Ignore intra-project dependencies in checkUnusedDependencies (#2748)

changelog/@unreleased/pr-2748.v2.yml

@@ -0,0 +1,7 @@
+type: improvement
+improvement:
+  description: Ignore intra-project dependencies in `checkUnusedDependencies`. This
+    allows `checkUnusedDependencies` to be used with Gradle test fixtures even when
+    the test fixtures are not used by the tests.
+  links:
+  - https://github.com/palantir/gradle-baseline/pull/2748

gradle-baseline-java/src/main/groovy/com/palantir/baseline/plugins/BaselineExactDependencies.java

@@ -182,6 +182,10 @@ private static void configureSourceSet(
                             task.setSourceClasses(sourceSet.getOutput().getClassesDirs());
                             task.getDependenciesConfigurations().add(explicitCompile);
 
+                            // ignore intra-project dependencies, which are typically added automatically for things
+                            // like test fixtures
+                            task.ignore(project.getGroup().toString(), project.getName());
+
                             // this is liberally applied to ease the Java8 -> 11 transition
                             task.ignore("javax.annotation", "javax.annotation-api");
 
@@ -278,7 +282,7 @@ private static String asDependencyString(ResolvedArtifact artifact, boolean with
                     .append(projectComponentId.getProjectPath())
                     .append("')");
             if (withName) {
-                builder.append(" (").append(artifact.getId().getDisplayName()).append(")");
+                builder.append(" <-- ").append(artifact.getName());
             }
             return builder.toString();
         }

gradle-baseline-java/src/test/groovy/com/palantir/baseline/BaselineExactDependenciesTest.groovy

@@ -163,7 +163,7 @@ class BaselineExactDependenciesTest extends AbstractPluginTest {
         task << ['checkUnusedDependencies', 'checkImplicitDependencies']
     }
 
-    def 'checkUnusedDependenciesTest passes if dependency from main source set is not referenced in test'() {
+    def 'checkUnusedDependenciesTest passes if main source set is not referenced in test'() {
         when:
         buildFile << standardBuildFile
         buildFile << """
@@ -188,6 +188,20 @@ class BaselineExactDependenciesTest extends AbstractPluginTest {
         result.task(':checkUnusedDependenciesTest').getOutcome() == TaskOutcome.SUCCESS
     }
 
+    def 'checkUnusedDependenciesTest passes if test fixture source set is not referenced in test'() {
+        when:
+        buildFile << standardBuildFile
+        buildFile << """
+        plugins {
+            id 'java-test-fixtures'
+        }
+        """
+
+        then:
+        def result = with('checkUnusedDependencies', '--stacktrace').build()
+        result.task(':checkUnusedDependenciesTest').getOutcome() == TaskOutcome.SUCCESS
+    }
+
     def 'checkImplicitDependencies fails when a class is imported without being declared as a dependency'() {
         when:
         buildFile << standardBuildFile
@@ -263,7 +277,7 @@ class BaselineExactDependenciesTest extends AbstractPluginTest {
 
         then:
         BuildResult result = with(':checkUnusedDependencies', '--stacktrace').withDebug(true).buildAndFail()
-        result.output.contains "project(':sub-project-with-deps') (main (project :sub-project-with-deps))"
+        result.output.contains "project(':sub-project-with-deps') <-- main"
         result.output.contains "project(':sub-project-no-deps')"
     }