assert.eq( 17 , db.eval( function(){ return 11 + 6; } ) , "A" );
assert.eq( 17 , db.eval( function( x ){ return 10 + x; } , 7 ) , "B" );

// check that functions in system.js work
db.system.js.insert({_id: "add", value: function(x,y){ return x + y;}});
assert.eq( 20 , db.eval( "this.add(15, 5);" ) , "C" );