How can I cover this contact owner assignment in test class after lead convert?

Question

I have written a trigger helper method that converts to contact and associates the contact with an existing account. The contact owner becomes the owner of the account as shown in this snippet

Now I dont know how to cover this assignment: c.OwnerId = c.Account.OwnerId;

I am getting the error :

Error occured while converting the Lead to a Contact in convertLeadToContact methodSObject row was retrieved via SOQL without querying the requested field: Contact.Account

Any ideas?

Thanks

// contains the list of created contacts after conversion
contList =  [select Id, OwnerId from Contact where Id IN :cidList]; 
            
//update contact owner with related account owner
if(cidList.size() > 0){
    for(Contact c : contList){
          c.OwnerId = c.Account.OwnerId;
    }
    update contList;
}

Answer 1

To answer the error question...

This is one of those cases where the error correctly tells you what the issue is.

...row was retrieved via SOQL without querying the requested field: Contact.Account

From Apex Developer Guide > Working with SOQL and SOSL Query Results https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/langCon_apex_SOQL_working_with_results.htm :

SOQL and SOSL queries only return data for sObject fields that are selected in the original query. If you try to access a field that was not selected in the SOQL or SOSL query (other than ID), you receive a runtime error, even if the field contains a value in the database.

To rectify:

1. Find where you have SOQL in your code snippet:

   contList =  [select Id, OwnerId from Contact where Id IN :cidList];
   

2. Find everywhere you reference fields using the variable which holds the results returned from your query:

   c.OwnerId
   c.Account.OwnerId
   

3. Compare the items in #2 to what you queried in #1:

   OwnerId
   

   Did I query for OwnerId? YES

   ...

   Account.OwnerId
   

   Did I query for Account.OwnerId? NO

4. Add Account.OwnerId to your query.