Modified test EXAMPLE_1 to fail if can't receive proper print from Mbed

libraries/tests/mbed/dev_null/main.cpp

@@ -19,9 +19,9 @@ DevNull null("null");
 
 int main()
 {
-    printf("MBED: re-routing stdout to /null\n");
+    printf("MBED: re-routing stdout to /null\r\n");
     freopen("/null", "w", stdout);
-    printf("MBED: printf redirected to /null\n");   // This shouldn't appear
+    printf("MBED: printf redirected to /null\r\n");   // This shouldn't appear
     // If failure message can be seen test should fail :)
     notify_completion(false);   // This is 'false' on purpose
     return 0;

workspace_tools/host_tests/dev_null_auto.py

@@ -20,13 +20,22 @@ from sys import stdout
 
 class DevNullTest(DefaultTest):
     def run(self):
-        c = self.mbed.serial_read(512)
+        c = self.mbed.serial_read(128)
         if c is None:
             self.print_result("ioerr_serial")
             return
         # Data from serial received correctly
-        print "Received %d bytes" % len(c)
+        print "Received %d bytes:"% len(c)
-        if "{failure}" not in c:
+        print c
+        # Check for expected and unexpected prints in Mbed output
+        result = True
+        if "re-routing stdout to /null" not in c:
+            result = False
+        if "printf redirected to /null" in c:
+            result = False
+        if "{failure}" in c:
+            result = False
+        if result:
             self.print_result('success')
         else:
             self.print_result('failure')