[Core] Support custom UUID generators in test runners (#2926)

With #2703 a faster UUID generator was introduced. And while the
configuration options were added, they were not actually used by
`cucumber-junit`, `cucumber-junit-platform-engine` and
`cucumber-testng`.

Author: mpkorstanje

.revapi/api-changes.json

@@ -69,6 +69,26 @@
       }
     }
   ],
+  "7.20.0": [
+    {
+      "extension": "revapi.differences",
+      "id": "intentional-api-changes",
+      "ignore": true,
+      "configuration": {
+        "differences": [
+          {
+            "ignore": true,
+            "code": "java.method.visibilityIncreased",
+            "old": "method io.cucumber.core.eventbus.UuidGenerator io.cucumber.core.runtime.UuidGeneratorServiceLoader::loadUuidGenerator()",
+            "new": "method io.cucumber.core.eventbus.UuidGenerator io.cucumber.core.runtime.UuidGeneratorServiceLoader::loadUuidGenerator()",
+            "oldVisibility": "package",
+            "newVisibility": "public",
+            "justification": "Expose internal API to other internal components"
+          }
+        ]
+      }
+    }
+  ],
   "internal": [
     {
       "extension": "revapi.differences",

CHANGELOG.md

@@ -10,6 +10,14 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- [JUnit Platform Engine] Enable use of custom UUID generators ([#2926](https://github.com/cucumber/cucumber-jvm/pull/2926) M.P. Korstanje)
+- [JUnit] Enable use of custom UUID generators ([#2926](https://github.com/cucumber/cucumber-jvm/pull/2926) M.P. Korstanje)
+- [TestNG] Enable use of custom UUID generators ([#2926](https://github.com/cucumber/cucumber-jvm/pull/2926) M.P. Korstanje)
+
+### Fixed
+- [Core] Use custom UUID generators for hooks ([#2926](https://github.com/cucumber/cucumber-jvm/pull/2926) M.P. Korstanje)
+
 
 ## [7.19.0] - 2024-09-19
 ### Changed

cucumber-core/README.md

@@ -53,7 +53,8 @@ cucumber.plugin=                # comma separated plugin strings.
 cucumber.object-factory=        # object factory class name.
                                 # example: com.example.MyObjectFactory
 
-cucumber.uuid-generator=        # UUID generator class name.
+cucumber.uuid-generator         # uuid generator class name of a registered service provider.
+                                # default: io.cucumber.core.eventbus.RandomUuidGenerator
                                 # example: com.example.MyUuidGenerator
 
 cucumber.publish.enabled        # true or false. default: false
@@ -89,12 +90,13 @@ Cucumber emits events on an event bus in many cases:
 - during the feature file parsing
 - when the test scenarios are executed
 
-An event has a UUID. The UUID generator can be configured using the `cucumber.uuid-generator` property:
+An event has a UUID. The UUID generator can be configured using the
+`cucumber.uuid-generator` property:
 
 | UUID generator                                      | Features                                | Performance [Millions UUID/second] | Typical usage example                                                                                                                                                                                                                                                          | 
 |-----------------------------------------------------|-----------------------------------------|------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | io.cucumber.core.eventbus.RandomUuidGenerator       | Thread-safe, collision-free, multi-jvm  | ~1                                 | Reports may be generated on different JVMs at the same time. A typical example would be one suite that tests against Firefox and another against Safari. The exact browser is configured through a property. These are then executed concurrently on different Gitlab runners. |
-| io.cucumber.core.eventbus.IncrementingUuidGenerator | Thread-safe, collision-free, single-jvm | ~130                               | Reports are generated on a single JVM                                                                                                                                                                                                                                          |
+| io.cucumber.core.eventbus.IncrementingUuidGenerator | Thread-safe, collision-free, single-jvm | ~130                               | Reports are generated on a single JVM in a single execution of Cucumber.                                                                                                                                                                                                       |
 
 The performance gain on real projects depends on the feature size.
 

cucumber-core/src/main/java/io/cucumber/core/eventbus/IncrementingUuidGenerator.java

@@ -10,20 +10,20 @@
  * Thread-safe and collision-free UUID generator for single JVM. This is a
  * sequence generator and each instance has its own counter. This generator is
  * about 100 times faster than #RandomUuidGenerator.
- *
- * Properties:
- * - thread-safe
- * - collision-free in the same classloader
- * - almost collision-free in different classloaders / JVMs
- * - UUIDs generated using the instances from the same classloader are sortable
- *
- * UUID version 8 (custom) / variant 2 <a href=
- * "https://www.ietf.org/archive/id/draft-peabody-dispatch-new-uuid-format-04.html#name-uuid-version-8">...</a>
- * <!-- @formatter:off -->
+ * <p>
+ * Properties: - thread-safe - collision-free in the same classloader - almost
+ * collision-free in different classloaders / JVMs - UUIDs generated using the
+ * instances from the same classloader are sortable
+ * <p>
+ * <a href=
+ * "https://www.ietf.org/archive/id/draft-peabody-dispatch-new-uuid-format-04.html#name-uuid-version-8">UUID
+ * version 8 (custom) / variant 2 </a>
+ * 
+ * <pre>
  * |       40 bits      |      8 bits    |  4 bits |    12 bits    |  2 bits | 62 bits |
  * | -------------------| -------------- | ------- | ------------- | ------- | ------- |
  * | LSBs of epoch-time | sessionCounter | version | classloaderId | variant | counter |
- * <!-- @formatter:on -->
+ * </pre>
  */
 public class IncrementingUuidGenerator implements UuidGenerator {
     /**
@@ -84,7 +84,7 @@ public class IncrementingUuidGenerator implements UuidGenerator {
      * classloaderId which produces about 1% collision rate on the
      * classloaderId, and thus can have UUID collision if the epoch-time,
      * session counter and counter have the same values).
-     * 
+     *
      * @param classloaderId the new classloaderId (only the least significant 12
      *                      bits are used)
      * @see                 IncrementingUuidGenerator#classloaderId

cucumber-core/src/main/java/io/cucumber/core/runner/CachingGlue.java

@@ -105,25 +105,25 @@ public void addStepDefinition(StepDefinition stepDefinition) {
 
     @Override
     public void addBeforeHook(HookDefinition hookDefinition) {
-        beforeHooks.add(CoreHookDefinition.create(hookDefinition));
+        beforeHooks.add(CoreHookDefinition.create(hookDefinition, bus::generateId));
         beforeHooks.sort(HOOK_ORDER_ASCENDING);
     }
 
     @Override
     public void addAfterHook(HookDefinition hookDefinition) {
-        afterHooks.add(CoreHookDefinition.create(hookDefinition));
+        afterHooks.add(CoreHookDefinition.create(hookDefinition, bus::generateId));
         afterHooks.sort(HOOK_ORDER_ASCENDING);
     }
 
     @Override
     public void addBeforeStepHook(HookDefinition hookDefinition) {
-        beforeStepHooks.add(CoreHookDefinition.create(hookDefinition));
+        beforeStepHooks.add(CoreHookDefinition.create(hookDefinition, bus::generateId));
         beforeStepHooks.sort(HOOK_ORDER_ASCENDING);
     }
 
     @Override
     public void addAfterStepHook(HookDefinition hookDefinition) {
-        afterStepHooks.add(CoreHookDefinition.create(hookDefinition));
+        afterStepHooks.add(CoreHookDefinition.create(hookDefinition, bus::generateId));
         afterStepHooks.sort(HOOK_ORDER_ASCENDING);
     }
 

cucumber-core/src/main/java/io/cucumber/core/runner/CoreHookDefinition.java

@@ -11,6 +11,7 @@
 import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
+import java.util.function.Supplier;
 
 import static java.util.Objects.requireNonNull;
 
@@ -33,13 +34,13 @@ private CoreHookDefinition(UUID id, HookDefinition delegate) {
         }
     }
 
-    static CoreHookDefinition create(HookDefinition hookDefinition) {
+    static CoreHookDefinition create(HookDefinition hookDefinition, Supplier<UUID> uuidGenerator) {
         // Ideally we would avoid this by keeping the scenario scoped
         // glue in a different bucket from the globally scoped glue.
         if (hookDefinition instanceof ScenarioScoped) {
-            return new ScenarioScopedCoreHookDefinition(hookDefinition);
+            return new ScenarioScopedCoreHookDefinition(uuidGenerator.get(), hookDefinition);
         }
-        return new CoreHookDefinition(UUID.randomUUID(), hookDefinition);
+        return new CoreHookDefinition(uuidGenerator.get(), hookDefinition);
     }
 
     void execute(TestCaseState scenario) {
@@ -72,8 +73,8 @@ String getTagExpression() {
 
     static class ScenarioScopedCoreHookDefinition extends CoreHookDefinition implements ScenarioScoped {
 
-        private ScenarioScopedCoreHookDefinition(HookDefinition delegate) {
-            super(UUID.randomUUID(), delegate);
+        private ScenarioScopedCoreHookDefinition(UUID id, HookDefinition delegate) {
+            super(id, delegate);
         }
 
         @Override

cucumber-core/src/main/java/io/cucumber/core/runtime/UuidGeneratorServiceLoader.java

@@ -38,7 +38,7 @@ public UuidGeneratorServiceLoader(Supplier<ClassLoader> classLoaderSupplier, Opt
         this.options = requireNonNull(options);
     }
 
-    UuidGenerator loadUuidGenerator() {
+    public UuidGenerator loadUuidGenerator() {
         Class<? extends UuidGenerator> objectFactoryClass = options.getUuidGeneratorClass();
         ClassLoader classLoader = classLoaderSupplier.get();
         ServiceLoader<UuidGenerator> loader = ServiceLoader.load(UuidGenerator.class, classLoader);

cucumber-junit-platform-engine/README.md

@@ -373,6 +373,10 @@ cucumber.junit-platform.naming-strategy.long.example-name=     # number or pickl
 
 cucumber.plugin=                                               # comma separated plugin strings.
                                                                # example: pretty, json:path/to/report.json
+
+cucumber.uuid-generator                                        # uuid generator class name of a registered service provider.
+                                                               # default: io.cucumber.core.eventbus.RandomUuidGenerator
+                                                               # example: com.example.MyUuidGenerator
  
 cucumber.object-factory=                                       # object factory class name.
                                                                # example: com.example.MyObjectFactory

cucumber-junit-platform-engine/src/main/java/io/cucumber/junit/platform/engine/CucumberEngineExecutionContext.java

@@ -19,12 +19,12 @@
 import io.cucumber.core.runtime.ThreadLocalObjectFactorySupplier;
 import io.cucumber.core.runtime.ThreadLocalRunnerSupplier;
 import io.cucumber.core.runtime.TimeServiceEventBus;
+import io.cucumber.core.runtime.UuidGeneratorServiceLoader;
 import org.apiguardian.api.API;
 import org.junit.platform.engine.ConfigurationParameters;
 import org.junit.platform.engine.support.hierarchical.EngineExecutionContext;
 
 import java.time.Clock;
-import java.util.UUID;
 import java.util.function.Supplier;
 
 import static io.cucumber.core.runtime.SynchronizedEventBus.synchronize;
@@ -48,8 +48,10 @@ CucumberEngineOptions getOptions() {
 
     private CucumberExecutionContext createCucumberExecutionContext() {
         Supplier<ClassLoader> classLoader = CucumberEngineExecutionContext.class::getClassLoader;
+        UuidGeneratorServiceLoader uuidGeneratorServiceLoader = new UuidGeneratorServiceLoader(classLoader, options);
+        EventBus bus = synchronize(
+            new TimeServiceEventBus(Clock.systemUTC(), uuidGeneratorServiceLoader.loadUuidGenerator()));
         ObjectFactoryServiceLoader objectFactoryServiceLoader = new ObjectFactoryServiceLoader(classLoader, options);
-        EventBus bus = synchronize(new TimeServiceEventBus(Clock.systemUTC(), UUID::randomUUID));
         Plugins plugins = new Plugins(new PluginFactory(), options);
         ExitStatus exitStatus = new ExitStatus(options);
         plugins.addPlugin(exitStatus);

cucumber-junit-platform-engine/src/main/java/io/cucumber/junit/platform/engine/FeatureResolver.java

@@ -1,5 +1,6 @@
 package io.cucumber.junit.platform.engine;
 
+import io.cucumber.core.eventbus.UuidGenerator;
 import io.cucumber.core.feature.FeatureIdentifier;
 import io.cucumber.core.feature.FeatureParser;
 import io.cucumber.core.feature.FeatureWithLines;
@@ -9,6 +10,7 @@
 import io.cucumber.core.logging.LoggerFactory;
 import io.cucumber.core.resource.ClassLoaders;
 import io.cucumber.core.resource.ResourceScanner;
+import io.cucumber.core.runtime.UuidGeneratorServiceLoader;
 import io.cucumber.junit.platform.engine.NodeDescriptor.ExamplesDescriptor;
 import io.cucumber.junit.platform.engine.NodeDescriptor.PickleDescriptor;
 import io.cucumber.junit.platform.engine.NodeDescriptor.RuleDescriptor;
@@ -28,8 +30,8 @@
 
 import java.net.URI;
 import java.util.List;
-import java.util.UUID;
 import java.util.function.Predicate;
+import java.util.function.Supplier;
 import java.util.stream.Stream;
 
 import static java.util.Comparator.comparing;
@@ -38,11 +40,7 @@ final class FeatureResolver {
 
     private static final Logger log = LoggerFactory.getLogger(FeatureResolver.class);
 
-    private final CachingFeatureParser featureParser = new CachingFeatureParser(new FeatureParser(UUID::randomUUID));
-    private final ResourceScanner<Feature> featureScanner = new ResourceScanner<>(
-        ClassLoaders::getDefaultClassLoader,
-        FeatureIdentifier::isFeature,
-        featureParser::parseResource);
+    private final ResourceScanner<Feature> featureScanner;
 
     private final CucumberEngineDescriptor engineDescriptor;
     private final Predicate<String> packageFilter;
@@ -56,7 +54,21 @@ private FeatureResolver(
         this.parameters = parameters;
         this.engineDescriptor = engineDescriptor;
         this.packageFilter = packageFilter;
-        this.namingStrategy = new CucumberEngineOptions(parameters).namingStrategy();
+        CucumberEngineOptions options = new CucumberEngineOptions(parameters);
+        this.namingStrategy = options.namingStrategy();
+        CachingFeatureParser featureParser = createFeatureParser(options);
+        this.featureScanner = new ResourceScanner<>(
+            ClassLoaders::getDefaultClassLoader,
+            FeatureIdentifier::isFeature,
+            featureParser::parseResource);
+    }
+
+    private static CachingFeatureParser createFeatureParser(CucumberEngineOptions options) {
+        Supplier<ClassLoader> classLoader = FeatureResolver.class::getClassLoader;
+        UuidGeneratorServiceLoader uuidGeneratorServiceLoader = new UuidGeneratorServiceLoader(classLoader, options);
+        UuidGenerator uuidGenerator = uuidGeneratorServiceLoader.loadUuidGenerator();
+        FeatureParser featureParser = new FeatureParser(uuidGenerator::generateId);
+        return new CachingFeatureParser(featureParser);
     }
 
     static FeatureResolver create(