CDS LSP NVIM Quick HowTo

Setup

TBD: needs to be generalized
This HowTo assumes that you have a $HOME/bin folder that is in your $PATH.
This repository needs to be installed $HOME/bin/cds.

• run ./cds-install.
  This installs the newest cds-lsp from npmjs.com
  into the folder cds-lsp.
• add the following configuration to your init.lua

If you have problems with the installation delete the file npm-shrinkwraps.json. This file contains some references to an internal SAP repository which is not needed

local lspconfig = require'lspconfig'
local configs = require'lspconfig.configs'
local on_attach = function(client, bufnr)
    vim.notify("sapcds_lsp attached to buffer", vim.log.levels.WARN)
    local function buf_set_option(...) vim.api.nvim_buf_set_option(bufnr, ...) end
    buf_set_option('omnifunc', 'v:lua.vim.lsp.omnifunc')
    if client.server_capabilities.documentFormattingProvider then
      vim.cmd("nnoremap <silent><buffer> gf :lua vim.lsp.buf.format({async = true})<CR>")
    end

    if client.server_capabilities.documentRangeFormattingProvider then
      vim.cmd("xnoremap <silent><buffer> gf :lua vim.lsp.buf.range_formatting({})<CR>")
    end
end

configs.sapcds_lsp = {
  default_config = {
    cmd = {vim.fn.expand("$HOME/bin/cds/cds-start")}; -- this executable must be there
    filetypes = {'cds'};
    root_dir = function(fname)
      return vim.fn.getcwd()
    end;
    settings = {};
  };
}
if lspconfig.sapcds_lsp.setup then
  vim.notify("Calling sapcds_lsp setup", vim.log.levels.WARN)
  lspconfig.sapcds_lsp.setup{
    on_attach = on_attach, 
    autostart = true ,
    capabilities = require('cmp_nvim_lsp').default_capabilities(vim.lsp.protocol.make_client_capabilities()),
  }
end

Configure shortcuts / key mappings in NVIM

There are general key mappings and a few key mappings only for CDS files
(should probalby generalize the latter ones and make all key mappings only available when a lsp server is attached)

Helper function in lua.init

local function map(mode, lhs, rhs, opts)
  local options = {noremap = true}
  if opts then options = vim.tbl_extend('force', options, opts) end
  vim.api.nvim_set_keymap(mode, lhs, rhs, options)
end

General key mappings

-- map('n', 'gd', ':lua vim.lsp.buf.definition()<CR>')
map('n', 'gh', ':lua vim.lsp.buf.hover()<CR>')
map('n', 'gi', ':lua vim.lsp.buf.document_highlight()<CR>')
map('n', 'gl', ':lua vim.lsp.buf.clear_references()<CR>')
map('i', '<C-k>', '<ESC>:lua vim.lsp.buf.hover()<CR>')
map('n', 'ga', ':lua vim.lsp.buf.code_action()<CR>')
map('n', 'gA', ':Telescope lsp_range_code_actions<CR>')
-- map('n', 'gD', ':lua vim.lsp.buf.implementation()<CR>')
map('n', '<c-k>', ':lua vim.lsp.buf.signature_help()<CR>')
-- map('n', 'gr', ':lua vim.lsp.buf.references()<CR>')
map('n', 'gR', ':lua vim.lsp.buf.rename()<CR>')

CDS key mappings

The CDS key mappings gf are defined in the on_attach handler (see above)