Converting a JSON object into a response object

Question

I am trying to pass mock JSON data into my jasmine unit test.

The format of my JSON is like the one below:

{   
   "CompanyResponse":{    
      "CompanyCreatedDate":"1990-10-02",    
      "RunDate":"2",   
      "LastChangedDate":"2015-10-02",   
      "CompanySummary": {   
         "Id":"Apple",   
         "MaximumCredit":"10000000",   
         "Margin":"60000000",    
         "Limit":"-1500000",    
         "HistoricData":{    
            "CompanyHistoricData": [   
               {  
                  "LaunchDate":"2008-08-31",  
                  "Product":"Iphone2",  
                  "TotalProductsCreated":"1000000",  
                  "TotalProductsSold":"800000",  
                  "TotalReturns":"200000",  
                  "TotalMargin":"600000"  
               },  
               {  
                  "LaunchDate":"2010-08-31",  
                  "Product":"Iphone4",  
                  "TotalProductsCreated":"2000000",  
                  "TotalProductsSold":"1500000",  
                  "TotalReturns":"350000",  
                  "TotalMargin":"800000"  
               }  
            ]  
         },  
         "RefurbishedData": {  
            "CompanyRefurbished": [  
               {  
                  "Id":"Apple.201221.12",  
                  "ProductId":"iph-213454",  
                  "StartDate":"2015-09-07",  
                  "FinishDate":"2015-09-10",  
                  "CostOfRefurbishing":"50"  
               },  
               {  
                  "Id":"Apple.201228.12",  
                  "ProductId":"iph-4155655",  
                  "StartDate":"2015-09-10",    
                  "FinishDate":"2015-09-12",  
                  "CostOfRefurbishing":"85"  
               }  
            ]  
         }  
      }  
   }  
}  

I am using the above JSON to pass on to a function similar to the one below for unit testing:

public getTotal(response: CompanyResponse): void {    
  var companySummary = response.CompanySummary;    
  
  //gets total 'CostOfRefurbishing' for all phones    
  var totalRefurbishmentAmount :number = 0;

  for (let companyRefurbishments of companySummary.RefurbishedData) {
    totalRefurbishmentAmount += Number.parseInt(companyRefurbishments.CostOfRefurbishing.toString());
  }
}

---

The problem I am facing is that I am not able to pass CompanyResponse as a whole to the getTotal() function. It doesn't work even if I use JSON.stringify() because it just converts it to a string and it doesn't work if I use JSON.parse() either as it converts it back into the Object format.

Here's how we call the getTotal() method in a normal scenario:

export class MyService{    
 async CompanySummary(): Promise<CompanySummaryResponse>    
{    
    const response = await this.http.fetch('CompanySummary');    
    return await response.json();    
  }    
}    

var myService = new MyService();    
CompanySummary: CompanySummaryResponse;    
CompanySummary = await myService.CompanySummary();    
this.calculator.getTotal(CompanySummary);    

Cheers, Guru

Eusebioeusebius

Where is Reallocations in your data? – Hydrosphere

You need CompanyResponse to have a constructor that takes that object, or something derived from that object, as parameter – Pestana

@torazaburo sorry my bad. its RefurbishedData in the JSON, not Reallocations – Eusebioeusebius

@Pestana , this is a part of unit testing and I am trying not to restructure my program in order to make the unit test work. In the real scenario its an HTTP call that gives me the real response JSON. – Eusebioeusebius

Answer 1

Can you use the standard Response Interface from the JavaScript Fetch API to mock a response object?

If you look at the documentation for the constructor method - it accepts a body parameter and an init options object. The body parameter can be a Blob, so you could;

var data = {foo: "bar"};
var blob = new Blob([JSON.stringify(data, null, 2)], {type : 'application/json'});

var init = { "status" : 200 , "statusText" : "SuperSmashingGreat!" };
var myResponse = new Response(blob, init);

This would create a Response object that you should be able to pass to your test.

Holsworth

Tried the above approach, the issue is still the same. The getTotal function complains about not being able to accept the parameter of type "Response" – Eusebioeusebius

@GuruduttShenoy When you use getTotal normally - what is passed to it? – Holsworth

Have added a normal call to the getTotal() along with the service call through which it gets the JSON data in the last part of my question posted above. stackoverflow.com/users/297243/thebluefox – Eusebioeusebius

. the issue is resolved now. the issue was actually with passing of the parent element 'CompanyResponse' as a part of the JSON file. Returns the expected Response with the standard response interface from FetchApi you mentioned earlier. Thanks a lot for your help :) stackoverflow.com/users/297243/thebluefox – Eusebioeusebius

My pleasure @GuruduttShenoy - glad you got it sorted! – Holsworth