dotfiles/nvim/after/lsp/rust_analyzer.lua

-- Rust LSP adding in some additions for extensive diagnostics

-- Section from nvim-lspconfig
-- local function reload_workspace()
--     local clients = vim.lsp.get_clients { bufnr = bufnr, name = 'rust_analyzer' }
--     for _, client in ipairs(clients) do
--         vim.notify 'Reloading Cargo Workspace'
--         client:request('rust-analyzer/reloadWorkspace', nil, function(err)
--             if err then
--                 error(tostring(err))
--             end
--             vim.notify 'Cargo workspace reloaded'
--         end, 0)
--     end
-- end
--
-- local function user_sysroot_src()
--     return vim.tbl_get(vim.lsp.config['rust_analyzer'], 'settings', 'rust-analyzer', 'cargo', 'sysrootSrc')
-- end
--
-- local function default_sysroot_src()
--     local sysroot = vim.tbl_get(vim.lsp.config['rust_analyzer'], 'settings', 'rust-analyzer', 'cargo', 'sysroot')
--     if not sysroot then
--         local rustc = os.getenv 'RUSTC' or 'rustc'
--         local result = vim.system({ rustc, '--print', 'sysroot' }, { text = true }):wait()
--
--         local stdout = result.stdout
--
--         if result.code == 0 and stdout then
--             if string.sub(stdout, #stdout) == '\n' then
--                 if #stdout > 1 then
--                     sysroot = string.sub(stdout, 1, #stdout - 1)
--                 else
--                     sysroot = ''
--                 end
--             else
--                 sysroot = stdout
--             end
--         end
--     end
--
--     return sysroot and vim.fs.joinpath(sysroot, 'lib/rustlib/src/rust/library') or nil
-- end
--
-- local function is_library(fname)
--     local user_home = vim.fs.normalize(vim.env.HOME)
--     local cargo_home = os.getenv 'CARGO_HOME' or user_home .. '/.cargo'
--     local registry = cargo_home .. '/registry/src'
--     local git_registry = cargo_home .. '/git/checkouts'
--
--     local rustup_home = os.getenv 'RUSTUP_HOME' or user_home .. '/.rustup'
--     local toolchains = rustup_home .. '/toolchains'
--
--     local sysroot_src = user_sysroot_src() or default_sysroot_src()
--
--     for _, item in ipairs { toolchains, registry, git_registry, sysroot_src } do
--         if item and vim.fs.relpath(item, fname) then
--             local clients = vim.lsp.get_clients { name = 'rust_analyzer' }
--             return #clients > 0 and clients[#clients].config.root_dir or nil
--         end
--     end
-- end
--
-- return {
--   cmd = { 'rust-analyzer' },
--   filetypes = { 'rust' },
--   root_dir = function(bufnr, on_dir)
--     local fname = vim.api.nvim_buf_get_name(bufnr)
--     local reused_dir = is_library(fname)
--     if reused_dir then
--       on_dir(reused_dir)
--       return
--     end
--
--     local cargo_crate_dir = vim.fs.root(fname, { 'Cargo.toml' })
--     local cargo_workspace_root
--
--     if cargo_crate_dir == nil then
--       on_dir(
--         vim.fs.root(fname, { 'rust-project.json' })
--           or vim.fs.dirname(vim.fs.find('.git', { path = fname, upward = true })[1])
--       )
--       return
--     end
--
--     local cmd = {
--       'cargo',
--       'metadata',
--       '--no-deps',
--       '--format-version',
--       '1',
--       '--manifest-path',
--       cargo_crate_dir .. '/Cargo.toml',
--     }
--
--     vim.system(cmd, { text = true }, function(output)
--       if output.code == 0 then
--         if output.stdout then
--           local result = vim.json.decode(output.stdout)
--           if result['workspace_root'] then
--             cargo_workspace_root = vim.fs.normalize(result['workspace_root'])
--           end
--         end
--
--         on_dir(cargo_workspace_root or cargo_crate_dir)
--       else
--         vim.schedule(function()
--           vim.notify(('[rust_analyzer] cmd failed with code %d: %s\n%s'):format(output.code, cmd, output.stderr))
--         end)
--       end
--     end)
--   end,
--   capabilities = {
--     experimental = {
--       serverStatusNotification = true,
--       commands = {
--         commands = {
--           'rust-analyzer.showReferences',
--           'rust-analyzer.runSingle',
--           'rust-analyzer.debugSingle',
--         },
--       },
--     },
--   },
--   ---@type lspconfig.settings.rust_analyzer
--   settings = {
--     ['rust-analyzer'] = {
--       lens = {
--         debug = { enable = true },
--         enable = true,
--         implementations = { enable = true },
--         references = {
--           adt = { enable = true },
--           enumVariant = { enable = true },
--           method = { enable = true },
--           trait = { enable = true },
--         },
--         run = { enable = true },
--         updateTest = { enable = true },
--       },
--     },
--   },
--   before_init = function(init_params, config)
--     -- See https://github.com/rust-lang/rust-analyzer/blob/eb5da56d839ae0a9e9f50774fa3eb78eb0964550/docs/dev/lsp-extensions.md?plain=1#L26
--     if config.settings and config.settings['rust-analyzer'] then
--       init_params.initializationOptions = config.settings['rust-analyzer']
--     end
--     ---@param command table{ title: string, command: string, arguments: any[] }
--     vim.lsp.commands['rust-analyzer.runSingle'] = function(command)
--       local r = command.arguments[1]
--       local cmd = { 'cargo', unpack(r.args.cargoArgs) }
--       if r.args.executableArgs and #r.args.executableArgs > 0 then
--         vim.list_extend(cmd, { '--', unpack(r.args.executableArgs) })
--       end
--
--       local proc = vim.system(cmd, { cwd = r.args.cwd, env = r.args.environment })
--
--       local result = proc:wait()
--
--       if result.code == 0 then
--         vim.notify(result.stdout, vim.log.levels.INFO)
--       else
--         vim.notify(result.stderr, vim.log.levels.ERROR)
--       end
--     end
--   end,
--   on_attach = function(_, bufnr)
--     vim.api.nvim_buf_create_user_command(bufnr, 'LspCargoReload', function()
--       reload_workspace(bufnr)
--     end, { desc = 'Reload current cargo workspace' })
--   end,
-- }

return {
    cmd = { 'rust-analyzer' },
    filetypes = { 'rust' },
    settings = {
        ['rust_analyzer'] = {
            check = {
                command = 'clippy',
                extraArgs = {
                    '--',
                    '-D clippy::all',
                    '-W clippy::pedantic',
                    '-W clippy::restriction'
                },
            },
            diagnostics = {
                enable = true,
                experimental = {
                    enable = true,
                }
            }
        }
    }
}