Call JavaScript function from UIViewController class in iOS

I want to call javascript function from one of my view controller class,

here is my code snippet i have tried, but it is not working :(

Code in my ViewController

- (NSString *)MyMehtod{
    JSContext *context = [[JSContext alloc] init];
    JSValue *function = context[@"ProfilePicFunction"];
  [context evaluateScript: [self loadJsFromFile]]; //crashes here EXC_BAD_ACESS
     JSValue* result = [function callWithArguments:@[[documentsDirectory stringByAppendingString:@"/ProfilePic.png"]]];
    NSLog(@"res = %@",result);
}

- (NSString *)loadJsFromFile
    {
        NSString *path = [[NSBundle mainBundle] pathForResource:@"app" ofType:@"js"]; //path returns here as nil
        NSString *jsScript = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil]; //jsScript returns here as nil
        return jsScript;
    }

Code in app.js file

function ProfilePicFunction(ProfilePicPath){
     var d= new Date();

    var userFullPath = ProfilePicPath+"?"+d.getTime();

    $("#userImg").attr("src",userFullPath);
}

Location of app.js Please help and thanks in advance!!