Error in generated js by typescript compiler

[pooyaho]

I have a problem with type script generated js file and I can't solve it, this is my service file that I have problem with it:

namespace Providers {

    export interface IProvider {
        loadTranslations(translations: ITranslations, locale: string);
    }
    module.provider('lego', LegoProvider); 

    class LegoProvider implements ng.IServiceProvider ,IProvider{

        loadTranslations(translations:ITranslations , locale: string) {
            ......
        }

        $get() {
            .....
        }
    }

}

and generated js file is:

var Providers;
(function (Providers) {
    module.provider('lego', LegoProvider); // this is the problem
var LegoProvider = (function () {
    function LegoProvider() {
}
LegoProvider.prototype.loadTranslations = function (translations, locale) {
};
LegoProvider.prototype.$get = function () {
};
return LegoProvider;
}());
})(Providers || (Providers = {}));

It throws error because of the LegoProvider is variable and in that line it is still undefined. when I change code with this, it works correctly:

namespace Providers {

    export interface IProvider {
        loadTranslations(translations: ITranslations, locale: string);
    }


    class LegoProvider implements ng.IServiceProvider ,IProvider{

        loadTranslations(translations:ITranslations , locale: string) {
            ......
        }

        $get() {
            .....
        }
    }
    module.provider('lego', LegoProvider); // I've moved this line to bottom

}

In typescript code LegoProvider class is accessible from both positions and it doesn't make sense for me that the first position is incorrect

[RyanCavanaugh]

Code runs in the order you write it; TypeScript doesn't re-order it on your behalf. It's possible you needed to run module.provider before class initialization (for example, because LegoProvider initialized a static field in a way that depended on the module.provider call).

[normalser]

@RyanCavanaugh is there any way that TS could throw an error in such cases - kind of like when you try to use variable that is declared later in the file - got bitten by it myself couple of times

[basarat]

@wallverb you are always going to run into errors if you depend on ordering across files : https://basarat.gitbooks.io/typescript/content/docs/tips/outFile.html

However in this case I think TS should error similar to how it does for other block items:

console.log(foo); // Block scoped variable used before its declaration
let foo;

This is because ES6 classes are block scoped and not hoisted (similar to let/const) 🌹

[DanielRosenwasser]

There's #5207.