neovim/test/functional/lua/ui_spec.lua

local helpers = require('test.functional.helpers')(after_each)
local eq = helpers.eq
local exec_lua = helpers.exec_lua
local clear = helpers.clear

describe('vim.ui', function()
  before_each(function()
    clear()
  end)


  describe('select', function()
    it('can select an item', function()
      local result = exec_lua[[
        local items = {
          { name = 'Item 1' },
          { name = 'Item 2' },
        }
        local opts = {
          format_item = function(entry)
            return entry.name
          end
        }
        local selected
        local cb = function(item)
          selected = item
        end
        -- inputlist would require input and block the test;
        local choices
        vim.fn.inputlist = function(x)
          choices = x
          return 1
        end
        vim.ui.select(items, opts, cb)
        vim.wait(100, function() return selected ~= nil end)
        return {selected, choices}
      ]]
      eq({ name = 'Item 1' }, result[1])
      eq({
        'Select one of:',
        '1: Item 1',
        '2: Item 2',
      }, result[2])
    end)
  end)
end)