LuaLS-style quoted literal aliases cause false type mismatches #1271

Description

LuaLS-style string literal aliases use an outer single-quoted annotation string around a quoted literal, for example ---| '"fallback"'. EmmyLua accepts the syntax but does not match the Lua value 'fallback' against it, causing a false param-type-mismatch.

This affects existing Neovim plugin annotations. For example, stevearc/conform.nvim defines conform.LspFormatOpts this way, so its documented default_format_opts = { lsp_format = 'fallback' } configuration is reported as incompatible with conform.setupOpts.

Minimal reproduction

.emmyrc.json:

{}

repro.lua:

---@alias LspFormat
---| '"never"'
---| '"fallback"'

---@class (exact) DefaultOpts
---@field lsp_format? LspFormat

---@class (exact) SetupOpts
---@field default_format_opts? DefaultOpts

---@param opts? SetupOpts
local function setup(opts) end

setup {
  default_format_opts = {
    lsp_format = 'fallback',
  },
}

Run:

emmylua_check .

Actual behavior

warning: expected `SetupOpts?` but found `{ default_format_opts = table }`. [param-type-mismatch]

The same mismatch is reported by emmylua_ls when configuring Conform:

expected `conform.setupOpts?` but found `{ default_format_opts = table }`. [param-type-mismatch]

Expected behavior

No type mismatch. This literal alias spelling is used by LuaLS annotations in existing Lua projects and should describe the value fallback, not a string containing quote characters.

Changing the alias to EmmyLua's spelling makes the reproduction pass:

---@alias LspFormat
---| "never"
---| "fallback"

Environment

• emmylua_check 0.25.1
• emmylua_ls 0.25.1
• Linux x86_64
• Real-world occurrence: https://github.com/stevearc/conform.nvim/blob/016802de402556da54c36bd7359b441266b01cdd/lua/conform/types.lua#L68-L73