Only wrap exceptions when necessary in ArC subclassing

ext/arc/processor/src/main/java/org/jboss/protean/arc/processor/SubclassGenerator.java

@@ -65,6 +65,10 @@
  */
 public class SubclassGenerator extends AbstractGenerator {
 
+    private static final DotName JAVA_LANG_THROWABLE = DotNames.create(Throwable.class.getName());
+    private static final DotName JAVA_LANG_EXCEPTION = DotNames.create(Exception.class.getName());
+    private static final DotName JAVA_LANG_RUNTIME_EXCEPTION = DotNames.create(RuntimeException.class.getName());
+
     static final String SUBCLASS_SUFFIX = "_Subclass";
 
     private final Predicate<DotName> applicationClassPredicate;
@@ -264,14 +268,40 @@ private void createForwardingMethod(ClassOutput classOutput, BeanInfo bean, Meth
                         method.parameters().stream().map(p -> p.name().toString()).collect(Collectors.toList()).toArray(new String[0])),
                 forwardMethod.getThis(), superParamHandles);
         funcBytecode.returnValue(superResult != null ? superResult : funcBytecode.loadNull());
+        for (Type declaredException : method.exceptions()) {
+            forwardMethod.addException(declaredException.name().toString());
+        }
 
         // InvocationContext
         // (java.lang.String) InvocationContextImpl.aroundInvoke(this, methods.get("m1"), params, interceptorChains.get("m1"), forward).proceed()
         TryBlock tryCatch = forwardMethod.tryBlock();
-        // catch (Exception e)
-        CatchBlockCreator exception = tryCatch.addCatch(Exception.class);
-        // throw new RuntimeException(e)
-        exception.throwException(RuntimeException.class, "Error invoking subclass", exception.getCaughtException());
+        // catch exceptions declared on the original method
+        boolean addCatchRuntimeException = true;
+        boolean addCatchException = true;
+        for (Type declaredException : method.exceptions()) {
+            CatchBlockCreator catchDeclaredException = tryCatch.addCatch(declaredException.name().toString());
+            catchDeclaredException.throwException(catchDeclaredException.getCaughtException());
+
+            if (JAVA_LANG_RUNTIME_EXCEPTION.equals(declaredException.name()) ||
+                    JAVA_LANG_THROWABLE.equals(declaredException.name())) {
+                addCatchRuntimeException = false;
+            }
+            if (JAVA_LANG_EXCEPTION.equals(declaredException.name()) ||
+                    JAVA_LANG_THROWABLE.equals(declaredException.name())) {
+                addCatchException = false;
+            }
+        }
+        // catch (RuntimeException e) if not already caught
+        if (addCatchRuntimeException) {
+            CatchBlockCreator catchRuntimeException = tryCatch.addCatch(RuntimeException.class);
+            catchRuntimeException.throwException(catchRuntimeException.getCaughtException());
+        }
+        // now catch the rest (Exception e) if not already caught
+        if (addCatchException) {
+            CatchBlockCreator catchOtherExceptions = tryCatch.addCatch(Exception.class);
+            // and wrap them in a new RuntimeException(e)
+            catchOtherExceptions.throwException(RuntimeException.class, "Error invoking subclass method", catchOtherExceptions.getCaughtException());
+        }
         // InvocationContextImpl.aroundInvoke(this, methods.get("m1"), params, interceptorChains.get("m1"), forward)
         ResultHandle methodIdHandle = tryCatch.load(methodId);
         ResultHandle interceptedMethodHandle = tryCatch.invokeInterfaceMethod(MethodDescriptors.MAP_GET,

ext/arc/tests/src/test/java/org/jboss/protean/arc/test/interceptors/exceptionhandling/ExceptionHandlingBean.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jboss.protean.arc.test.interceptors.exceptionhandling;
+
+import javax.enterprise.context.Dependent;
+
+@Dependent
+public class ExceptionHandlingBean {
+
+    public ExceptionHandlingBean() {
+    }
+
+    @ExceptionHandlingInterceptorBinding
+    void foo(ExceptionHandlingCase exceptionHandlingCase) throws MyDeclaredException {
+        switch (exceptionHandlingCase) {
+        case DECLARED_EXCEPTION:
+            throw new MyDeclaredException();
+        case RUNTIME_EXCEPTION:
+            throw new MyRuntimeException();
+        case OTHER_EXCEPTIONS:
+            // this case should be handled by the interceptor
+            break;
+        }
+    }
+
+    @ExceptionHandlingInterceptorBinding
+    void bar() throws Exception {
+        throw new Exception();
+    }
+
+    @ExceptionHandlingInterceptorBinding
+    void baz() throws RuntimeException {
+        throw new RuntimeException();
+    }
+
+    Integer fooNotIntercepted() {
+        return 1;
+    }
+}

ext/arc/tests/src/test/java/org/jboss/protean/arc/test/interceptors/exceptionhandling/ExceptionHandlingCase.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jboss.protean.arc.test.interceptors.exceptionhandling;
+
+public enum ExceptionHandlingCase {
+    DECLARED_EXCEPTION,
+    RUNTIME_EXCEPTION,
+    OTHER_EXCEPTIONS;
+}

ext/arc/tests/src/test/java/org/jboss/protean/arc/test/interceptors/exceptionhandling/ExceptionHandlingInterceptor.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jboss.protean.arc.test.interceptors.exceptionhandling;
+
+import javax.annotation.Priority;
+import javax.interceptor.AroundInvoke;
+import javax.interceptor.Interceptor;
+import javax.interceptor.InvocationContext;
+
+@ExceptionHandlingInterceptorBinding
+@Priority(1)
+@Interceptor
+public class ExceptionHandlingInterceptor {
+
+    @AroundInvoke
+    Object intercept(InvocationContext ctx) throws Exception {
+        if (ctx.getParameters()[0] == ExceptionHandlingCase.OTHER_EXCEPTIONS) {
+            throw new MyOtherException();
+        }
+        return ctx.proceed();
+    }
+}

ext/arc/tests/src/test/java/org/jboss/protean/arc/test/interceptors/exceptionhandling/ExceptionHandlingInterceptorBinding.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jboss.protean.arc.test.interceptors.exceptionhandling;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import javax.interceptor.InterceptorBinding;
+
+@Target({ TYPE, METHOD })
+@Retention(RUNTIME)
+@Documented
+@InterceptorBinding
+public @interface ExceptionHandlingInterceptorBinding {
+}

ext/arc/tests/src/test/java/org/jboss/protean/arc/test/interceptors/exceptionhandling/InterceptorExceptionHandlingTest.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jboss.protean.arc.test.interceptors.exceptionhandling;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import org.jboss.protean.arc.Arc;
+import org.jboss.protean.arc.Subclass;
+import org.jboss.protean.arc.test.ArcTestContainer;
+import org.junit.Rule;
+import org.junit.Test;
+
+public class InterceptorExceptionHandlingTest {
+
+    @Rule
+    public ArcTestContainer container = new ArcTestContainer(ExceptionHandlingBean.class,
+            ExceptionHandlingInterceptor.class, ExceptionHandlingInterceptorBinding.class);
+
+    @Test(expected = MyDeclaredException.class)
+    public void testProperlyThrowsDeclaredExceptions() throws MyDeclaredException {
+        ExceptionHandlingBean exceptionHandlingBean = Arc.container().instance(ExceptionHandlingBean.class).get();
+
+        assertTrue(exceptionHandlingBean instanceof Subclass);
+
+        exceptionHandlingBean.foo(ExceptionHandlingCase.DECLARED_EXCEPTION);
+    }
+
+    @Test(expected = MyRuntimeException.class)
+    public void testProperlyThrowsRuntimeExceptions() throws MyDeclaredException {
+        ExceptionHandlingBean exceptionHandlingBean = Arc.container().instance(ExceptionHandlingBean.class).get();
+
+        assertTrue(exceptionHandlingBean instanceof Subclass);
+
+        exceptionHandlingBean.foo(ExceptionHandlingCase.RUNTIME_EXCEPTION);
+    }
+
+    @Test
+    public void testWrapsOtherExceptions() throws MyDeclaredException {
+        try {
+            ExceptionHandlingBean exceptionHandlingBean = Arc.container().instance(ExceptionHandlingBean.class).get();
+
+            assertTrue(exceptionHandlingBean instanceof Subclass);
+
+            exceptionHandlingBean.foo(ExceptionHandlingCase.OTHER_EXCEPTIONS);
+            fail("The method should have thrown a RuntimeException wrapping a MyOtherException but didn't throw any exception.");
+        } catch (RuntimeException e) {
+            // Let's check the cause is consistent with what we except.
+            assertEquals(MyOtherException.class, e.getCause().getClass());
+        } catch (Exception e) {
+            fail("The method should have thrown a RuntimeException wrapping a MyOtherException but threw: " + e);
+        }
+    }
+
+    @Test(expected = Exception.class)
+    public void testThrowsException() throws Exception {
+        ExceptionHandlingBean exceptionHandlingBean = Arc.container().instance(ExceptionHandlingBean.class).get();
+
+        assertTrue(exceptionHandlingBean instanceof Subclass);
+
+        exceptionHandlingBean.bar();
+    }
+
+    @Test(expected = RuntimeException.class)
+    public void testThrowsRuntimeException() {
+        ExceptionHandlingBean exceptionHandlingBean = Arc.container().instance(ExceptionHandlingBean.class).get();
+
+        assertTrue(exceptionHandlingBean instanceof Subclass);
+
+        exceptionHandlingBean.baz();
+    }
+}

ext/arc/tests/src/test/java/org/jboss/protean/arc/test/interceptors/exceptionhandling/MyDeclaredException.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jboss.protean.arc.test.interceptors.exceptionhandling;
+
+public class MyDeclaredException extends Exception {
+}

ext/arc/tests/src/test/java/org/jboss/protean/arc/test/interceptors/exceptionhandling/MyOtherException.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jboss.protean.arc.test.interceptors.exceptionhandling;
+
+public class MyOtherException extends Exception {
+}

ext/arc/tests/src/test/java/org/jboss/protean/arc/test/interceptors/exceptionhandling/MyRuntimeException.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jboss.protean.arc.test.interceptors.exceptionhandling;
+
+public class MyRuntimeException extends RuntimeException {
+}