Use only a single clear() call in some test/functional/vimscript/ test
files whose test cases have very little side effect.
A downside of using a single clear() is that if a crash happens in one
test case, all following test cases in the same file will also fail, but
these functionalities and tests don't change very often.
Specifically, functions that are run in the context of the test runner
are put in module `test/testutil.lua` while the functions that are run
in the context of the test session are put in
`test/functional/testnvim.lua`.
Closes https://github.com/neovim/neovim/issues/27004.
helpers.source() was a hack to work around the lack of anonymous
:source. Its "create tempfile" behavior is not a required part of most
tests that use it.
Some tests still need the old "create tempfile" behavior either because
they test SID behavior, or because of missing nvim_exec features: #16071
Problem
- `redir_exec` is obsolete, but it keeps getting used in new tests
because people copy existing tests.
- Disadvantages of `redir_exec`:
- Captures extra junk before the actual error/message that we _want_ to test.
- Does not fail on error, unlike e.g. `command()`.
Solution
- Use new functions like `nvim_exec` and `pcall_err`.
Problem: :echomsg and :echoerr do not handle List and Dict like :echo does.
(Daniel Hahler)
Solution: Be more tolerant about the expression result type.
461a7fcfce
Add lua functional tests for :echo,:echon,:echomsg,:echoerr
because nvim did not port "test_" functions from Vim
that modify internal state.
Testing :echoerr via try/catch is sufficient.
