Test generation in "spring-cloud-contract-maven-plugin" fails when there are multiple <execution> sections with goal "generateTests".

[valerii-yakubovych]

Context:

• There is dedicated repository with multiple consumer contracts that are released as different Maven artifacts, i.e. 'some-stubs-1', 'some-stubs-2', and so on.
• There is a service with two producers, producer-1 and producer-2.
• Producer-1 should be tested against 'some-stubs-1' contract.
• Producer-2 should be tested against 'some-stubs-2' contract.
• There is spring-cloud-contract-maven-plugin:3.1.3 plugin with two <execution> sections. Section with id execution-1 is supposed to execute tests against producer-1. Section with id execution-2 is supposed to execute tests against producer-2. Two <execution> sections are necessary because it is not possible to put more then one <contractDependency> in one <configuration>.

<plugin>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-contract-maven-plugin</artifactId>
    <version>3.1.3</version>
    <executions>
        <execution>
            <id>execution-1</id>
            <goals>
                <goal>generateTests</goal>
            <goals>
            <configuration>
                <contractDependency>
                    <groupId>com.experiment</groupId>
                    <artifactId>some-stubs-1</artifactId>
                    <version>1.0.0</version>
                    <classifier>stubs</classifier>
                <contractDependency>
                <packageWithBaseClasses>package.base.stubs1</packageWithBaseClasses>
            <configuration>
        </execution>
        <execution>
            <id>execution-2</id>
            <goals>
                <goal>generateTests</goal>
            <goals>
            <configuration>
                <contractDependency>
                    <groupId>com.experiment</groupId>
                    <artifactId>some-stubs-2</artifactId>
                    <version>1.0.0</version>
                    <classifier>stubs</classifier>
                <contractDependency>
                <packageWithBaseClasses>package.base.stubs2</packageWithBaseClasses>
            <configuration>
        </execution>
    <executions>
    <configuration>
        <nameSuffixForTests>CdcTest</nameSuffixForTests>
        <contractsPath>/</contractsPath>
        <contractsMode>LOCAL</contractsMode>
    <configuration>
<plugin>

some-stubs-1 contract:

package com.example

import org.springframework.cloud.contract.spec.Contract

Contract.make {
  label("coolTest")
  input {
    triggeredBy("coolTest()")
  }
  outputMessage {
    sentTo("cool.kafka.topic")
    body'''
      {
        "cool": 1234
      }
    '''
  }
}

some-stubs-2 contract:

package com.example

import org.springframework.cloud.contract.spec.Contract

Contract.make {
  label("nastyTest")
  input {
    triggeredBy("nastyTest()")
  }
  outputMessage {
    sentTo("nasty.kafka.topic")
    body'''
      {
        "nasty": 1234
      }
    '''
  }
}

mvn clean install

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.7.0:testCompile (default-testCompile) on project cool-project: Compilation failure
[ERROR] .../target/generated-test-sources/contracts/.../some-stubs-1/CoolCdcTest.java:[20,8] duplicate class: com.example.cdc.META_INF.com.example.some-stubs-2...CoolCdcTest

What actually happens:
Plugin generates two test classes with the same name in different packages:

com.example.META_INF...some-stubs-1...CoolCdcTest
com.example.META_INF...some-stubs-2...CoolCdcTest

Why it happens:
Two artifacts some-stubs-1 and some-stubs-2 should be download. But MavenContractsDownloader class after downloading the first some-stubs-1 artifact caches it.
And before downloading the second artifact some-stubs-2, MavenContractsDownloader checks the cache and returns first cached artifact some-stubs-1 as the second some-stubs-2.
I.e. caching does not check is it correct artifact cached or not. It just check that something is cached and returns it.

It seems there may be two solutions:

• cache artifact's groupId:artifactId:version and check against it
• make cache deactivatable with some property

[valerii-yakubovych]

Thanks 😃

[marcingrzejszczak]

Thanks for doing a very good analysis - it was super easy to fix it then.