Angular: module behavior, I don't understant javascript code if ("")

Question

I am using angularjs 1.4.3. And I have a curiosity because I don't understand a piece of code of the code generated by Jasmine Spec Runner.

When we generate it, Jasmine (via ChutzPath) create this code:

    (function () {
        var amdTestPaths = [];
        if (window.require && typeof window.require === "function" && amdTestPaths.length > 0) {
            if (window.chutzpah) {
                window.chutzpah.usingModuleLoader = true;
            }

            if("") {
                require.config({
                    baseUrl: ""
                });
            }

            require.config({
                map: {'*': { } }
            });

            window.require(amdTestPaths, function () {    
                console.log("!!_!! Stating Jasmine from AMD callback...");            
                window.initializeJasmine();
            });
        } else {
           var currentWindowOnload = window.onload;

           window.onload = function() {
           if (currentWindowOnload) {
               currentWindowOnload();
           }

           window.initializeJasmine();
       };
   }
})();

what is it if("")? I know that's stupid question but I don't ubderstand

maybe is like if (true) or if (1)?

`""` type coerces to false, so the code in the `if` statement will never be called. https://javascriptweblog.wordpress.com/2011/02/07/truth-equality-and-javascript/ — Oliver, Nov 30 '15 at 16:00
lol, people too complicated instead of set if (false) much better to understand, lol, but to large to write. — Dave, Nov 30 '15 at 16:11
given that the code is auto-generated, I assume that the `if` tests for more complex conditions in other cases. — Oliver, Nov 30 '15 at 16:14

score 2 · Accepted Answer · edited Jun 20 '20 at 09:12

As you know, the code within the if statement executes if its condition evaulates to the boolean true. If the condition does not return a boolean, javascript uses Type Coercion to interpret the condition as a boolean. You may read more about Type Coercion here:

What exactly is Type Coercion in Javascript?

An article giving the true/false values that different kinds of data takes when type coerced is available here:

https://javascriptweblog.wordpress.com/2011/02/07/truth-equality-and-javascript/

Quoting the relevant section in your case:

Conditionals

In JavaScript, all conditional statements and operators follow the same coercion paradigm. We’ll use the if statement by way of example.

The construct if ( Expression ) Statement will coerce the result of evaluating the Expression to a boolean using the abstract method ToBoolean for which the ES5 spec defines the following algorithm:
Argument Type   Result
Undefined       false
Null            false
Boolean         The result equals the input argument (no conversion).
Number          The result is false if the argument is +0, −0, or NaN;
                otherwise the result is true.
String          The result is false if the argument is the empty String 
                (its length is zero); otherwise the result is true.
Object          true.

Angular: module behavior, I don't understant javascript code if ("")

1 Answers1

Conditionals