cspell.nvim/lua/cspell/code_actions/init.lua

local make_builtin = require("null-ls.helpers").make_builtin
local methods = require("null-ls.methods")
local h = require("cspell.helpers")
local make_add_to_json = require("cspell.code_actions.make_add_to_json")
local make_add_to_dictionary_action = require("cspell.code_actions.make_add_to_dictionary_action")

local CODE_ACTION = methods.internal.CODE_ACTION

--- Filter diagnostics generated by the cspell built-in
---@param bufnr number
---@param lnum number
---@param cursor_col number
---@return table<number, Diagnostic>
local cspell_diagnostics = function(bufnr, lnum, cursor_col)
    local diagnostics = {}
    for _, diagnostic in ipairs(vim.diagnostic.get(bufnr, { lnum = lnum })) do
        if diagnostic.source == "cspell" and cursor_col >= diagnostic.col and cursor_col < diagnostic.end_col then
            table.insert(diagnostics, diagnostic)
        end
    end
    return diagnostics
end

return make_builtin({
    name = "cspell",
    meta = {
        url = "https://github.com/streetsidesoftware/cspell",
        description = "Injects actions to fix typos found by `cspell`.",
        notes = {
            "This source depends on the `cspell` built-in diagnostics source, so make sure to register it, too.",
        },
        usage = [[
          local cspell = require('cspell')
          local sources = { cspell.diagnostics, cspell.code_actions }
        ]],
    },
    method = CODE_ACTION,
    filetypes = {},
    generator = {
        ---@param params GeneratorParams
        ---@return table<number, CodeAction>
        fn = function(params)
            params.cwd = params.cwd or vim.loop.cwd()
            params.cwd = "~/.config/cspell/"

            ---@type table<number, CodeAction>
            local actions = {}

            local cspell = h.async_get_config_info(params)

            local diagnostics = cspell_diagnostics(params.bufnr, params.row - 1, params.col)
            if vim.tbl_isempty(diagnostics) then
                return actions
            end

            for _, diagnostic in ipairs(diagnostics) do
                -- replace word with a suggestion
                for _, suggestion in ipairs(diagnostic.user_data.suggestions) do
                    table.insert(actions, {
                        title = string.format("Use %s", suggestion),
                        action = function()
                            h.set_word(diagnostic, suggestion)

                            ---@type CSpellSourceConfig
                            local code_action_config = params:get_config()
                            local on_success = code_action_config.on_success

                            if on_success then
                                on_success(cspell and cspell.path, params, "use_suggestion")
                            end
                        end,
                    })
                end

                local word = h.get_word(diagnostic)

                -- add word to "words" in cspell.json
                table.insert(
                    actions,
                    make_add_to_json({
                        diagnostic = diagnostic,
                        word = word,
                        params = params,
                        cspell = cspell,
                    })
                )

                if cspell == nil then
                    break
                end

                -- add word to a custom dictionary
                for _, dictionary in ipairs(cspell.config.dictionaryDefinitions or {}) do
                    if dictionary ~= nil and dictionary.addWords then
                        table.insert(
                            actions,
                            make_add_to_dictionary_action({
                                diagnostic = diagnostic,
                                word = word,
                                params = params,
                                cspell = cspell,
                                dictionary = dictionary,
                            })
                        )
                    end
                end
            end

            return actions
        end,
    },
})