This should now be fixed, Summer '20 patch 7 is live on almost all Summer 20 sandbox pods as of this edit
This was caused by an attempt to fix a different callout testing related bug in Summer '20 (specifically, this one: https://success.salesforce.com/issues_view?id=a1p3A000000ATF1QAO) that clearly didn't work as we had intended. That fix is being rolled ...
You need to do this in a single test. Data processed by one test method is not available to another. Each method has its separate transaction.
Insert the test records.
Schedule the job, after the startest().
Query the result and assert after the stopTest().
You need to query the PersonContactId field and use that instead. 001 is always an Account Id, while 003 is always a Contact Id.
Should be more like:
return [SELECT FirstName, LastName, PersonContactId, PersonEmail FROM Account WHERE Id = :accountList];
Then you can:
Instead of using return value, you can directly use the RestContext response.
As per the documentation here below is true for responseBody property of RestResponse class
The response is either the serialized form of the method return value or it's the value of the responseBody property based on the following rules:
If the method returns void, then Apex ...