Docs | Testing vs Validation

Testing and Validation

This is a Venn Diagram situation.

Validation is focused on the Current State (of the Workbook) and its Data
Validation error could typically be fixed by a business end user (which is not the case with Unit Tests)
Addin-defined Validation runs by default on new host workbook (unit tests do not)*
Validation should not risk corrupting existing workbook data (whereas Unit Tests can)
Validation should not make network connection (whereas Tests can)
Validation is far less useful with an unloaded Host Workbook (eg no imported Data)
Validation - also meant to be like "Tuning & Alignment" ... We expect users to run validation

Tests are focused on checking the VBA project code.
Test errors would be typically be fixed by a vba coder, not a business end user
Tests lean more towards infrastructure (whereas Validation leans towards business/data)
Tests can risk data, because end users do not run them
Tests can run a little slower

Deployment checks are the last thing you do before releasing a new version of your application.
Deployment automatically runs all defined Unit Test and Validation procedures...
And then checks anything other special conditions you want to verify before releasing a version.
Anytime you release a version and (later) notice you "forgot" to do something; that "something" is likely a good candidate to include in pre-deployment checks.
Ideas for deployment checks:
Are any inputs or data ranges that should be clear, not cleared?
Are any DB Models populated with records, which should be zeroed out?
Are there any "generated worksheets" (created by your code) that should be deleted?

Reset scripts are designed to "zero out" a host workbook to it's "empty" or "initial" state
If you were building an appraisal workbook, the reset script would clear out any imported rent comparables, sales comps, operating expense comps, etc.
In practice, your end users do not often run Reset scripts (because the base template they grab off the T-Drive was already reset).
Resets can also be used to normalize zoom, re-order worksheets, etc.