeObject()
}
else if (v instanceof Collection) {
PactDslJsonArray current = jsonArray.array()
traverse(v, current, dslPropertyValueExtractor)
current.closeArray()
}
})
}
I've published an example at https://github.com/brjt23/contract-to-pact/tree/master in case more info about how I did build the project is required.
Is there something I'm doing wrong on defining my groovy contract files? I guess I missunderstood something about how the response body should be defined.
You need to create an array of groovy objects in your body like this:
body([
[value: "Object1"],
[value: "Object2"]
])
This way spring cloud contracts will generate the correct code needed for your contracts.