Update test

Make sure to print when a control character is present. If it doesn't,
it leads to confusion when bash reports two apparently-equal strings
don't actually match due to the presence of a non-printing character.

t/funcs.sh

@@ -4,25 +4,29 @@
 echo_success() {
     printf '[\033[1;32m%s\033[0;39m] %s' \
         '  OK  ' \
-        "$*"
+        "$(escape_nonprinting "$*")"
 }
 
 echo_failure() {
     printf '[\033[1;31m%s\033[0;39m] %s' \
         'FAILED' \
-        "$*"
+        "$(escape_nonprinting "$*")"
 }
 
 echo_warning() {
     printf '[\033[1;33m%s\033[0;39m] %s' \
         'WARNING' \
-        "$*"
+        "$(escape_nonprinting "$*")"
 }
 
 echo_passed() {
     printf '[\033[1;33m%s\033[0;39m] %s' \
         'PASSED' \
-        "$*"
+        "$(escape_nonprinting "$*")"
+}
+
+escape_nonprinting() {
+    echo "$*" |cat -v
 }
 
 assert_equals() {