incorrectly invoked factory methods now result in exceptions with more descriptive messages (SPR-5475)

org.springframework.beans/src/test/java/org/springframework/beans/factory/Spr5475Tests.java

@@ -0,0 +1,93 @@
+package org.springframework.beans.factory;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.fail;
+import static org.springframework.beans.factory.support.BeanDefinitionBuilder.rootBeanDefinition;
+
+import org.junit.Test;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.ConstructorArgumentValues;
+import org.springframework.beans.factory.support.DefaultListableBeanFactory;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+
+/**
+ * SPR-5475 exposed the fact that the error message displayed when incorrectly
+ * invoking a factory method is not instructive to the user and rather misleading.
+ *
+ * @author Chris Beams
+ */
+public class Spr5475Tests {
+
+	@Test
+	public void noArgFactoryMethodInvokedWithOneArg() {
+		assertExceptionMessageForMisconfiguredFactoryMethod(
+				rootBeanDefinition(Foo.class)
+					.setFactoryMethod("noArgFactory")
+					.addConstructorArgValue("bogusArg").getBeanDefinition(),
+				"Error creating bean with name 'foo': No matching factory method found: factory method 'noArgFactory(String)'. " +
+				"Check that a method with the specified name and arguments exists and that it is static.");
+	}
+
+	@Test
+	public void noArgFactoryMethodInvokedWithTwoArgs() {
+		assertExceptionMessageForMisconfiguredFactoryMethod(
+				rootBeanDefinition(Foo.class)
+					.setFactoryMethod("noArgFactory")
+					.addConstructorArgValue("bogusArg1")
+					.addConstructorArgValue("bogusArg2".getBytes()).getBeanDefinition(),
+				"Error creating bean with name 'foo': No matching factory method found: factory method 'noArgFactory(String,byte[])'. " +
+				"Check that a method with the specified name and arguments exists and that it is static.");
+	}
+
+	@Test
+	public void noArgFactoryMethodInvokedWithTwoArgsAndTypesSpecified() {
+		RootBeanDefinition def = new RootBeanDefinition(Foo.class);
+		def.setFactoryMethodName("noArgFactory");
+		ConstructorArgumentValues cav = new ConstructorArgumentValues();
+		cav.addIndexedArgumentValue(0, "bogusArg1", CharSequence.class.getName());
+		cav.addIndexedArgumentValue(1, "bogusArg2".getBytes());
+		def.setConstructorArgumentValues(cav);
+
+		assertExceptionMessageForMisconfiguredFactoryMethod(
+				def,
+				"Error creating bean with name 'foo': No matching factory method found: factory method 'noArgFactory(CharSequence,byte[])'. " +
+				"Check that a method with the specified name and arguments exists and that it is static.");
+	}
+
+	private void assertExceptionMessageForMisconfiguredFactoryMethod(BeanDefinition bd, String expectedMessage) {
+		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
+		factory.registerBeanDefinition("foo", bd);
+
+		try {
+			factory.preInstantiateSingletons();
+			fail("should have failed with BeanCreationException due to incorrectly invoked factory method");
+		} catch (BeanCreationException ex) {
+			assertThat(ex.getMessage(), equalTo(expectedMessage));
+		}
+	}
+
+	@Test
+	public void singleArgFactoryMethodInvokedWithNoArgs() {
+		// calling a factory method that accepts arguments without any arguments emits an exception unlike cases
+		// where a no-arg factory method is called with arguments. Adding this test just to document the difference
+		assertExceptionMessageForMisconfiguredFactoryMethod(
+				rootBeanDefinition(Foo.class)
+					.setFactoryMethod("singleArgFactory").getBeanDefinition(),
+				"Error creating bean with name 'foo': " +
+				"Unsatisfied dependency expressed through constructor argument with index 0 of type [java.lang.String]: " +
+				"Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?");
+	}
+
+
+	static class Foo {
+		static Foo noArgFactory() {
+			return new Foo();
+		}
+
+		static Foo singleArgFactory(String arg) {
+			return new Foo();
+		}
+	}
+
+}