Address some review feedback

Author: breskeby

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/ProjectSubscribeBuildService.java

@@ -10,21 +10,31 @@
 package org.elasticsearch.gradle.internal;
 
 import org.gradle.api.Project;
+import org.gradle.api.provider.Provider;
+import org.gradle.api.provider.ProviderFactory;
 import org.gradle.api.services.BuildService;
 import org.gradle.api.services.BuildServiceParameters;
 
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 
+import javax.inject.Inject;
+
 public abstract class ProjectSubscribeBuildService implements BuildService<BuildServiceParameters.None> {
 
     public static final String TRANSPORT_REFERENCES_TOPIC = "transportReferences";
+    private final ProviderFactory providerFactory;
 
     private Map<String, Collection<String>> versionsByTopic = new HashMap<>();
 
-    public Collection<String> getProjectsByTopic(String topic) {
-        return versionsByTopic.get(topic);
+    @Inject
+    public ProjectSubscribeBuildService(ProviderFactory providerFactory) {
+        this.providerFactory = providerFactory;
+    }
+
+    public Provider<Collection<String>> getProjectsByTopic(String topic) {
+        return providerFactory.provider(() -> versionsByTopic.computeIfAbsent(topic, k -> new java.util.LinkedHashSet<>()));
     }
 
     public void registerProjectForTopic(String topic, Project project) {

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/transport/TransportVersionResourcesPlugin.java

@@ -45,7 +45,8 @@ public void apply(Project project) {
             c.defaultDependencies(t -> {
                 psService.get()
                     .getProjectsByTopic(TRANSPORT_REFERENCES_TOPIC)
-                    .forEach(p -> { t.add(depsHandler.project(Map.of("path", p))); });
+                    .get()
+                    .forEach(path -> t.add(depsHandler.project(Map.of("path", path))));
             });
         });
 

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/transport/ValidateTransportVersionReferencesTask.java

@@ -20,6 +20,7 @@
 import org.gradle.api.tasks.PathSensitive;
 import org.gradle.api.tasks.PathSensitivity;
 import org.gradle.api.tasks.TaskAction;
+import org.gradle.api.tasks.VerificationException;
 import org.gradle.api.tasks.VerificationTask;
 
 import java.io.IOException;
@@ -52,7 +53,7 @@ public void validateTransportVersions() throws IOException {
 
         for (var tvReference : TransportVersionReference.listFromFile(namesFile)) {
             if (resources.referableDefinitionExists(tvReference.name()) == false) {
-                throw new RuntimeException(
+                throw new VerificationException(
                     "TransportVersion.fromName(\""
                         + tvReference.name()
                         + "\") was used at "

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/transport/ValidateTransportVersionResourcesTask.java

@@ -22,6 +22,7 @@
 import org.gradle.api.tasks.PathSensitive;
 import org.gradle.api.tasks.PathSensitivity;
 import org.gradle.api.tasks.TaskAction;
+import org.gradle.api.tasks.VerificationException;
 import org.gradle.api.tasks.VerificationTask;
 
 import java.io.IOException;
@@ -256,11 +257,11 @@ private void validateBase(int base, List<IdAndDefinition> ids) {
 
     private void throwDefinitionFailure(TransportVersionDefinition definition, String message) {
         Path relativePath = getResources().get().getReferableDefinitionRepositoryPath(definition);
-        throw new IllegalStateException("Transport version definition file [" + relativePath + "] " + message);
+        throw new VerificationException("Transport version definition file [" + relativePath + "] " + message);
     }
 
     private void throwUpperBoundFailure(TransportVersionUpperBound upperBound, String message) {
         Path relativePath = getResources().get().getUpperBoundRepositoryPath(upperBound);
-        throw new IllegalStateException("Transport version upper bound file [" + relativePath + "] " + message);
+        throw new VerificationException("Transport version upper bound file [" + relativePath + "] " + message);
     }
 }