V7.0 dev feat/performance

[timcadman]

Description

• Remove checks exists and isDefined
• Written tests that correct error messages are returned

Checklist (not all may apply)

Refactor

• Remove exists and isDefined and add appropriate checks on server-side
• Remove code checking whether an object has been successfully created
• Review code to determine if additional refactoring could reduce calls to server-side package

Testing

• Writen client-side unit tests for unhappy flow
• Run and passed devtools::test(filter = "smk-|disc|arg")
• Run and passed devtools::check(args = '--no-tests') (we run tests separately to skip performance checks)
• Run and passed devtools::build

[StuartWheater]

I would try devtools::test(filter = "smk-|disc-|discctrl-|arg-") also adding "datachk-" if you wish to check test data sets.