test: reduce `exec_lua` calls

`exec_lua` makes code slighly harder to read, so it's beneficial to
remove it in cases where it's possible or convenient.

Not all `exec_lua` calls should be removed even if the test passes as it
changes the semantics of the test even if it happens to pass.

From https://github.com/neovim/neovim/pull/28155#discussion_r1548185779:

"Note for tests like this, which fundamentally are about conversion, you
end up changing what conversion you are testing. Even if the result
happens to be same (as they often are, as we like the rules to be
consistent if possible), you are now testing the RPC conversion rules
instead of the vim script to in-process lua conversion rules."

From https://github.com/neovim/neovim/pull/28155#discussion_r1548190152:

"A test like this specifies that the cursor is valid immediately and not
after a separate cycle of normal (or an other input-processing) mode."

1 files changed, 4 insertions, 3 deletions

diff --git a/test/functional/plugin/health_spec.lua b/test/functional/plugin/health_spec.lua
index 9306180c40..8416f0e5f7 100644
--- a/test/functional/plugin/health_spec.lua
+++ b/test/functional/plugin/health_spec.lua
@@ -8,7 +8,8 @@ local eq, neq, matches = helpers.eq, helpers.neq, helpers.matches
 local getcompletion = helpers.fn.getcompletion
 local insert = helpers.insert
 local source = helpers.source
-local exec_lua = helpers.exec_lua
+local fn = helpers.fn
+local api = helpers.api
 
 describe(':checkhealth', function()
   it('detects invalid $VIMRUNTIME', function()
@@ -381,7 +382,7 @@ describe(':checkhealth window', function()
 
   it('opens in tab', function()
     -- create an empty buffer called "my_buff"
-    exec_lua 'vim.api.nvim_create_buf(false, true)'
+    api.nvim_create_buf(false, true)
     command('file my_buff')
     command('checkhealth success1')
     -- define a function that collects all buffers in each tab
@@ -400,7 +401,7 @@ describe(':checkhealth window', function()
                 return buffs
         endfunction
     ]])
-    local buffers_per_tab = exec_lua('return vim.fn.CollectBuffersPerTab()')
+    local buffers_per_tab = fn.CollectBuffersPerTab()
     eq(buffers_per_tab, { tab1 = { 'my_buff' }, tab2 = { 'health://' } })
   end)
 end)