Make dep on matrix-project optional

pom.xml

@@ -75,6 +75,12 @@
         <artifactId>jenkins-test-harness-tools</artifactId>
         <version>2.2</version>
         <scope>test</scope>
+         <exclusions>
+            <exclusion>
+               <groupId>org.jenkins-ci.plugins</groupId>
+               <artifactId>gradle</artifactId>
+            </exclusion>
+         </exclusions>
       </dependency>
       <dependency>
         <groupId>org.jenkins-ci.plugins</groupId>
@@ -84,6 +90,7 @@
       <dependency>
         <groupId>org.jenkins-ci.plugins</groupId>
         <artifactId>matrix-project</artifactId>
+        <optional>true</optional>
       </dependency>
       <dependency>
         <groupId>org.jenkins-ci.plugins.workflow</groupId>

src/main/java/hudson/plugins/copyartifact/CopyArtifact.java

@@ -286,10 +286,14 @@
 
     // get all CopyArtifacts configured to AbstractProject. This works both for Project and MatrixProject.
     private static List<CopyArtifact> getCopyArtifactsInProject(AbstractProject<?,?> project) {
-        DescribableList<Builder,Descriptor<Builder>> list =
-                project instanceof Project ? ((Project<?,?>)project).getBuildersList()
-                  : (project instanceof MatrixProject ?
-                      ((MatrixProject)project).getBuildersList() : null);
+        DescribableList<Builder,Descriptor<Builder>> list;
+        if (project instanceof Project) {
+            list = ((Project<?,?>)project).getBuildersList();
+        } else if (Jenkins.get().getPlugin("matrix-project") != null && project instanceof MatrixProject) {
+            list = ((MatrixProject)project).getBuildersList();
+        } else {
+            list = null;
+        }
         if (list == null) {
             return Collections.emptyList();
         }
@@ -543,7 +547,7 @@
             if (!ok) {
                 throw new AbortException(Messages.CopyArtifact_FailedToCopy(expandedProject, expandedFilter));
             }
-        } else if (src instanceof MatrixBuild) {
+        } else if (jenkins.getPlugin("matrix-project") != null && src instanceof MatrixBuild) {
             boolean ok = false;
             // Copy artifacts from all configurations of this matrix build
             // Use MatrixBuild.getExactRuns if available
@@ -854,10 +858,10 @@
             if (item != null) {
                 if (jenkins.getPlugin("maven-plugin") != null && item instanceof MavenModuleSet) {
                     result = FormValidation.warning(Messages.CopyArtifact_MavenProject());
+                } else if (jenkins.getPlugin("matrix-project") != null && item instanceof MatrixProject) {
+                    result = FormValidation.warning(Messages.CopyArtifact_MatrixProject());
                 } else {
-                    result = (item instanceof MatrixProject)
-                          ? FormValidation.warning(Messages.CopyArtifact_MatrixProject())
-                          : FormValidation.ok();
+                    result = FormValidation.ok();
                 }
             } else if (value.indexOf('$') >= 0) {
                 result = FormValidation.warning(Messages.CopyArtifact_ParameterizedName());

src/test/java/hudson/plugins/copyartifact/OptionalDepsTest.java

@@ -0,0 +1,58 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2024 CloudBees, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package hudson.plugins.copyartifact;
+
+import org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition;
+import org.jenkinsci.plugins.workflow.job.WorkflowJob;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.hudson.test.RealJenkinsRule;
+import org.jvnet.hudson.test.TailLog;
+
+/** Verifies that basic functionality works without optional plugin dependencies. */
+public final class OptionalDepsTest {
+
+    @Rule public RealJenkinsRule r = new RealJenkinsRule().omitPlugins("maven-plugin", "matrix-project");
+
+    @Test public void usePipeline() throws Throwable {
+        r.then(OptionalDepsTest::_usePipeline);
+    }
+
+    /** Adapted from {@link CopyArtifactWorkflowTest#testLastCompletedBuildSelector}. */
+    private static void _usePipeline(JenkinsRule r) throws Throwable {
+        var upstream = r.createProject(WorkflowJob.class, "upstream");
+        upstream.setDefinition(new CpsFlowDefinition("node {writeFile text: 'upstream content', file: 'x.txt'; archiveArtifacts 'x.txt'}", true));
+        try (var tail = new TailLog(r, "upstream", 1)) {
+            r.buildAndAssertSuccess(upstream);
+        }
+        var downstream = r.createProject(WorkflowJob.class, "downstream");
+        downstream.setDefinition(new CpsFlowDefinition("node {copyArtifacts(projectName: 'upstream', selector: lastCompleted()); echo readFile('x.txt')}", true));
+        try (var tail = new TailLog(r, "downstream", 1)) {
+            r.assertLogContains("upstream content", r.buildAndAssertSuccess(downstream));
+        }
+    }
+
+}