This adds some tests for `form.ts`, plus some minor changes to the validation for consistency, including:
- consider empty strings as "no answer" (eg. fail validation if required)
- treat empty inputs as "null" answer for optional fields
- validate individual parts of a list input
- use `null` for skipped answers of optional fields
POTENTIALLY BREAKING: For consistency, we always use `null` for skipped optional answers now. Previously an optional `list` field would get an empty array if skipped.

Merged

Closed