Add test fixture for Greeter type hierarchy and type trait registration

Author: captain-yoshi

Diff for: tests/include/greeter_test.h

@@ -0,0 +1,195 @@
+#ifndef GREETER_TEST_H_
+#define GREETER_TEST_H_
+
+#include <behaviortree_cpp/utils/safe_any.hpp>
+
+/**
+ *    +-------------------+------------+-------------+-----------------------------+
+ *    |       Class       | Base Class | Polymorphic | Type Trait Registered       |
+ *    +-------------------+------------+-------------+-----------------------------+
+ *    | Greeter           | -          | Yes         | Greeter                     |
+ *    | HelloGreeter      | Greeter    | Yes         | Greeter                     |
+ *    | FancyHelloGreeter | Greeter    | Yes         | Greeter                     |
+ *    | Unwelcomer        | -          | Yes         | Greeter (Purposely invalid) |
+ *    +-------------------+------------+-------------+-----------------------------+
+ */
+
+class Greeter
+{
+public:
+  using Ptr = std::shared_ptr<Greeter>;
+  virtual ~Greeter() = default;
+  virtual std::string show_msg() const
+  {
+    return "";
+  };
+};
+
+class HelloGreeter : public Greeter
+{
+public:
+  using Ptr = std::shared_ptr<HelloGreeter>;
+  std::string show_msg() const override
+  {
+    return "hello";
+  }
+  void setDerivedParameter(int n){};
+};
+
+class FancyHelloGreeter : public HelloGreeter
+{
+public:
+  using Ptr = std::shared_ptr<FancyHelloGreeter>;
+  std::string show_msg() const override
+  {
+    return "salutations";
+  }
+};
+
+class Unwelcomer
+{
+public:
+  using Ptr = std::shared_ptr<Unwelcomer>;
+  virtual ~Unwelcomer() = default;
+  virtual std::string show_msg() const
+  {
+    return "You’re not welcome here";
+  };
+};
+
+// Register cast base type for self to allow direct cast
+template <>
+struct BT::any_cast_base<Greeter>
+{
+  using type = Greeter;
+};
+
+// Register cast base type for HelloGreeter
+template <>
+struct BT::any_cast_base<HelloGreeter>
+{
+  using type = Greeter;
+};
+
+// Register cast base type for FancyHelloGreeter
+template <>
+struct BT::any_cast_base<FancyHelloGreeter>
+{
+  using type = Greeter;
+};
+
+// Register cast base type for Unwelcomer
+// WARNING: intentionally incorrect
+template <>
+struct BT::any_cast_base<Unwelcomer>
+{
+  using type = Greeter;
+};
+
+/**
+*    +-------------------+--------------+-------------+-----------------------+
+*    |     Class         | Base Class   | Polymorphic | Type Trait Registered |
+*    +-------------------+--------------+-------------+-----------------------+
+*    | GreeterNoReg      | -            | Yes         | -                     |
+*    | HelloGreeterNoReg | GreeterNoReg | Yes         | -                     |
+*    +-------------------+--------------+-------------+-----------------------+
+*/
+
+class GreeterNoReg
+{
+public:
+  using Ptr = std::shared_ptr<GreeterNoReg>;
+  virtual ~GreeterNoReg() = default;
+  virtual std::string show_msg() const
+  {
+    return "";
+  };
+};
+
+class HelloGreeterNoReg : public GreeterNoReg
+{
+public:
+  using Ptr = std::shared_ptr<HelloGreeterNoReg>;
+  std::string show_msg() const override
+  {
+    return "hello";
+  }
+  void setDerivedParameter(int n){};
+};
+
+/**
+*    +--------------------+---------------+-------------+-----------------------+
+*    |     Class          | Base Class    | Polymorphic | Type Trait Registered |
+*    +--------------------+---------------+-------------+-----------------------+
+*    | GreeterNoPoly      | -             | No          | GreeterNoPoly         |
+*    | HelloGreeterNoPoly | GreeterNoPoly | No          | GreeterNoPoly         |
+*    +-----------------------+------------+-------------+-----------------------+
+*/
+
+// Correctly fails to compile:
+//     static_assert(std::is_polymorphic_v<Base>, "Base must be polymorphic");
+
+// class GreeterNoPoly
+// {
+// public:
+//   using Ptr = std::shared_ptr<GreeterNoPoly>;
+//   std::string greet() const
+//   {
+//     return "";
+//   };
+// };
+//
+// class HelloGreeterNoPoly : public GreeterNoPoly
+// {
+// public:
+//   using Ptr = std::shared_ptr<HelloGreeterNoPoly>;
+//   std::string hello_greet()
+//   {
+//     return "hello" + greet();
+//   }
+// };
+//
+// // Register cast base type for self to allow direct cast
+// template <>
+// struct BT::any_cast_base<GreeterNoPoly>
+// {
+//   using type = GreeterNoPoly;
+// };
+//
+// // Register cast base type for HelloGreeter
+// template <>
+// struct BT::any_cast_base<HelloGreeterNoPoly>
+// {
+//   using type = GreeterNoPoly;
+// };
+
+/**
+*    +-----------------------+------------+-------------+-----------------------+
+*    |     Class             | Base Class | Polymorphic | Type Trait Registered |
+*    +-----------------------+------------+-------------+-----------------------+
+*    | GreeterNoPolyReg      | -          | No          | -                     |
+*    | HelloGreeterNoPolyReg | NoGreeter  | No          | -                     |
+*    +-----------------------+------------+-------------+-----------------------+
+*/
+
+class GreeterNoPolyReg
+{
+public:
+  using Ptr = std::shared_ptr<GreeterNoPolyReg>;
+  std::string greet() const
+  {
+    return "";
+  };
+};
+
+class HelloGreeterNoPolyReg : public GreeterNoPolyReg
+{
+public:
+  using Ptr = std::shared_ptr<HelloGreeterNoPolyReg>;
+  std::string hello_greet()
+  {
+    return "hello" + greet();
+  }
+};
+
+#endif  // GREETER_TEST_H_