How can I use one source file in node.js with javascript?

I have one code in node.js.

var testFunc = function( y, m, d ) {
        //- do something~~
        return chkDObj.getFullYear( ) == y && chkDObj.getMonth( ) == m && chkDObj.getDate( ) == d;
};

res.render( "index.jade", { testFunc: testFunc } );

In jade,

script 
    var tmp = #{testFunc}

I want it to show same thing, but render result is,

<script>
var tmp = function( u, m, d ) {
        //- do something~~
        return chkDObj.getFullYear( ) == y &amp;&amp; chkDObj.getMonth( ) == m &amp;&amp; chkDObj.getDate( ) == d;
        };
</script>

How can I manage one source file?

You can create js file like a utils.js, which is accessible through http and such as Node.js module. It's simple and works.

Jade escapes all data by default. You can disable escaping by changing jour jade template:

script 
    var tmp = !{testFunc}