Dbg backend for debugger (#974)

* add dbg backend

* break on dbg

* continue

* stop session

* properly get module code

* overwrite bindings

* step through pipes

* pass env to eval

* add tests

* continue dbg session

* fix tests on < 1.14

* fixing tests

* remove not needed asserts

* make dbg breakpoints work when debugging in non interpreted mode

* port bugfix from elixir

* get stacktrace from Process.info if not in interpreted mode

* remove not relevant todos

* fix breakpoint type detection

* make sure process is dead

apps/elixir_ls_debugger/lib/debugger.ex

@@ -5,16 +5,26 @@ defmodule ElixirLS.Debugger do
 
   use Application
   alias ElixirLS.Debugger.Output
+  alias ElixirLS.Debugger.Server
 
   @impl Application
   def start(_type, _args) do
     # We don't start this as a worker because if the debugger crashes, we want
     # this process to remain alive to print errors
     {:ok, _pid} = Output.start(Output)
 
-    children = [
-      {ElixirLS.Debugger.Server, name: ElixirLS.Debugger.Server}
-    ]
+    if Version.match?(System.version(), ">= 1.14.0") do
+      Application.put_env(:elixir, :dbg_callback, {Server, :dbg, []})
+    end
+
+    children =
+      if Mix.env() != :test do
+        [
+          {Server, name: Server}
+        ]
+      else
+        []
+      end
 
     opts = [strategy: :one_for_one, name: ElixirLS.Debugger.Supervisor, max_restarts: 0]
     Supervisor.start_link(children, opts)