Adding Source path for test-compile

[Paige, Gary]

Currently I have a step that generates new sources during the
generate-test-sources
I need to add that directory to the source path during test-compile - 
I have tried several ways :

<plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-compiler-plugin</artifactId>
                         <configuration>
                            <testIncludes>
                                    <include
implementation="java.lang.String">target/test-generated</include>
                                </testIncludes>
                                <source>1.5</source>
                                <target>1.5</target>
                        </configuration>
                 </plugin>

The above is my last attempt - I have also tried adding execution blocks


Any help would be appreciated.