file IO: add sprintf tests

Author: fglock

src/main/java/org/perlonjava/runtime/GlobalContext.java

@@ -141,6 +141,10 @@ public static RuntimeScalar getGlobalVariable(String key) {
         return var;
     }
 
+    public static RuntimeScalar setGlobalVariable(String key, String value) {
+        return getGlobalVariable(key).set(value);
+    }
+
     public static boolean existsGlobalVariable(String key) {
         return globalVariables.containsKey(key);
     }

src/test/resources/operations.pl

@@ -154,12 +154,11 @@
 my $negative_width = sprintf("|%-10s|", "test");
 print "not " if $negative_width ne "|test      |"; say "ok # sprintf('|%-10s|', 'test') |$negative_width|";
 
-## XXX TODO
-## # Test invalid format string
-## my $invalid_format;
-## eval { $invalid_format = sprintf("%z", "data") };
-## print "not " if $@; # Expecting an error
-## print "ok # sprintf with invalid format string causes an error\n";
+# Test invalid format string
+my $invalid_format;
+eval { $invalid_format = sprintf("%z", "data") };
+print "not " if $@; # Expecting an error
+print "ok # sprintf with invalid format string causes an error\n";
 
 ###################
 # Logical Operators