feat: to-pipe command

flake.nix

@@ -115,7 +115,7 @@
             src = self.outPath;
             inherit version elixir;
             pname = "next-ls-deps";
-            hash = "sha256-GwIxmja8IcgbeKhdiQflhe5Oxq8KiYbLBNLIMkT4HBc=";
+            hash = "sha256-BteNxUWcubVZ/SrFeBxKKV7KHmR39H50kUVaUz53dJs=";
             mixEnv = "prod";
           };
 

lib/next_ls.ex

@@ -24,7 +24,9 @@ defmodule NextLS do
   alias GenLSP.Requests.TextDocumentFormatting
   alias GenLSP.Requests.TextDocumentHover
   alias GenLSP.Requests.TextDocumentReferences
+  alias GenLSP.Requests.WorkspaceApplyEdit
   alias GenLSP.Requests.WorkspaceSymbol
+  alias GenLSP.Structures.ApplyWorkspaceEditParams
   alias GenLSP.Structures.CodeActionContext
   alias GenLSP.Structures.CodeActionOptions
   alias GenLSP.Structures.CodeActionParams
@@ -44,6 +46,7 @@ defmodule NextLS do
   alias GenLSP.Structures.TextDocumentItem
   alias GenLSP.Structures.TextDocumentSyncOptions
   alias GenLSP.Structures.TextEdit
+  alias GenLSP.Structures.WorkspaceEdit
   alias GenLSP.Structures.WorkspaceFoldersChangeEvent
   alias NextLS.DB
   alias NextLS.Definition
@@ -137,6 +140,11 @@ defmodule NextLS do
              nil
            end,
          document_formatting_provider: true,
+         execute_command_provider: %GenLSP.Structures.ExecuteCommandOptions{
+           commands: [
+             "to-pipe"
+           ]
+         },
          hover_provider: true,
          workspace_symbol_provider: true,
          document_symbol_provider: true,
@@ -602,6 +610,57 @@ defmodule NextLS do
       {:reply, [], lsp}
   end
 
+  def handle_request(
+        %GenLSP.Requests.WorkspaceExecuteCommand{
+          params: %GenLSP.Structures.ExecuteCommandParams{command: command} = params
+        },
+        lsp
+      ) do
+    reply =
+      case command do
+        "to-pipe" ->
+          [arguments] = params.arguments
+
+          uri = arguments["uri"]
+          position = arguments["position"]
+          text = lsp.assigns.documents[uri]
+
+          NextLS.Commands.ToPipe.run(%{
+            uri: uri,
+            text: text,
+            position: position
+          })
+
+        _ ->
+          NextLS.Logger.show_message(lsp.logger, :warning, "[Next LS] Unknown workspace command: #{command}")
+          nil
+      end
+
+    case reply do
+      %WorkspaceEdit{} = edit ->
+        GenLSP.request(lsp, %WorkspaceApplyEdit{
+          id: System.unique_integer([:positive]),
+          params: %ApplyWorkspaceEditParams{label: "Pipe", edit: edit}
+        })
+
+      _reply ->
+        :ok
+    end
+
+    {:reply, reply, lsp}
+  rescue
+    e ->
+      NextLS.Logger.show_message(
+        lsp.assigns.logger,
+        :error,
+        "[Next LS] #{command} has failed, see the logs for more details"
+      )
+
+      NextLS.Logger.error(lsp.assigns.logger, Exception.format_banner(:error, e, __STACKTRACE__))
+
+      {:reply, nil, lsp}
+  end
+
   def handle_request(%Shutdown{}, lsp) do
     {:reply, nil, assign(lsp, exit_code: 0)}
   end

lib/next_ls/commands/to_pipe.ex

@@ -0,0 +1,116 @@
+defmodule NextLS.Commands.ToPipe do
+  @moduledoc false
+  import Schematic
+
+  alias GenLSP.Enumerations.ErrorCodes
+  alias GenLSP.Structures.Position
+  alias GenLSP.Structures.Range
+  alias GenLSP.Structures.TextEdit
+  alias GenLSP.Structures.WorkspaceEdit
+  alias NextLS.EditHelpers
+  alias Sourceror.Zipper, as: Z
+
+  defp opts do
+    map(%{
+      position: Position.schematic(),
+      uri: str(),
+      text: list(str())
+    })
+  end
+
+  def run(opts) do
+    with {:ok, %{text: text, uri: uri, position: position}} <- unify(opts(), Map.new(opts)),
+         {:ok, ast} = parse(text),
+         {:ok, {t, m, [argument | rest]} = original} <- get_node(ast, position) do
+      dbg(original)
+      range = Sourceror.get_range(original)
+      dbg(range)
+      text |> Enum.join("\n") |> NextLS.Commands.ToPipe.decorate(range) |> dbg()
+      range = make_range(original)
+      indent = EditHelpers.get_indent(text, range.start.line)
+      piped = {:|>, [], [argument, {t, m, rest}]}
+
+      %WorkspaceEdit{
+        changes: %{
+          uri => [
+            %TextEdit{
+              new_text:
+                EditHelpers.add_indent_to_edit(
+                  Macro.to_string(piped),
+                  indent
+                ),
+              range: range
+            }
+          ]
+        }
+      }
+    else
+      {:error, message} ->
+        %GenLSP.ErrorResponse{code: ErrorCodes.parse_error(), message: inspect(message)}
+    end
+  end
+
+  defp parse(lines) do
+    lines
+    |> Enum.join("\n")
+    |> Spitfire.parse()
+    |> case do
+      {:error, ast, _errors} ->
+        {:ok, ast}
+
+      other ->
+        other
+    end
+  end
+
+  def decorate(code, range) do
+    code
+    |> Sourceror.patch_string([%{range: range, change: &"«#{&1}»"}])
+    |> String.trim_trailing()
+  end
+
+  defp make_range(original_ast) do
+    range = Sourceror.get_range(original_ast)
+
+    %Range{
+      start: %Position{line: range.start[:line] - 1, character: range.start[:column] - 1},
+      end: %Position{line: range.end[:line] - 1, character: range.end[:column] - 1}
+    }
+  end
+
+  def get_node(ast, pos) do
+    pos = [line: pos.line + 1, column: pos.character + 1]
+
+    result =
+      ast
+      |> Z.zip()
+      |> Z.traverse(nil, fn tree, acc ->
+        node = Z.node(tree)
+        range = Sourceror.get_range(node)
+
+        if not is_nil(range) and
+             (match?({{:., _, _}, _, [_ | _]}, node) or
+                match?({t, _, [_ | _]} when t not in [:., :__aliases__], node)) do
+          if Sourceror.compare_positions(range.start, pos) == :lt &&
+               Sourceror.compare_positions(range.end, pos) == :gt do
+            {tree, node}
+          else
+            {tree, acc}
+          end
+        else
+          {tree, acc}
+        end
+      end)
+
+    case result do
+      {_, nil} ->
+        {:error, "could not find an argument to extract at the cursor position"}
+
+      {_, {_t, _m, []}} ->
+        {:error, "could not find an argument to extract at the cursor position"}
+
+      {_, {_t, _m, [_argument | _rest]} = node} ->
+        {:ok, node}
+    end
+  end
+end

lib/next_ls/helpers/edit_helpers.ex

@@ -0,0 +1,41 @@
+defmodule NextLS.EditHelpers do
+  @moduledoc false
+
+  @doc """
+  This adds indentation to all lines except the first since the LSP expects a range for edits,
+  where we get the range with the already original indentation for starters.
+
+  It also skips empty lines since they don't need indentation.
+  """
+  @spec add_indent_to_edit(text :: String.t(), indent :: String.t()) :: String.t()
+  @blank_lines ["", "\n"]
+  def add_indent_to_edit(text, indent) do
+    [first | rest] = String.split(text, "\n")
+
+    if rest != [] do
+      indented =
+        Enum.map_join(rest, "\n", fn line ->
+          if line not in @blank_lines do
+            indent <> line
+          else
+            line
+          end
+        end)
+
+      first <> "\n" <> indented
+    else
+      first
+    end
+  end
+
+  @doc """
+  Gets the indentation level at the line number desired
+  """
+  @spec get_indent(text :: [String.t()], line :: non_neg_integer()) :: String.t()
+  def get_indent(text, line) do
+    text
+    |> Enum.at(line)
+    |> then(&Regex.run(~r/^(\s*).*/, &1))
+    |> List.last()
+  end
+end

mix.exs

@@ -63,6 +63,7 @@ defmodule NextLS.MixProject do
       {:req, "~> 0.3"},
       {:schematic, "~> 0.2"},
       {:spitfire, github: "elixir-tools/spitfire"},
+      {:sourceror, "~> 1.0"},
 
       {:opentelemetry, "~> 1.3"},
       {:opentelemetry_api, "~> 1.2"},

mix.lock

@@ -43,7 +43,8 @@
   "ranch": {:hex, :ranch, "1.8.0", "8c7a100a139fd57f17327b6413e4167ac559fbc04ca7448e9be9057311597a1d", [:make, :rebar3], [], "hexpm", "49fbcfd3682fab1f5d109351b61257676da1a2fdbe295904176d5e521a2ddfe5"},
   "req": {:hex, :req, "0.4.0", "1c759054dd64ef1b1a0e475c2d2543250d18f08395d3174c371b7746984579ce", [:mix], [{:brotli, "~> 0.3.1", [hex: :brotli, repo: "hexpm", optional: true]}, {:ezstd, "~> 1.0", [hex: :ezstd, repo: "hexpm", optional: true]}, {:finch, "~> 0.9", [hex: :finch, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:mime, "~> 1.6 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:nimble_csv, "~> 1.0", [hex: :nimble_csv, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: true]}], "hexpm", "f53eadc32ebefd3e5d50390356ec3a59ed2b8513f7da8c6c3f2e14040e9fe989"},
   "schematic": {:hex, :schematic, "0.2.1", "0b091df94146fd15a0a343d1bd179a6c5a58562527746dadd09477311698dbb1", [:mix], [{:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "0b255d65921e38006138201cd4263fd8bb807d9dfc511074615cd264a571b3b1"},
-  "spitfire": {:git, "https://github.com/elixir-tools/spitfire.git", "12a1827821265170a58e40b5ffd2bb785f789d91", []},
+  "sourceror": {:hex, :sourceror, "1.0.1", "ec2c41726d181adce888ac94b3f33b359a811b46e019c084509e02c70042e424", [:mix], [], "hexpm", "28225464ffd68bda1843c974f3ff7ccef35e29be09a65dfe8e3df3f7e3600c57"},
+  "spitfire": {:git, "https://github.com/elixir-tools/spitfire.git", "adb18c8f4479ddddf2eef844211e0861bd856fdb", []},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.7", "354c321cf377240c7b8716899e182ce4890c5938111a1296add3ec74cf1715df", [:make, :mix, :rebar3], [], "hexpm", "fe4c190e8f37401d30167c8c405eda19469f34577987c76dde613e838bbc67f8"},
   "styler": {:hex, :styler, "0.8.1", "f3c0f65023e4bfbf7e7aa752d128b8475fdabfd30f96ee7314b84480cc56e788", [:mix], [], "hexpm", "1aa48d3aa689a639289af3d8254d40e068e98c083d6e5e3d1a695e71a147b344"},
   "telemetry": {:hex, :telemetry, "1.2.1", "68fdfe8d8f05a8428483a97d7aab2f268aaff24b49e0f599faa091f1d4e7f61c", [:rebar3], [], "hexpm", "dad9ce9d8effc621708f99eac538ef1cbe05d6a874dd741de2e689c47feafed5"},

test/next_ls/commands/pipe_test.exs

@@ -0,0 +1,85 @@
+defmodule NextLS.Commands.PipeTest do
+  use ExUnit.Case, async: true
+
+  import GenLSP.Test
+  import NextLS.Support.Utils
+
+  @moduletag :tmp_dir
+  @moduletag root_paths: ["my_proj"]
+
+  setup %{tmp_dir: tmp_dir} do
+    File.mkdir_p!(Path.join(tmp_dir, "my_proj/lib"))
+    File.write!(Path.join(tmp_dir, "my_proj/mix.exs"), mix_exs())
+
+    cwd = Path.join(tmp_dir, "my_proj")
+
+    foo_path = Path.join(cwd, "lib/foo.ex")
+
+    foo = """
+    defmodule Foo do
+      def to_list() do
+        Enum.to_list(Map.new())
+      end
+    end
+    """
+
+    File.write!(foo_path, foo)
+
+    bar_path = Path.join(cwd, "lib/bar.ex")
+
+    bar = """
+    defmodule Bar do
+      def to_list() do
+        Map.new() |> Enum.to_list()
+      end
+    end
+    """
+
+    File.write!(bar_path, bar)
+
+    [foo: foo, foo_path: foo_path, bar: bar, bar_path: bar_path]
+  end
+
+  setup :with_lsp
+
+  setup context do
+    assert :ok == notify(context.client, %{method: "initialized", jsonrpc: "2.0", params: %{}})
+    assert_is_ready(context, "my_proj")
+    assert_compiled(context, "my_proj")
+    assert_notification "$/progress", %{"value" => %{"kind" => "end", "message" => "Finished indexing!"}}
+
+    did_open(context.client, context.foo_path, context.foo)
+    did_open(context.client, context.bar_path, context.bar)
+    context
+  end
+
+  test "transforms nested function expressions to pipes", %{client: client, foo_path: foo} do
+    foo_uri = uri(foo)
+    id = 1
+
+    request client, %{
+      method: "workspace/executeCommand",
+      id: id,
+      jsonrpc: "2.0",
+      params: %{
+        command: "to-pipe",
+        arguments: [%{uri: foo_uri, position: %{line: 2, character: 19}}]
+      }
+    }
+
+    assert_request(client, "workspace/applyEdit", 500, fn params ->
+      assert %{"edit" => edit, "label" => "Pipe"} = params
+
+      assert %{
+               "changes" => %{
+                 ^foo_uri => [%{"newText" => text, "range" => range}]
+               }
+             } = edit
+
+      expected = "Map.new() |> Enum.to_list()"
+      assert text == expected
+      assert range["start"] == %{"character" => 4, "line" => 2}
+      assert range["end"] == %{"character" => 27, "line" => 2}
+    end)
+  end
+end