Rewrite ExecutorPollutionTest to utilize JUnit5's @testtemplate (#926)

pivovarit · Sep 14, 2024 · a1f4f69 · a1f4f69
1 parent 1ed7bb1
commit a1f4f69
Showing 1 changed file with 82 additions and 31 deletions.
diff --git a/src/test/java/com/pivovarit/collectors/functional/ExecutorPollutionTest.java b/src/test/java/com/pivovarit/collectors/functional/ExecutorPollutionTest.java
@@ -1,9 +1,17 @@
 package com.pivovarit.collectors.functional;
 
 import com.pivovarit.collectors.ParallelCollectors;
-import org.junit.jupiter.api.DynamicTest;
-import org.junit.jupiter.api.TestFactory;
+import org.junit.jupiter.api.TestTemplate;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.extension.Extension;
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.ParameterContext;
+import org.junit.jupiter.api.extension.ParameterResolutionException;
+import org.junit.jupiter.api.extension.ParameterResolver;
+import org.junit.jupiter.api.extension.TestTemplateInvocationContext;
+import org.junit.jupiter.api.extension.TestTemplateInvocationContextProvider;
 
+import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executor;
 import java.util.concurrent.LinkedBlockingQueue;
@@ -15,43 +23,62 @@
 
 import static com.pivovarit.collectors.ParallelCollectors.Batching.parallel;
 import static java.util.stream.Collectors.toList;
-import static java.util.stream.Stream.of;
 
+@ExtendWith(ExecutorPollutionTest.ContextProvider.class)
 class ExecutorPollutionTest {
 
-    @TestFactory
-    Stream<DynamicTest> shouldStartProcessingElementsTests() {
-        return of(
-          shouldNotSubmitMoreTasksThanParallelism((f, e, p) -> ParallelCollectors.parallel(f, e, p), "parallel#1"),
-          shouldNotSubmitMoreTasksThanParallelism((f, __, p) -> ParallelCollectors.parallel(f, p), "parallel#2"),
-          shouldNotSubmitMoreTasksThanParallelism((f, e, p) -> ParallelCollectors.parallel(f, toList(), e, p), "parallel#3"),
-          shouldNotSubmitMoreTasksThanParallelism((f, __, p) -> ParallelCollectors.parallel(f, toList(), p), "parallel#4"),
-          shouldNotSubmitMoreTasksThanParallelism((f, e, p) -> ParallelCollectors.parallelToStream(f, e, p), "parallelToStream#1"),
-          shouldNotSubmitMoreTasksThanParallelism((f, __, p) -> ParallelCollectors.parallelToStream(f, p), "parallelToStream#2"),
-          shouldNotSubmitMoreTasksThanParallelism((f, e, p) -> ParallelCollectors.parallelToOrderedStream(f, e, p), "parallelToOrderedStream#1"),
-          shouldNotSubmitMoreTasksThanParallelism((f, __, p) -> ParallelCollectors.parallelToOrderedStream(f, p), "parallelToOrderedStream#2"),
-          shouldNotSubmitMoreTasksThanParallelism((f, e, p) -> parallel(f, e, p), "parallel#1 (batching)"),
-          shouldNotSubmitMoreTasksThanParallelism((f, e, p) -> parallel(f, toList(), e, p), "parallel#2 (batching)"),
-          shouldNotSubmitMoreTasksThanParallelism((f, e, p) -> ParallelCollectors.Batching.parallelToStream(f, e, p), "parallelToStream (batching)"),
-          shouldNotSubmitMoreTasksThanParallelism((f, e, p) -> ParallelCollectors.Batching.parallelToOrderedStream(f, e, p), "parallelToOrderedStream (batching)")
-        );
+    @TestTemplate
+    void shouldNotPolluteExecutorWhenNoParallelism(CollectorFactory<Integer> collector) {
+        try (var e = warmedUp(new ThreadPoolExecutor(1 , 2, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<>(2)))) {
+
+            var result = Stream.generate(() -> 42)
+              .limit(1000)
+              .collect(collector.apply(i -> i, e, 1));
+
+            switch (result) {
+                case CompletableFuture<?> cf -> cf.join();
+                case Stream<?> s -> s.forEach((__) -> {});
+                default -> throw new IllegalStateException("can't happen");
+            }
+        }
     }
 
-    private static DynamicTest shouldNotSubmitMoreTasksThanParallelism(CollectorFactory<Integer> collector, String name) {
-        return DynamicTest.dynamicTest(name, () -> {
-            try (var e = warmedUp(new ThreadPoolExecutor(2, 2, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<>(2)))) {
+    @TestTemplate
+    void shouldNotPolluteExecutorWhenLimitedParallelism(CollectorFactory<Integer> collector) {
+        try (var e = warmedUp(new ThreadPoolExecutor(2 , 2, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<>(2)))) {
 
-                var result = Stream.generate(() -> 42)
-                  .limit(1000)
-                  .collect(collector.apply(i -> i, e, 2));
+            var result = Stream.generate(() -> 42)
+              .limit(1000)
+              .collect(collector.apply(i -> i, e, 2));
 
-                switch (result) {
-                    case CompletableFuture<?> cf -> cf.join();
-                    case Stream<?> s -> s.forEach((__) -> {});
-                    default -> throw new IllegalStateException("can't happen");
-                }
+            switch (result) {
+                case CompletableFuture<?> cf -> cf.join();
+                case Stream<?> s -> s.forEach((__) -> {});
+                default -> throw new IllegalStateException("can't happen");
             }
-        });
+        }
+    }
+
+    static class ContextProvider implements TestTemplateInvocationContextProvider {
+
+        @Override
+        public boolean supportsTestTemplate(ExtensionContext context) {
+            return true;
+        }
+
+        @Override
+        public Stream<TestTemplateInvocationContext> provideTestTemplateInvocationContexts(ExtensionContext context) {
+            return Stream.of(
+              collector("parallel()", (f, e, p) -> ParallelCollectors.parallel(f, e, p)),
+              collector("parallel(toList())", (f, e, p) -> ParallelCollectors.parallel(f, toList(), e, p)),
+              collector("parallelToStream()", (f, e, p) -> ParallelCollectors.parallelToStream(f, e, p)),
+              collector("parallelToOrderedStream()", (f, e, p) -> ParallelCollectors.parallelToOrderedStream(f, e, p)),
+              collector("parallel() (batching)", (f, e, p) -> parallel(f, e, p)),
+              collector("parallel(toList()) (batching)", (f, e, p) -> parallel(f, toList(), e, p)),
+              collector("parallelToStream() (batching)", (f, e, p) -> ParallelCollectors.Batching.parallelToStream(f, e, p)),
+              collector("parallelToOrderedStream() (batching)", (f, e, p) -> ParallelCollectors.Batching.parallelToOrderedStream(f, e, p))
+            );
+        }
     }
 
     interface CollectorFactory<T> {
@@ -64,4 +91,28 @@ private static ThreadPoolExecutor warmedUp(ThreadPoolExecutor e) {
         }
         return e;
     }
+
+    private static <T> TestTemplateInvocationContext collector(String name, CollectorFactory<T> factory) {
+        return new TestTemplateInvocationContext() {
+            @Override
+            public String getDisplayName(int invocationIndex) {
+                return name + " [" + invocationIndex + "]";
+            }
+
+            @Override
+            public List<Extension> getAdditionalExtensions() {
+                return List.of(new ParameterResolver() {
+                    @Override
+                    public boolean supportsParameter(ParameterContext parameterContext, ExtensionContext extensionContext) throws ParameterResolutionException {
+                        return parameterContext.getParameter().getType().equals(CollectorFactory.class);
+                    }
+
+                    @Override
+                    public Object resolveParameter(ParameterContext parameterContext, ExtensionContext extensionContext) throws ParameterResolutionException {
+                        return factory;
+                    }
+                });
+            }
+        };
+    }
 }