EXPECT_THROW_EQ and ASSERT_THROW_EQ macros for unittests

rclcpp/test/CMakeLists.txt

@@ -509,6 +509,11 @@ if(TARGET test_subscription_options)
   target_link_libraries(test_subscription_options ${PROJECT_NAME})
 endif()
 
+ament_add_gtest(test_gtest_macros utils/test_gtest_macros.cpp)
+if(TARGET test_gtest_macros)
+  target_link_libraries(test_gtest_macros ${PROJECT_NAME})
+endif()
+
 # Install test resources
 install(
   DIRECTORY resources

rclcpp/test/utils/gtest_macros.hpp

@@ -0,0 +1,195 @@
+// Copyright 2020 Open Source Robotics Foundation, 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.
+
+#ifndef UTILS__GTEST_MACROS_HPP_
+#define UTILS__GTEST_MACROS_HPP_
+
+#include "gtest/gtest.h"
+
+#include <cstring>
+#include <type_traits>
+
+#include "rclcpp/exceptions/exceptions.hpp"
+
+namespace rclcpp
+{
+namespace testing
+{
+namespace details
+{
+
+/**
+ * \brief Check if two thrown objects are equals.
+ *
+ * For generic thrown objects, probably is unlikely to be used. This type must
+ * overload the == and << operators.
+ */
+template<typename T,
+  typename = typename std::enable_if_t<
+    !std::is_convertible<T, std::exception>::value>>
+::testing::AssertionResult AreThrowableContentsEqual(
+  const T & expected, const T & actual, const char * expected_exception_expression,
+  const char * throwing_expression)
+{
+  if (expected == actual) {
+    return ::testing::AssertionSuccess() <<
+           "'\nThe value of the non-standard throwable thrown by the expression\n'" <<
+           throwing_expression << "'\n\nmatches the value of the expected thrown object\n'" <<
+           expected_exception_expression << "'\n\t(" << expected << " == " << actual << ")\n";
+  }
+
+  return ::testing::AssertionFailure() <<
+         "\nThe value of the non-standard throwable thrown by the expression\n'" <<
+         throwing_expression << "'\n\ndoes not match the value of the expected thrown object\n'" <<
+         expected_exception_expression << "'\n\t(" << expected << " != " << actual << ")\n";
+}
+
+/**
+ * \brief Check if two std::exceptions are equal according to their message.
+ *
+ * If the exception type also derives from rclcpp::Exception, then the next overload is called
+ * instead
+ */
+template<typename T,
+  typename = typename std::enable_if_t<
+    !std::is_convertible<T, rclcpp::exceptions::RCLErrorBase>::value>>
+::testing::AssertionResult AreThrowableContentsEqual(
+  const std::exception & expected, const std::exception & actual,
+  const char * expected_exception_expression,
+  const char * throwing_expression)
+{
+  if (std::strcmp(expected.what(), actual.what()) == 0) {
+    return ::testing::AssertionSuccess() <<
+           "'\nThe contents of the std::exception thrown by the expression\n'" <<
+           throwing_expression << "':\n\te.what(): '" << actual.what() <<
+           "'\n\nmatch the contents of the expected std::exception\n'" <<
+           expected_exception_expression << "'\n\te.what(): '" << expected.what() << "'\n";
+  }
+
+  return ::testing::AssertionFailure() <<
+         "\nThe contents of the std::exception thrown by the expression\n'" <<
+         throwing_expression << "':\n\te.what(): '" << actual.what() <<
+         "'\n\ndo not match the contents of the expected std::exception\n'" <<
+         expected_exception_expression << "'\n\te.what(): '" << expected.what() << "'\n";
+}
+
+/**
+ * \brief Check if two exceptions that derive from rclcpp::RCLErrorBase are equal.
+ *
+ * This checks equality based on their return and message. It does not check the formatted
+ * message, which is what is reported by std::exception::what() for RCLErrors.
+ */
+template<typename T,
+  typename = typename std::enable_if_t<
+    std::is_convertible<T, rclcpp::exceptions::RCLErrorBase>::value>>
+::testing::AssertionResult AreThrowableContentsEqual(
+  const rclcpp::exceptions::RCLErrorBase & expected,
+  const rclcpp::exceptions::RCLErrorBase & actual,
+  const char * expected_exception_expression,
+  const char * throwing_expression)
+{
+  if ((expected.ret == actual.ret) && (expected.message == actual.message)) {
+    return ::testing::AssertionSuccess() <<
+           "'\nThe contents of the RCLError thrown by the expression\n'" << throwing_expression <<
+           "':\n\trcl_ret_t: " << actual.ret << "\n\tmessage: '" << actual.message <<
+           "'\n\nmatch the contents of the expected RCLError\n'" <<
+           expected_exception_expression << "'\n\trcl_ret_t: " << expected.ret <<
+           "\n\tmessage: '" << expected.message << "'\n";
+  }
+
+  return ::testing::AssertionFailure() <<
+         "'\nThe contents of the RCLError thrown by the expression\n'" << throwing_expression <<
+         "':\n\trcl_ret_t: " << actual.ret << "\n\tmessage: '" << actual.message <<
+         "'\n\ndo not match the contents of the expected RCLError\n'" <<
+         expected_exception_expression << "'\n\trcl_ret_t: " << expected.ret << "\n\tmessage: '" <<
+         expected.message << "'\n";
+}
+
+}  // namespace details
+}  // namespace testing
+}  // namespace rclcpp
+
+/**
+ * \def CHECK_THROW_EQ_IMPL
+ * \brief Implemented check if statement throws expected exception. don't use directly, use
+ * EXPECT_THROW_EQ or ASSERT_THROW_EQ instead.
+ */
+#define CHECK_THROW_EQ_IMPL(throwing_statement, expected_exception, assertion_result) \
+  do { \
+    using ExceptionT = decltype(expected_exception); \
+    try { \
+      throwing_statement; \
+      assertion_result = ::testing::AssertionFailure() << \
+        "\nExpected the expression:\n\t'" #throwing_statement "'\nto throw: \n\t'" << \
+        #expected_exception "'\nbut it did not throw.\n"; \
+    } catch (const ExceptionT & e) { \
+      assertion_result = \
+        rclcpp::testing::details::AreThrowableContentsEqual<ExceptionT>( \
+        expected_exception, e, #expected_exception, #throwing_statement); \
+    } catch (const std::exception & e) { \
+      assertion_result = ::testing::AssertionFailure() << \
+        "\nExpected the expression:\n\t'" #throwing_statement "'\nto throw: \n\t'" << \
+        #expected_exception "'\nbut it threw:\n\tType: " << typeid(e).name() << \
+        "\n\te.what(): '" << e.what() << "'\n"; \
+    } catch (...) { \
+      assertion_result = ::testing::AssertionFailure() << \
+        "\nExpected the expression:\n\t'" #throwing_statement "'\nto throw: \n\t'" << \
+        #expected_exception "'\nbut it threw an unrecognized throwable type.\n"; \
+    } \
+  } while (0)
+
+/**
+ * \def EXPECT_THROW_EQ
+ * \brief Check if a statement throws the expected exception type and that the exceptions matches
+ *   the expected exception.
+ *
+ * Like other gtest EXPECT_ macros, this doesn't halt a test and return on failure. Instead it
+ * just adds a failure to the current test.
+ *
+ * See test_gtest_macros.cpp for examples
+ */
+#define EXPECT_THROW_EQ(throwing_statement, expected_exception) \
+  do { \
+    ::testing::AssertionResult \
+    is_the_result_of_the_throwing_expression_equal_to_the_expected_throwable = \
+      ::testing::AssertionSuccess(); \
+    CHECK_THROW_EQ_IMPL( \
+      throwing_statement, \
+      expected_exception, \
+      is_the_result_of_the_throwing_expression_equal_to_the_expected_throwable); \
+    EXPECT_TRUE(is_the_result_of_the_throwing_expression_equal_to_the_expected_throwable); \
+  } while (0)
+
+/**
+ * \def ASSERT_THROW_EQ
+ * \brief Assert that a statement throws the expected exception type and that the exceptions
+ * matches the expected exception.
+ *
+ * See test_gtest_macros.cpp for examples
+ *
+ * Like other gtest ASSERT_ macros, this will halt the test on failure and return.
+ */
+#define ASSERT_THROW_EQ(throwing_statement, expected_exception) \
+  do { \
+    ::testing::AssertionResult \
+    is_the_result_of_the_throwing_expression_equal_to_the_expected_throwable = \
+      ::testing::AssertionSuccess(); \
+    CHECK_THROW_EQ_IMPL( \
+      throwing_statement, \
+      expected_exception, \
+      is_the_result_of_the_throwing_expression_equal_to_the_expected_throwable); \
+    ASSERT_TRUE(is_the_result_of_the_throwing_expression_equal_to_the_expected_throwable); \
+  } while (0)
+
+#endif  // UTILS__GTEST_MACROS_HPP_