Refactor, comment and reactivate Ajc183Tests.testAnnoStyleDecp_442425

This test was always inactive and did not add any value other than
during development. No it runs, passes and documents the status quo of
  - what was fixed (regression for AJC 1.8.2 core dump fixed in 1.8.3),
  - the current limitations of @DeclareParents and @DeclareMixin
    regarding generic interfaces.

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

1 files changed, 35 insertions, 28 deletions

diff --git a/tests/bugs183/442425/MyAnnotatedController.java b/tests/bugs183/442425/MyAnnotatedController.java
index fab43b835..cafe5bcbc 100644
--- a/tests/bugs183/442425/MyAnnotatedController.java
+++ b/tests/bugs183/442425/MyAnnotatedController.java
@@ -1,37 +1,44 @@
-package de.scrum_master.app;
-
 import java.lang.reflect.Method;
 
 @EntityController
 public class MyAnnotatedController<T> {
-    public void doSomething() {
-        System.out.println("Doing something");
-    }
+  public void doSomething() {
+    System.out.println("Doing something");
+  }
 
-    public static void main(String[] args) {
-        // Use class type directly so as to call its method
-        MyAnnotatedController<String> annotatedTextController = new MyAnnotatedController<>();
-        annotatedTextController.doSomething();
+  public static void main(String[] args) {
+    // Use class type directly so as to call its method
+    MyAnnotatedController<String> annotatedTextController = new MyAnnotatedController<>();
+    annotatedTextController.doSomething();
 
-        // Print all declared methods (should also show interface methods introduced via ITD)
-        for (Method method : annotatedTextController.getClass().getDeclaredMethods()) {
-            if (!method.getName().startsWith("ajc$"))
-                System.out.println(method);
-        }
+    // Print all declared methods (should also show interface methods introduced via ITD)
+    for (Method method : annotatedTextController.getClass().getDeclaredMethods()) {
+      if (!method.getName().startsWith("ajc$"))
+        System.out.println(method);
+    }
 
-        // Prove that class type is compatible with interface type
-        //IEntityController<String> entityTextController = annotatedTextController;
-        //entityTextController.setEntity("foo");
-        // Would not work here because generic interface type is type-safe:
-        // entityNumberController.setEntity(123);
-        //System.out.println("Entity value = " + entityTextController.getEntity());
+    // Prove that class type is compatible with interface type
+    //
+    // NOTE: As explained in https://bugs.eclipse.org/bugs/show_bug.cgi?id=442425#c2, @DeclareParents will add the
+    // raw form of the parent to the target class, not the generic one. Therefore, the additional cast is necessary.
+    // Otherwise, AJC would throw:
+    //   Type mismatch: cannot convert from MyAnnotatedController<String> to IEntityController<String>
+    IEntityController<String> entityTextController = (IEntityController<String>) annotatedTextController;
+    entityTextController.setEntity("foo");
+    // Would not work here because generic interface type is type-safe:
+    // entityNumberController.setEntity(123);
+    System.out.println("Entity value = " + entityTextController.getEntity());
 
-        // Create another object and directly assign it to interface type
-        //IEntityController<Integer> entityNumberController = new MyAnnotatedController<>();
-        //entityNumberController.setEntity(123);
-        // Would not work here because generic interface type is type-safe:
-        // entityNumberController.setEntity("foo");
-        //System.out.println("Entity value = " + entityNumberController.getEntity());
-    }
+    // Create another object and directly assign it to interface type.
+    //
+    // NOTE: As explained in https://bugs.eclipse.org/bugs/show_bug.cgi?id=442425#c2, @DeclareParents will add the
+    // raw form of the parent to the target class, not the generic one. Therefore, the additional cast is necessary.
+    // Otherwise, AJC would throw:
+    //   Cannot infer type arguments for MyAnnotatedController<>
+    IEntityController<Integer> entityNumberController = (IEntityController<Integer>) new MyAnnotatedController<>();
+    entityNumberController.setEntity(123);
+    // Would not work here because generic interface type is type-safe:
+    // entityNumberController.setEntity("foo");
+    System.out.println("Entity value = " + entityNumberController.getEntity());
+  }
 }
-