Grab outgoing configuration artifacts instead of jar task output (#341)

revapi should now work seamlessly in projects that also apply `com.palantir.shadow-jar`

Author: iamdanfox

changelog/@unreleased/pr-341.v2.yml

@@ -0,0 +1,5 @@
+type: fix
+fix:
+  description: revapi should now work seamlessly in projects that also apply `com.palantir.shadow-jar`
+  links:
+  - https://github.com/palantir/gradle-revapi/pull/341

src/main/java/com/palantir/gradle/revapi/RevapiPlugin.java

@@ -79,10 +79,12 @@ public void apply(Project project) {
 
                     task.getAcceptedBreaks().set(acceptedBreaks(project, configManager, extension.oldGroupAndName()));
 
-                    FileCollection thisJarFile = project.getTasks()
-                            .withType(Jar.class)
-                            .getByName(JavaPlugin.JAR_TASK_NAME)
-                            .getOutputs()
+                    // we don't want to just grab the output of the 'jar' task, because peiple using
+                    // 'com.palantir.shadow-jar' actually publish the output of a different task: 'shadowJar'
+                    FileCollection thisJarFile = project.getConfigurations()
+                            .getByName(JavaPlugin.RUNTIME_ELEMENTS_CONFIGURATION_NAME)
+                            .getOutgoing()
+                            .getArtifacts()
                             .getFiles();
 
                     FileCollection otherProjectsOutputs = revapiNewApiElements