fix: do not add executable to adapter in launch request

[jsternberg]

The adapter would add the executable property to the adapter regardless of whether the request was launch or attach. When attach was used, it would attempt to start dlv on the same port that it was attempting to configure.

This changes it so the executable is not added if attach is used and adds some protection code to prevent the random port assignment from being used with the attach configuration (where it wouldn't work anyway).

Fixes issue mentioned here: #35 (comment)
Solution suggested here: mfussenegger/nvim-dap#1273 (comment)

[leoluz]

@jsternberg Tks for your PR. I'll try to find time to review it in the coming days.

[leoluz]

@jsternberg I am concluding a review in another PR (#78) that will probably cause some conflicts with the code implemented in this one. I'll let you know when that gets merged.

[leoluz]

@jsternberg #78 is merged. Can you please rebase?

[jsternberg]

I'll probably have time to rebase this sometime this week.

[jsternberg]

On vacation and can't really test it that well right now, but I wanted to try and update the PR. The intention is that mode = remote is used if you've launched the program through dlv exec and want to attach to it through that method.

[wilriker]

I encountered the same issue yesterday (and it took me about all day to figure out a working solution - only found this PR this morning when wanting to create my own PR).

I have a working version based on latest main branch. Should I provide it as a separate PR? Otherwise: the implementation of setup_delve_adapter has changed into:

local function setup_delve_adapter(dap, config)
  local args = { "dap", "-l", "127.0.0.1:" .. config.delve.port }
  vim.list_extend(args, config.delve.args)

  dap.adapters.go = function(callback, client_config)
    local delve_config = {
      type = "server",
      port = config.delve.port,
      executable = {
        command = config.delve.path,
        args = args,
        detached = config.delve.detached,
        cwd = config.delve.cwd,
      },
      options = {
        initialize_timeout_sec = config.delve.initialize_timeout_sec,
      },
    }
    if client_config.port == nil then
      callback(delve_config)
      return
    end

    local host = client_config.host
    if host == nil then
      host = "127.0.0.1"
    end

    local listener_addr = host .. ":" .. client_config.port
    delve_config.port = client_config.port

    if client_config.request == "attach" and client_config.mode == "remote" then
      -- if we want to attach to an existing debugger only we have to remove the executable section
      -- otherwise nvim-dap will try to start a new debugger at the same port and fails (since port is already bound)
      client_config.executable = nil
    else
      delve_config.executable.args = { "dap", "-l", listener_addr }
    end

    callback(delve_config)
  end
end

[jsternberg]

I'm back from vacation so I can probably test out my own change today.