refactor: improvements on cursor position to selection conversion

Author: gp-pereira

lib/refactorex.ex

@@ -143,9 +143,19 @@ defmodule Refactorex do
 
     case Parser.parse_inputs(original, range) do
       {:ok, zipper, selection} ->
-        if Refactor.rename_available?(zipper, selection),
-          do: {:ok, Response.send_rename_range(range)},
-          else: {:ok, nil}
+        cond do
+          not Refactor.rename_available?(zipper, selection) ->
+            {:ok, nil}
+
+          match?({:@, _, _}, selection) ->
+            # this is done so that the placeholder
+            # for RenameConstant doesn't include the @
+            range = update_in(range.start.character, &(&1 + 1))
+            {:ok, Response.send_rename_range(range)}
+
+          true ->
+            {:ok, Response.send_rename_range(range)}
+        end
 
       {:error, :parse_error} ->
         {:ok, nil}

lib/refactorex/parser.ex

@@ -27,16 +27,16 @@ defmodule Refactorex.Parser do
       |> String.split(~r/(?<!\\)\n/)
       |> Enum.at(line)
       |> String.split("")
-      |> Enum.split(character)
+      |> Enum.split(character + 1)
 
     %{
       start: %{
         line: line,
-        character: character - 1 - count_while_name(Enum.reverse(left))
+        character: character - count_while_name(Enum.reverse(left))
       },
       end: %{
         line: line,
-        character: character - 1 + count_while_name(right)
+        character: character + count_while_name(right)
       }
     }
   end
@@ -89,7 +89,7 @@ defmodule Refactorex.Parser do
 
   defp count_while_name(characters) do
     Enum.reduce_while(characters, 0, fn i, count ->
-      if String.match?(i, ~r/^[a-zA-Z0-9_?!]+$/),
+      if String.match?(i, ~r/^[a-zA-Z0-9_?!@]+$/),
         do: {:cont, count + 1},
         else: {:halt, count}
     end)

test/parser_test.exs

@@ -4,19 +4,66 @@ defmodule Refactorex.ParserTest do
   alias Refactorex.Parser
 
   describe "position_to_range/2" do
-    test "parse the selected node when passed a position" do
+    test "parse the selected node when passed a position in the beginning" do
       original = """
       defmodule Foo do
+        #   v
         def do_bar?(arg) do
         end
       end
       """
 
-      position = %{line: 1, character: 10}
+      %{start: %{line: 2, character: 6} = position} = range_from_markers(original)
 
       assert %{
-               start: %{line: 1, character: 6},
-               end: %{line: 1, character: 13}
+               start: %{line: 2, character: 6},
+               end: %{line: 2, character: 13}
+             } = range = Parser.position_to_range(original, position)
+
+      assert {
+               :ok,
+               %Sourceror.Zipper{},
+               {:do_bar?, _, nil}
+             } = Parser.parse_inputs(original, range)
+    end
+
+    test "parse the selected node when passed a position in the middle" do
+      original = """
+      defmodule Foo do
+        #    v
+        def do_bar?(arg) do
+        end
+      end
+      """
+
+      %{start: %{line: 2, character: 7} = position} = range_from_markers(original)
+
+      assert %{
+               start: %{line: 2, character: 6},
+               end: %{line: 2, character: 13}
+             } = range = Parser.position_to_range(original, position)
+
+      assert {
+               :ok,
+               %Sourceror.Zipper{},
+               {:do_bar?, _, nil}
+             } = Parser.parse_inputs(original, range)
+    end
+
+    test "parse the selected node when passed a position in the end" do
+      original = """
+      defmodule Foo do
+        #          v
+        def do_bar?(arg) do
+        end
+      end
+      """
+
+      %{start: %{line: 2, character: 13} = position} = range_from_markers(original)
+
+      assert %{
+               start: %{line: 2, character: 6},
+               end: %{line: 2, character: 13}
              } = range = Parser.position_to_range(original, position)
 
       assert {

test/refactorex_test.exs

@@ -224,7 +224,7 @@ defmodule RefactorexTest do
         jsonrpc: "2.0",
         params: %{
           textDocument: %{uri: file_uri},
-          position: %{line: 1, character: 5}
+          position: %{line: 1, character: 2}
         }
       })
 
@@ -245,7 +245,7 @@ defmodule RefactorexTest do
         params: %{
           newName: "bar",
           textDocument: %{uri: file_uri},
-          position: %{line: 1, character: 5}
+          position: %{line: 1, character: 2}
         }
       })