CreatingCustomAgents.md

Creating Testrecorder Custom Agents

The simplest way of getting a configuration to work with testrecorder is placing it on the class path (configuration files in the agentconfig directory). This concept may become inefficient applied to larger applications using custom components and changing configurations. We should advance to manage our configurations in a separate project to be able to apply different configurations to our application.

Furthermore using the original testrecorder agent has a drawback: all testrecorder dependencies (e.g. asm, byte-buddy, objenenis) are placed on the classpath, possibly leading to version conflicts if the application uses the same dependencies in other versions.

For this reason we recommend to build a custom agent for larger projects:

• containing all configuration files in agentconfig
• containing all custom components on the classpath
• relocating all colliding dependencies to prevent version conflicts

First create a new maven project. The pom.xml should contain

• all dependencies you need for your custom components. Try to depend on a minimal set of dependencies. Each dependency shared between the agent and the system under test could lead to version conflicts or class loader problems. Consider using the provided scope in such cases.

• a dependency to the testrecorder agent

<dependency>
    <groupId>net.amygdalum</groupId>
    <artifactId>testrecorder-agent</artifactId>
    <version>0.9.0</version>
</dependency>

• a section for the maven-shade-plugin configured similar to:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>3.2.1</version>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
                <shadedArtifactAttached>true</shadedArtifactAttached>
                <shadedClassifierName>agent</shadedClassifierName>
                <keepDependenciesWithProvidedScope>false</keepDependenciesWithProvidedScope>
                <relocations>
                    <relocation>
                        <pattern>org.objectweb.asm</pattern>
                        <shadedPattern>net.amygdalum.shaded.objectweb.asm</shadedPattern>
                    </relocation>
                    <relocation>
                        <pattern>org.objenesis</pattern>
                        <shadedPattern>net.amygdalum.shaded.objenesis</shadedPattern>
                    </relocation>
                    <relocation>
                        <pattern>net.bytebuddy</pattern>
                        <shadedPattern>net.amygdalum.shaded.bytebuddy</shadedPattern>
                    </relocation>
                    <relocation>
                        <pattern>org.antlr</pattern>
                        <shadedPattern>net.amygdalum.shaded.antlr</shadedPattern>
                    </relocation>
                    <relocation>
                        <pattern>org.stringtemplate</pattern>
                        <shadedPattern>net.amygdalum.shaded.stringtemplate</shadedPattern>
                    </relocation>
                </relocations>
                <transformers>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                        <manifestEntries>
                            <Premain-Class>net.amygdalum.testrecorder.TestRecorderAgent</Premain-Class>
                            <Agent-Class>net.amygdalum.testrecorder.TestRecorderAgent</Agent-Class>
                            <Can-Redefine-Classes>true</Can-Redefine-Classes>
                            <Can-Retransform-Classes>true</Can-Retransform-Classes>
                        </manifestEntries>
                    </transformer>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                        <resource>agentconfig/net.amygdalum.testrecorder.deserializers.builder.SetupGenerator</resource>
                    </transformer>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                        <resource>agentconfig/net.amygdalum.testrecorder.deserializers.matcher.MatcherGenerator</resource>
                    </transformer>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                        <resource>agentconfig/net.amygdalum.testrecorder.profile.PerformanceProfile</resource>
                    </transformer>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                        <resource>agentconfig/net.amygdalum.testrecorder.profile.SerializationProfile</resource>
                    </transformer>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                        <resource>agentconfig/net.amygdalum.testrecorder.types.Serializer</resource>
                    </transformer>
                </transformers>
            </configuration>
        </execution>
    </executions>
</plugin>