[mini.test] vim.fn.confirm seems to always use the default choice

[elanmed]

Contributing guidelines

• I have read CODE_OF_CONDUCT.md

Module(s)

mini.test

Question

👋 I'm writing tests for a small file tree plugin, and I'm running into an issue where vim.fn.confirm seems to automatically trigger and use the default choice. I was able to reproduce this using just these files:

-- lua/confirm/init.lua

local M = {}

M.run = function()
  -- roughly my use-case
  local dirname = vim.fs.joinpath(vim.fs.dirname(vim.api.nvim_buf_get_name(0)), '/')
  local create_path = vim.fn.input("Create a file: ", dirname)
  local option = vim.fn.confirm(("Create %s?"):format(create_path), "&Yes\n&No", 2)
  if option == 1 then
    vim.fn.writefile({}, create_path)
    return
  end
  vim.notify("Aborting create", vim.log.levels.INFO)
end

return M

-- tests/test_run.lua

require "mini.test".setup()

local expect = MiniTest.expect
local child = MiniTest.new_child_neovim()

local T = MiniTest.new_set {
  hooks = {
    pre_case = function()
      child.restart { "-u", "scripts/minimal_init.lua", }
      child.lua [[M = require('confirm')]]
      child.o.lines = 30
      child.o.columns = 30
    end,
    post_once = child.stop,
  },
}

T["confirm"] = function()
  child.lua_notify [[M.run()]]
  expect.reference_screenshot(child.get_screenshot())

  child.type_keys("tester.txt")
  expect.reference_screenshot(child.get_screenshot())

  child.type_keys("<CR>")
  expect.reference_screenshot(child.get_screenshot())

  vim.print(child.cmd_capture("messages"))
end

return T

With this output:

nvim --headless --noplugin -u ./scripts/minimal_init.lua -c "lua MiniTest.run()"
Total number of cases: 1
Total number of groups: 1

tests/test_run.lua: Aborting createo

Fails (0) and Notes (0)

As you can see, Aborting create is printed despite that fact that no Y/1 was entered - submitting the vim.fn.input with <CR> also triggered the vim.fn.confirm to use the default value.

I haven't been able to find anything relevant online, has anyone encountered issues with vim.fn.confirm before? Any help is appreciated 🙏

[echasnovski]

Yes, unfortunately, vim.fn.confirm() does tend to behave like this. I am not sure why, but mocking the method works pretty good here. This is what I use for 'mini.files' testing. It can then be used before invoking action that would require confirm (like this). Then validate arguments with which it was called (something like this).

The same approach is used in Neovim itself for vim.pack testing.

So here it would be something like this:

T["confirm"] = function()
  child.lua_notify [[M.run()]]
  child.type_keys("tester.txt")
  mock_confirm(1)
  child.type_keys("<CR>")

  eq(child.cmd_capture("messages"), '')
end

[elanmed]

ah interesting, thanks for the quick response!