fix: returns exception message from invocation

Author: jk-idealo

src/main/java/com/github/nylle/javafixture/instantiation/FactoryMethodInstantiator.java

@@ -5,6 +5,7 @@
 import com.github.nylle.javafixture.SpecimenType;
 
 import java.lang.annotation.Annotation;
+import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
@@ -33,6 +34,8 @@ public Result<T> invoke(SpecimenFactory specimenFactory, CustomizationContext cu
                 arguments.add(specimen.create(customizationContext, new Annotation[0]));
             }
             return Result.of((T) factoryMethod.invoke(null, arguments.toArray()));
+        } catch (InvocationTargetException ex) {
+            return Result.empty(ex.getTargetException().getMessage());
         } catch (Exception ex) {
             return Result.empty(ex.getMessage());
         }

src/test/java/com/github/nylle/javafixture/instantiation/ConstructorInstantiatorTest.java

@@ -88,7 +88,8 @@ void ignoredConstructorArgsAreRespected() throws NoSuchMethodException {
     }
 
     @Test
-    void xxx() throws NoSuchMethodException {
+    @DisplayName("returns exception message from invocation when constructor fails")
+    void resolveTargetExceptionMessage() throws NoSuchMethodException {
         var sut = ConstructorInstantiator.create(ConstructorExceptionAndNoFactoryMethod.class.getConstructor());
 
         var actual = sut.invoke(new SpecimenFactory(new Context(Configuration.configure())), new CustomizationContext(List.of(), Map.of(), true));

src/test/java/com/github/nylle/javafixture/instantiation/FactoryMethodInstantiatorTest.java

@@ -8,6 +8,7 @@
 import com.github.nylle.javafixture.testobjects.factorymethod.FactoryMethodWithGenericArgument;
 import com.github.nylle.javafixture.testobjects.factorymethod.FactoryMethodWithoutArgument;
 import com.github.nylle.javafixture.testobjects.factorymethod.GenericClassWithFactoryMethodWithoutArgument;
+import com.github.nylle.javafixture.testobjects.withconstructor.ConstructorExceptionAndThrowingFactoryMethod;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
@@ -93,4 +94,14 @@ void genericNoArgumentFactoryMethod() throws NoSuchMethodException {
         assertThat(actual.getValue()).isNotNull();
         assertThat(actual.getValue().getValue()).isEqualTo(42);
     }
+
+    @Test
+    @DisplayName("returns exception message from invocation when factory method fails")
+    void resolveTargetExceptionMessage() throws NoSuchMethodException {
+        var sut = FactoryMethodInstantiator.<FactoryMethodWithoutArgument>create(ConstructorExceptionAndThrowingFactoryMethod.class.getDeclaredMethod("factoryMethod"), fromClass(ConstructorExceptionAndThrowingFactoryMethod.class));
+
+        var actual = sut.invoke(new SpecimenFactory(new Context(Configuration.configure())), noContext());
+
+        assertThat(actual.getMessage()).isEqualTo("factory method exception expected for tests");
+    }
 }