Using Angular language server on older projects with Neovim's LSP client

If you’re using https://github.com/neovim/nvim-lspconfig Angular server in an older project, in my case one with version six, you’re probably facing many issues and having a bad experience. That may be due to a missing parameter on the server command.

To fix this, try setting up the server like this:

local languageServerPath = vim.fn.stdpath("config").."/languageserver"
local cmd = {"ngserver", "--stdio", "--tsProbeLocations", languageServerPath , "--ngProbeLocations", languageServerPath, "--viewEngine"}

lspconfig.angularls.setup{
    on_attach = on_attach,
    capabilities = capabilities,
    cmd = cmd,
    on_new_config = function(new_config, new_root_dir)
        new_config.cmd = cmd
    end,
}

The key here is the --viewEngine argument, that maker the language service use it’s legacy configuration, rather than the newer, known as Angular Ivy.

Mind that the languageServerPath variable is the path to the location where @angular/language-service and typescript are installed.

Waiting for this issue to provide further information on the solution.