Added further optimizations and unit tests.

test/val/lib_common_strspn.c

@@ -0,0 +1,24 @@
+#include <string.h>
+#include "unittest.h"
+
+#define EstimatedStringSize 384                         // test correct page passing (>256)
+
+static char EstimatedString[EstimatedStringSize+1];     // +1 room for terminating null
+static char* EmptyTestChars="";                         // empty test case...
+static char* TestChars="1234567890";                    // we like to find numbers
+
+TEST
+{
+    unsigned i;
+    
+    for (i=0; i < EstimatedStringSize; ++i)
+      EstimatedString[i] = (i%10)+'0';                 // put 0123... into the string to be estimated
+
+    ASSERT_AreEqual(strlen(EstimatedString), strspn(EstimatedString, TestChars), "%u", "Unxpected position returned for all participant case!");
+
+    EstimatedString[EstimatedStringSize/2] = 'X';
+    ASSERT_AreEqual(EstimatedStringSize/2, strspn(EstimatedString, TestChars), "%u", "Unxpected position returned for breaking case!");
+
+    ASSERT_AreEqual(0, strspn(EstimatedString, EmptyTestChars), "%u", "Unxpected position returned for empty test case!");
+}
+ENDTEST