Assertion Demonstration

Test of Code for SitePoint Article

Evaluating

	assert(false);
	assert(true);
	assert('false');

Waring: Assertion failed in example code on line 1.
Waring: Assertion false failed in example code on line 3.

Evaluating

	$one = 1;
	$three = 3;
	assert("$one + $one == $three");
	assert('$one + $one == $three');

Waring: Assertion 1 + 1 == 3 failed in example code on line 3.
Waring: Assertion $one + $one == $three failed in example code on line 4.

Evaluating

	define('MAX_CACHE_AGE', 60 * 60 * 24);
	$timestamp = time() - 2 * 60 * 60 * 24;	// make it 2 days old
	assert('time() - $timestamp <= MAX_CACHE_AGE');

Waring: Assertion time() - $timestamp <= MAX_CACHE_AGE failed in example code on line 3.

Evaluating

	define('XL', 'Extra Large');
	class clothes {
	    var $size;
	    function clothes($s) {
		$this->size = $s;
	    }
	    function size() {
		return $this->size;
	    }
	};
	$socks = new clothes(XL);
	assert('$socks->size() != XL');

Waring: Assertion $socks->size() != XL failed in example code on line 12.

Evaluating

	function customer_exists($dummy) {
	    return false;
	}
	class shopping_cart {
	    function get_customer_id() {
		return 1;
	    }
	};
	$cart = new shopping_cart;
	assert('customer_exists($cart->get_customer_id())');

Waring: Assertion customer_exists($cart->get_customer_id()) failed in example code on line 10.

Evaluating

	$some_variable = '1';
	switch ($some_variable) {
		case 'a':
			//...
	 		break;
		case 'b':
			//...
			break;
		//...
		default:
			assert('$some_variable != ' . "$some_variable");
			break;
	}

Waring: Assertion $some_variable != 1 failed in example code on line 11.

Evaluating

	$fp = NULL;
	assert('is_resource($fp)');

Waring: Assertion is_resource($fp) failed in example code on line 2.

Evaluating

	function some_function($positive_int_parameter) {
		assert('isset($positive_int_parameter)');
		assert('is_int($positive_int_parameter)');
		assert('$positive_int_parameter > 0');
		//...
	}
	some_function($foo);
	some_function('Hello');
	some_function(-22);

Waring: Assertion isset($positive_int_parameter) failed in example code on line 2.
Waring: Assertion is_int($positive_int_parameter) failed in example code on line 3.
Waring: Assertion $positive_int_parameter > 0 failed in example code on line 4.
Waring: Assertion is_int($positive_int_parameter) failed in example code on line 3.
Waring: Assertion $positive_int_parameter > 0 failed in example code on line 4.
Waring: Assertion $positive_int_parameter > 0 failed in example code on line 4.

Evaluating

	define('MAX_RESULT_LEN',10);
	function process_string($dummy) {
	    return 'Here is a string longer than the max.';
	}
	$result = process_string($input_string);
	assert('strlen($result) <= MAX_RESULT_LEN');

Waring: Assertion strlen($result) <= MAX_RESULT_LEN failed in example code on line 6.

Evaluating

	function expensive_crunching_routine($i) {
		return 1;
	}
	function alternate_expensive_crunching_routine($i) {
		return 2;
	}
	$input = 0;
	$output = expensive_crunching_routine($input);
	assert('$output == alternate_expensive_crunching_routine($input)');

Waring: Assertion $output == alternate_expensive_crunching_routine($input) failed in example code on line 9.

Evaluating

	$year_data = '1,2,1,2,0,0,2,0,0,2,0,0,2,2,2';
	define('MIN_FIRST_MONTH',10);
	assert(list($january, $ignore) = explode(',',$year_data));
	assert('$january > MIN_FIRST_MONTH');

Waring: Assertion $january > MIN_FIRST_MONTH failed in example code on line 4.