<!-- NOTE: Use stub versions of the core plugins referenced by the build -->
  <build>
    <pluginManagement>
      <plugins>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>0.1-stub-SNAPSHOT</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>0.1-stub-SNAPSHOT</version>
        </plugin>

        assertNull(beerPhase);
    }

    @Test
    void testFindLastInPhaseMisc() throws Exception {
        MavenExecutionPlan plan = LifecycleExecutionPlanCalculatorStub.getProjectAExecutionPlan();

        assertNull(plan.findLastInPhase("pacXkage"));
        // Beer comes straight after package in stub, much like real life.

          <artifactId>maven-compiler-plugin</artifactId>
          <version>0.1-stub-SNAPSHOT</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>0.1-stub-SNAPSHOT</version>
        </plugin>
        <plugin>
          <artifactId>maven-javadoc-plugin</artifactId>
          <version>0.1-stub-SNAPSHOT</version>
        </plugin>
        <plugin>

 */
package org.apache.maven.lifecycle.internal;

import java.util.List;

import org.apache.maven.execution.MavenSession;
import org.apache.maven.lifecycle.internal.stub.LifecycleTaskSegmentCalculatorStub;
import org.apache.maven.lifecycle.internal.stub.ProjectDependencyGraphStub;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;

and can be asserted as desired.

You can change/extend these stubs, and tests should not be breaking too much, since most tests
assert using expected values from the stubs. Normally, when you try to use data from the stubs that
have not been properly populated, you'll get a nullpointer in your test and you then have to
identify which stub creates that specific piece of data.

The most important stubs are:
LifecycleExecutionPlanCalculatorStub

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.lifecycle.internal.stub;

import org.apache.maven.execution.ExecutionEvent.Type;
import org.apache.maven.execution.MavenSession;
import org.apache.maven.lifecycle.internal.ExecutionEventCatapult;
import org.apache.maven.plugin.MojoExecution;

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.lifecycle.internal.stub;

import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Set;

import org.apache.maven.lifecycle.LifeCyclePluginAnalyzer;
import org.apache.maven.model.Plugin;

            ArtifactRepository repository, File source, String remotePath, ArtifactTransferListener transferListener)
            throws ArtifactTransferFailedException {
        // TODO Auto-generated method stub

    }

    public ArtifactResolutionResult resolve(ArtifactResolutionRequest request) {
        ArtifactResolutionResult result = new ArtifactResolutionResult();

        if (request.isResolveRoot()) {

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.lifecycle.internal.stub;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.apache.maven.execution.MavenSession;

        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-resources-plugin</artifactId>
        <version>0.1-stub-SNAPSHOT</version>
      </plugin>
    </plugins>
  </build>