ROT13 Javascript BDD example with Jasmine

rot13.js

function rot13( text )
{
	var results = [];
	var charcode;
	for ( var i = 0; i < text.length; ++i )
	{
		charcode = text.charCodeAt( i );

		if ( charcode < 65 || charcode > 90 )
		{
			throw new Error( 'Gooby pls' );
		}

		charcode = 65 + ( charcode + 13 - 65 ) % 26; 

		results.push( String.fromCharCode( charcode ) );
	}

	return results.join('');
}

test_rot13.js

describe("ROT13 encoding", function() 
{

	it( "should encode normal text", function() 
	{
		expect( rot13( "TEST" ) ).toEqual( "GRFG" );
	} );

	it( "should fail for special characters", function() 
	{
		expect( function() 
		{
			return rot13( "$*=" );	
		} ).toThrow();
	});

});