Mini.test get value from "vim.fn.getreg('*')" ?

[xixiaofinland]

I understand many APIs in fn has been exposed to child so vim.fn equals to child.fn.
But both the last 2 lines retrieve value from the current Nvim running instance (they one I'm editing the test file) rather than the child. Why is it so while the vim.bo ones work as expected?

T['copy_apex_name()']['return apex name'] = function()
  local apex_name = 'SfProject'
  local lua_cmd = string.format('edit tests/dir/sf-project/%s.cls', apex_name)
  child.cmd(lua_cmd)

  child.type_keys('<leader>cc') -- copy name 'SfProject' into "*" registration

  eq(child.lua_get('vim.bo.filetype'), 'apex')  -- works
  eq(child.bo.filetype, 'apex')  -- works

  eq(child.lua_get('vim.fn.getreg("*")'), apex_name)  -- it gets the registration value from the current Nvim instance rather than the test child.
  eq(child.fn.getreg("*"), apex_name) -- same as above line
end

end

[xixiaofinland]

So the Yanked_value below is a current yanked value in my running Nvim instance.

Test result:

Fails (1) and Notes (0)
FAIL in tests/test_apis.lua | copy_apex_name() | return apex name:
  Failed expectation for equality.
  Left:  "Yanked_value"
  Right: "SfProject"
  Traceback:
    tests/test_apis.lua:69

make: *** [Makefile:3: test] Error 1

[echasnovski]

Unfortunately, working with system register is indeed a bit messy. The reason (I think) is mostly because it is something shared by both instances and that Neovim has special treatment of system clipboard (see :h clipboard).

Here is one example of how I get over it.

---

...
child.type_keys('<leader>cc') -- copy name 'SfProject' into "*" registration
...

The answer would have been more helpful if you posted a fully reproducible (and small-ish) test case. For example, the following test case passes locally for me:

T['tmp'] = function()
  child.fn.setreg('*', 'Hello')
  eq(child.fn.getreg('*'), 'Hello')
end

[xixiaofinland]

Interesting, your 'temp' indeed passes. Here is the function it runs with <leader>cc, it should be functional-wise identical to your passed test case.

Meanwhile, I'm debugging it. When I invoke the function child.lua([[Util.copy_apex_name()]]) instead of user typing, it works as expected.

-- Copy current file name without dot-after, e.g. copy "Hello" from "Hello.cls"
M.copy_apex_name = function()
  local file_name = vim.split(vim.fn.expand("%:t"), ".", { trimempty = true, plain = true })[1]
  vim.fn.setreg('*', file_name)
  vim.notify(string.format('"%s" copied.', file_name), vim.log.levels.INFO)
end