Fail @ParameterizedTest if there are no registered ArgumentProviders (#4201)

Resolves #4146.

Author: juliette-derancourt

junit-jupiter-params/src/main/java/org/junit/jupiter/params/ParameterizedTestExtension.java

@@ -14,6 +14,7 @@
 import static org.junit.platform.commons.support.AnnotationSupport.findRepeatableAnnotations;
 
 import java.lang.reflect.Method;
+import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.stream.Stream;
@@ -74,8 +75,13 @@ public Stream<TestTemplateInvocationContext> provideTestTemplateInvocationContex
 		ParameterizedTestNameFormatter formatter = createNameFormatter(extensionContext, methodContext);
 		AtomicLong invocationCount = new AtomicLong(0);
 
+		List<ArgumentsSource> argumentsSources = findRepeatableAnnotations(methodContext.method, ArgumentsSource.class);
+
+		Preconditions.notEmpty(argumentsSources,
+			"Configuration error: You must configure at least one arguments source for this @ParameterizedTest");
+
 		// @formatter:off
-		return findRepeatableAnnotations(methodContext.method, ArgumentsSource.class)
+		return argumentsSources
 				.stream()
 				.map(ArgumentsSource::value)
 				.map(clazz -> ParameterizedTestSpiInstantiator.instantiate(ArgumentsProvider.class, clazz, extensionContext))

jupiter-tests/src/test/java/org/junit/jupiter/params/ParameterizedTestExtensionTests.java

@@ -146,16 +146,23 @@ void throwsExceptionWhenParameterizedTestIsNotInvokedAtLeastOnce() {
 
 	@Test
 	void doesNotThrowExceptionWhenParametrizedTestDoesNotRequireArguments() {
-		var extensionContextWithAnnotatedTestMethod = getExtensionContextReturningSingleMethod(
-			new TestCaseAllowNoArgumentsMethod());
+		var extensionContext = getExtensionContextReturningSingleMethod(new TestCaseAllowNoArgumentsMethod());
 
-		var stream = this.parameterizedTestExtension.provideTestTemplateInvocationContexts(
-			extensionContextWithAnnotatedTestMethod);
+		var stream = this.parameterizedTestExtension.provideTestTemplateInvocationContexts(extensionContext);
 		// cause the stream to be evaluated
 		stream.toArray();
 		stream.close();
 	}
 
+	@Test
+	void throwsExceptionWhenParameterizedTestHasNoArgumentsSource() {
+		var extensionContext = getExtensionContextReturningSingleMethod(new TestCaseWithNoArgumentsSource());
+
+		assertThrows(PreconditionViolationException.class,
+			() -> this.parameterizedTestExtension.provideTestTemplateInvocationContexts(extensionContext),
+			"Configuration error: You must configure at least one arguments source for this @ParameterizedTest");
+	}
+
 	@Test
 	void throwsExceptionWhenArgumentsProviderIsNotStatic() {
 		var extensionContextWithAnnotatedTestMethod = getExtensionContextReturningSingleMethod(
@@ -323,19 +330,36 @@ void method() {
 
 	static class TestCaseWithAnnotatedMethod {
 
-		@SuppressWarnings("JUnitMalformedDeclaration")
 		@ParameterizedTest
+		@ArgumentsSource(ZeroArgumentsProvider.class)
 		void method() {
 		}
 	}
 
 	static class TestCaseAllowNoArgumentsMethod {
 
 		@ParameterizedTest(allowZeroInvocations = true)
+		@ArgumentsSource(ZeroArgumentsProvider.class)
 		void method() {
 		}
 	}
 
+	static class TestCaseWithNoArgumentsSource {
+
+		@ParameterizedTest(allowZeroInvocations = true)
+		@SuppressWarnings("JUnitMalformedDeclaration")
+		void method() {
+		}
+	}
+
+	static class ZeroArgumentsProvider implements ArgumentsProvider {
+
+		@Override
+		public Stream<? extends Arguments> provideArguments(ExtensionContext context) {
+			return Stream.empty();
+		}
+	}
+
 	static class ArgumentsProviderWithCloseHandlerTestCase {
 
 		@ParameterizedTest

jupiter-tests/src/test/java/org/junit/jupiter/params/ParameterizedTestIntegrationTests.java

@@ -457,7 +457,7 @@ void failsWhenArgumentsRequiredButNoneProvided() {
 	}
 
 	@Test
-	void failsWhenArgumentsAreNotRequiredAndNoneProvided() {
+	void doesNotFailWhenArgumentsAreNotRequiredAndNoneProvided() {
 		var result = execute(ZeroArgumentsTestCase.class, "testThatDoesNotRequireArguments", String.class);
 		result.allEvents().assertEventsMatchExactly( //
 			event(engine(), started()), event(container(ZeroArgumentsTestCase.class), started()),
@@ -467,6 +467,15 @@ void failsWhenArgumentsAreNotRequiredAndNoneProvided() {
 			event(engine(), finishedSuccessfully()));
 	}
 
+	@Test
+	void failsWhenNoArgumentsSourceIsDeclared() {
+		var result = execute(ZeroArgumentsTestCase.class, "testThatHasNoArgumentsSource", String.class);
+		result.containerEvents().assertThatEvents() //
+				.haveExactly(1, //
+					event(displayName("testThatHasNoArgumentsSource(String)"), finishedWithFailure(message(
+						"Configuration error: You must configure at least one arguments source for this @ParameterizedTest"))));
+	}
+
 	private EngineExecutionResults execute(DiscoverySelector... selectors) {
 		return EngineTestKit.engine(new JupiterTestEngine()).selectors(selectors).execute();
 	}
@@ -2428,6 +2437,12 @@ void testThatDoesNotRequireArguments(String argument) {
 			fail("This test should not be executed, because no arguments are provided.");
 		}
 
+		@ParameterizedTest(allowZeroInvocations = true)
+		@SuppressWarnings("JUnitMalformedDeclaration")
+		void testThatHasNoArgumentsSource(String argument) {
+			fail("This test should not be executed, because no arguments source is declared.");
+		}
+
 		public static Stream<Arguments> zeroArgumentsProvider() {
 			return Stream.empty();
 		}