I just want to ask if is it possible to create a complex csv file inside a Testdrive in creating a Pester test for a function? Complex in a sense that it has 13 headers and no null values?
You can create any kind of file inside testdrive:\ (which are just like any kind of PSDrive) although it is of course only available temporarily within the context or describe block that it is used.
TestDrive is a PowerShell PSDrive for file activity limited to the scope of a single Describe or Context block.