Node.js async parallel "TypeError: task is not a function"

Question

I am using the async module to execute parallel tasks. Basically, I have two different files, dashboard.js and Run.js.

Dashboard.js

module.exports = {

    func1 : function(){
        console.log(“Funtion one”);

    },
    func2 : function(){
        console.log(“Funtion two”);
    }

}

Run.js

    var dashboard = require(‘dashboard.js’);

    var async = require('async');

    async.parallel([dashboard.func1, dashboard.func2],function(err){
        if(err)throws err;
        console.log(“ All function executed”);
   });

I was expecting func1 and func2 to execute in parallel, but it is throwing the below error.

TypeError: task is not a function
    at C:\Users\..\java\realtime-preview\node_modules\async\lib\async.js:718:13
    at async.forEachOf.async.eachOf (C:\Users\..\java\realtime-preview\node_modules\async\lib\async.js:233:13)
    at _parallel (C:\Users\\java\realtime-preview\node_modules\async\lib\async.js:717:9)

why can I not use dashboard.func1, dashboard.func2 even if dashboard.func1 is a function?

These snippets don't seem likely to be exactly the code you're executing. You should be getting rather different errors. 1) Directional quotations aren't valid delimiters for string literals. You should be seeing SyntaxErrors for those. 2) To require() another file in your project, the path should be relative to the current file. require('dashboard.js') expects to find node_modules/dashboard.js. — Jonathan Lonowski
– Jonathan Lonowski, Commented Apr 17, 2016 at 17:37
try: adding bracket. For example. dashboard.func1() Hope this work — Michael Seltene
– Michael Seltene, Commented Apr 17, 2016 at 17:40
Good observation , I have posted sudo code not working code , assume require('./dashboard.js') @JonathanLonowski — Sumeet Kumar Yadav
– Sumeet Kumar Yadav, Commented Apr 17, 2016 at 17:41
dashboard.func1() does not work , it gives same error @MichaelSeltene — Sumeet Kumar Yadav
– Sumeet Kumar Yadav, Commented Apr 17, 2016 at 17:42
@Sumeet If wrapping the call in another function works, does your application have a cycle (circular reference)? If it does, to handle these, Node.js will only load one module up to the require() that starts the cycle. It will have to wait to finish loading it until after the other module(s) involved have loaded completely. — Jonathan Lonowski
– Jonathan Lonowski, Commented Apr 17, 2016 at 17:45

Peter Mortensen · Accepted Answer · 2020-10-13 23:31:33Z

2

For the async property, I would use the callback feature. This feature also benefits non-blocking calls.

With your code, you could try

File Dashboard.js

module.exports = {
   func1 : function(callback){
       var value = “Function one”;

       // If value happens to be empty, then undefined is called back
       callback(undefined|| value);
   },
   func2 : function(callback){
       var value = “Function two”;

       // If value happens to be empty, then undefined is calledback
       callback(undefined|| value);
   }
}

File Run.js

var dashboard = require(‘dashboard.js’);

   //func1
   dashboard.func1(function(callback){

     // If callback then do the following
     if(callback){
         console.log(callback);

     // If no data on callback then do the following
     }else{
         console.error('Error: ' + callback);
     }
   });

   //func2
   dashboard.func2(function(callback){

     // If callback then do the following
     if(callback){
         console.log(callback);

     // If no data on callback then do the following
     }else{
         console.error('Error: ' + callback);
     }
   });
});

There is also a question similar to yours: Best way to execute parallel processing in Node.js

In addition, a specific answer for the error is in: TypeError: task is not a function in async js parrallel

edited Oct 13, 2020 at 23:31

Peter Mortensen

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answered Apr 17, 2016 at 17:34

Michael Seltene

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1 Comment

Sumeet Kumar Yadav Over a year ago

why I am not able to add dashboard.func1 inside parallel

Sanjay Tiwari · Accepted Answer · 2023-10-08 10:25:43Z

0

Please make sure the API path you are using should not have any return .. I have resolve this issue after calling API like this ... Please not i was facing this while working in local


fetchLearnMoreProxy: (isoCode, langCode) =>
    `http://localhost:3001/api?url=${hostName}/api/abc/cde?country=${isoCode}&language=${langCode}`,

Please let me know if any question.

answered Oct 8, 2023 at 10:25

Sanjay Tiwari

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