Problem:
There are three different ways of marking an option as hidden, `enable_if
= false`, `hidden = true` and `immutable = true`. These also have different
behaviors. Options hidden with `enable_if = false` can't have their value
fetched using Vim script or the API, but options hidden with `hidden = true` or
`immutable = true` can. On the other hand, options with `hidden = true` do not
error when trying to set their value, but options with `immutable = true` do.
Solution:
Remove `enable_if = false`, remove the `hidden` property for options, and use
`immutable = true` to mark an option as hidden instead. Also make hidden option
variable pointers always point to the default value, which allows fetching the
value of every hidden option using Vim script and the API. This does also mean
that trying to set a hidden option will now give an error instead of just being
ignored.
Problem: tests: no error check when setting global 'briopt'
Solution: also parse and check global 'briopt' value (Milly)
closes: vim/vim#15911b38700ac81
Co-authored-by: Milly <milly.ca@gmail.com>
Problem: tests: no error check when setting global 'cc'
Solution: also parse and check global 'cc' value (Milly)
closes: vim/vim#15914a441a3eaab
Co-authored-by: Milly <milly.ca@gmail.com>
Problem: tests: no error check when setting global 'isk'
Solution: also parse and check global 'isk' value (Milly)
closes: vim/vim#159155e7a6a4a10
Co-authored-by: Milly <milly.ca@gmail.com>
Problem: tests: no error check when setting global 'fdm' to empty value
Solution: Also check global 'fdm' value for being empty (Milly).
closes: vim/vim#15916142cad1f88
Co-authored-by: Milly <milly.ca@gmail.com>
Problem: tests: minor issues in gen_opt_test.vim
Solution: fix restore value for 'undolevels', fix comment, fix
wrong cpo value, add equality test for global-local options on
switchback (Milly).
closes: vim/vim#15913231480f975
Cherry-pick gen_opt_test.vim change from patch 9.1.0807.
Co-authored-by: Milly <milly.ca@gmail.com>
Problem: testing of options can be further improved
Solution: split the generated option test into test_options_all.vim,
add more test cases, save and restore values, fix use-after-free
closes: vim/vim#158946eca04e9f1
Co-authored-by: Milly <milly.ca@gmail.com>
Problem: tests: Test_set_values() is not comprehensive enough
Solution: Add a lot more test cases (Milly)
closes: vim/vim#15892cc15bbcbc4
Co-authored-by: Milly <milly.ca@gmail.com>
Problem: Insufficient test coverage for validation of option values.
Solution: Port Vim's gen_opt_test.vim and make it work with Nvim.
vim-patch:9.1.0760: tests: no error reported, if gen_opt_test.vim fails
vim-patch:9.1.0791: tests: errors in gen_opt_test.vim are not shown
