Merge branch '22.0-convenient-macros-for-ut' into 'master'

22.0 add convenient macro for unit testing

See merge request !1016

AtlasTest/TestTools/TestTools/expect.h

+/*
+Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+*/
+
+#ifndef TestTools_expect_h
+#define TestTools_expect_h
+
+#undef NDEBUG
+#include <cassert>
+
+namespace Athena_test {
+
+  /*
+   * Helpers for float/double comarisons with the precision and every other type exactly
+   */
+  template <typename T>
+  bool cmp_eq( T a, T b ) {  return a == b; }
+  template<>
+  bool cmp_eq<float>( float a, float b ) { return std::abs(a - b) < 1.e-4; }
+  template<>
+  bool cmp_eq<double>( double a, double b ) { return std::abs(a - b) < 1.e-6; }
+
+  /*
+   * Helper class, offering method to compare for equality to the value captured during construction.
+   * In case of a difference the message of what is the value captured and what was expected 
+   * is printed. In addition the assertion macro is used to make the test failing in this case.
+   *  
+   * There is also a symmetric method for checking for inequality.
+   */
+  template <typename T>
+  class TestedValue {
+  public:
+    TestedValue( T v, std::string&& f, int l)
+      : m_value(v),
+	m_file(std::move(f)),
+	m_line(l) {}
+    void EXPECTED( const T& e ) {
+      if ( not cmp_eq(e, m_value) ) {
+	std::cerr << m_file << ":" << m_line << ": error: Test failed, " 
+		  << "expected: " << e << " obtained: " << m_value << "\n";
+	assert( cmp_eq(e, m_value) );
+      }
+    }
+    void NOT_EXPECTED( const T& e ) {
+      if ( cmp_eq(e, m_value) ) {
+	std::cerr << m_file << ":" << m_line << ": error: Test failed, " 
+		  << "NOT expected: " << e << " obtained: " << m_value << "\n";
+	assert( not cmp_eq(e, m_value) );
+      }
+    }
+  private:
+    T m_value;
+    std::string m_file;
+    int m_line;
+  };
+}
+
+#define VALUE( TESTED ) Athena_test::TestedValue<decltype(TESTED)>(TESTED, __FILE__, __LINE__).
+
+/*
+ * @brief macros (& simple class) for human readable stating assertions in unit tests
+ * The syntax will be:
+ * VALUE ( x ) EXPECTED ( true );  // exact comparisons
+ * VALUE ( y ) EXPECTED ( "something");
+ * VALUE ( z ) EXPECTED ( 3.1415 ); // this would compare with precision 1e-4 for floats and 1e-6 for doubles
+ * VALUE ( t ) NOT_EXPECTED ( 0 ); // the inverted check is also possible
+ */
+
+#endif // TestTools_expect_h