Use PHP functions in JavaScript

JavaScript assert

Checks if assertion is false

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function assert (assertion) {
    // Checks if assertion is false  
    // 
    // version: 1008.1718
    // discuss at: http://phpjs.org/functions/assert    // +   original by: Brett Zamir (http://brett-zamir.me)
    // %          note 1: Do not pass untrusted user input to assert() in string form (you can test it beforehand though)
    // %          note 2: Does not provide perfect arguments to the assertion callback, as far as file location or line number
    // *     example 1: assert('false === true');
    // *     returns 1: false 
    var result = false, callback, retVal, err=undefined;
 
    // BEGIN REDUNDANT
    this.php_js = this.php_js || {};    this.php_js.ini = this.php_js.ini || {};
    this.php_js.assert_values = this.php_js.assert_values || {};
    // END REDUNDANT
 
    var getOption = function (value) {        if (this.php_js.assert_values[value]) {
            return this.php_js.assert_values[value];
        }
        if (this.php_js.ini[value]) {
            return this.php_js.ini[value].local_value;        }
        switch (value) {
            case 'assert.active':
                return 1;
            case 'assert.warning': // Don't need this now                //return 1;
                throw 'We have not yet implemented warnings in JavaScript (assert())';
            case 'assert.bail':
                return 0;
            case 'assert.quiet_eval':                return 0;
            case 'assert.callback':
                return null;
            default:
                throw 'There was some problem';        }
    };
 
    if (!getOption('assert.active')) {
        return false; // is this correct? should callbacks still execute? Should still bail if on?    }
 
    try { // Less overhead to use string when assertion checking is off, allows message of exact code to callback
        result = typeof assertion === 'string' ? eval(assertion) : assertion;
    }    catch (e) {
        if (!getOption('assert.quiet_eval')) {
            throw e;
        }
        err = e;        result = false;
    }
    retVal = result !== false; // return false if false, otherwise, return true
    if (retVal === false) {
        if (getOption('assert.bail')) { // Todo: Will the function bail before a callback or after?            throw 'Assertion bailed'; // No way to bail without throwing an exception (and there are no "warnings" in JavaScript for us to throw)
        }
        callback = getOption('assert.callback');
        if (typeof callback === 'string') {
            callback = this.window[callback];        }
        // Not perfect for file location (might also use __FILE__()) or line number
        callback(this.window.location.href, err && err.lineNumber, (typeof assertion === 'string' ? assertion : '')); // From the docs, what does this mean?: "the third argument will contain the expression that failed (if any - literal values such as 1 or "two" will not be passed via this argument)"
    }
    return retVal;}
external links: original PHP docs | raw js source

Examples

Running

1
assert('false === true');

Should return

1
false

Dependencies

No dependencies, you can use this function standalone.

Open syntax issues

php.js uses JsLint to help us keep our code consistent and prevent some common bugs.

Eventually we want all code to pass or at least take into consideration most fixes suggested by JsLint, following this JsLint configuration we’ve decided on.


Authors

Thanks to the following developers, you get to have assert goodness in JavaScript.

Comments

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Use:
[CODE]
your_stuff('here');
[/CODE]
for proper code formatting
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More functions

In this category

» assert
assert_options
get_cfg_var
get_defined_constants
get_extension_funcs
get_include_path
get_included_files
get_required_files
getenv
getlastmod
ini_alter
ini_get
ini_get_all
ini_restore
ini_set
php_ini_loaded_file
php_ini_scanned_files
phpversion
putenv
restore_include_path
set_include_path
set_time_limit
version_compare

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