[Cppunit-devel] templatized assertions

[Steve M. R. <ste...@vi...>]

Hello,

Using 1.5.5, I can see two flavours of assertions:

	assert( boolean )
and	assertDoublesEqual( double, double ) [ also assertLongsEqual() ]

The second form is potentially very useful, since it allows the
diagnostic message to say "expected X, got Y".  I'd like to extend
this form of assertion to arbitrary types.  

To this end, I've added templatized assertEquals() and
notEqualsMessage() member functions to class TestAssert, and a new
assertion macro "assertEqual(x,y)".  The assertion will work on any
type that has operator=() and operator<<().

The patch below does work.  Before I go further down this road and
submit a full patch with doc changes, and the whole 9 yards, I thought
I'd check to see whether you folks see a problem with this approach.
Perhaps this approach has been previously considered and discarded?

Comments?
-Steve



Index: include/cppunit/TestAssert.h
===================================================================
RCS file: /cvsroot/cppunit/cppunit/include/cppunit/TestAssert.h,v
retrieving revision 1.2
diff -u -b -B -r1.2 TestAssert.h
--- include/cppunit/TestAssert.h	2001/05/06 16:19:31	1.2
+++ include/cppunit/TestAssert.h	2001/05/15 20:20:50
@@ -2,6 +2,7 @@
 #define CPPUNIT_TESTASSERT_H
 
 #include <string>
+#include <sstream>
 #include <cppunit/Exception.h>
 
 namespace CppUnit {
@@ -19,22 +20,34 @@
       long         lineNumber = Exception::UNKNOWNLINENUMBER,
       std::string  fileName = Exception::UNKNOWNFILENAME);
 
-    static void    assertEquals     (long         expected, 
-      long         actual,
+    template <class T>
+    static void    assertEquals     (
+      const T&     expected,
+      const T&     actual,
       long         lineNumber = Exception::UNKNOWNLINENUMBER,
-      std::string  fileName = Exception::UNKNOWNFILENAME);
+      std::string  fileName = Exception::UNKNOWNFILENAME)
+	{
+	    if (expected != actual)
+		assertImplementation (false, notEqualsMessage(expected, actual), lineNumber, fileName); 
 
+	}
+
     static void    assertEquals     (double       expected, 
       double       actual, 
       double       delta, 
       long         lineNumber = Exception::UNKNOWNLINENUMBER,
       std::string  fileName = Exception::UNKNOWNFILENAME);
 
-    static std::string         notEqualsMessage (long         expected, 
-      long         actual);
+    template <class T>
+    static std::string         notEqualsMessage (const T& expected, 
+						 const T& actual)
+	{
+	    ostringstream ost;
+	    ost << "expected: " << expected 
+		<< " but was: " << actual;
+	    return ost.str();
+	}
 
-    static std::string         notEqualsMessage (double       expected, 
-      double       actual);
   };
 
 
@@ -69,6 +82,15 @@
 
 /// Macro for primitive value comparisons
 #define assertLongsEqual(expected,actual)\
+(CppUnit::TestAssert::assertEquals ((expected),\
+        (actual),__LINE__,__FILE__))
+
+/// Generalized macro for primitive value comparisons
+/** Any type that implements operator= and operator<<
+ * can be compared.  A diagnostic is printed if the
+ * actual and expected values disagree.
+ */
+#define assertEqual(expected,actual)\
 (CppUnit::TestAssert::assertEquals ((expected),\
         (actual),__LINE__,__FILE__))
 



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