Oh. My. Word. :sigh:

There's nothing like diagnosing and fixing your own equipment. Always gave me a sense of accomplishment, and a feeling of independence.

If I'm doing important managey work in Excel, I totally need a new AMD Threadripper with 128 GB of memory loaded with 10 TB of SSD drives. How else am I going to do Excelly type work, and write clever posts about important managey stuff on Linkedin.... ;) ;) ;)

The 16 GB of ram, then you add in all of the VPN, Malware, Anti-Virus, and monitoring bloatware that they need to secure the laptop and you have the modern day equivalent of a 486SX running on 640K of memory. Just my .02 :sigh:

When we are using Microsoft Test runner we use Moq to build out our mock data layer. We recently have been switching to xUnit, I haven't tried using Moq with it yet. Here is the link to the Moq GitHub repo, there's good info here.

In most of our web services I use the repository pattern. Isolating data access from business rules from controller/services. Here is a link to some docs on Microsoft. This isn't specific to Dotnet Core, but the same pattern can still be applied.

Why don't you use a sub-select for the date?

where (SaleDateFrom <= ( select max(your date column) from your table with date value ) and (SaleDateTo '20010101' or SaleDateTo is null ))

xUnit unit testing framework has the ability to use external data sources for unit testing. For example you could create a spreadsheet or a database table will a randomized set of data that can be used as the mocked source data for your unit testing. Here is a link to a blog post discussing it.