I am a sole developer working for an organisation that has no testing strategy.I am trying to integrate a crime system developed by a vendor with an external application I developed.  The external application allows an end user to send an instruction to the crime system to delete the crime.The crime system was developed by an external organisation and they have written stored procedures to actually execute the deletion, which I can call from my application.The crime system is complex i.e. it has a custody element, a crime element, an intelligence element etc. Whenever there is an upgrade to the crime system the stored procedures have to be retested and there are always many issues.  My approach is as follows:Test custodyReport custody issue 1New release by vendorReport custody issue nNew release by vendor.  All tests pass.Test crimeReport crime issue nNew release by vendor. All tests pass.Report intelligence issue nNew release by vendor.  All tests pass.Testing complete.  Goes live.The vendor has asked me to do all testing at once in future.  In my experience this does not work very well with this vendor because new issues are often introduced, which affect testing to do in future i.e. a custody change affects the crime element/intelligence element.Should I be testing everything and then submitting all of my findings?
Report test failures all at once, or report them one by one
testing