Add :include_comments option to Ast.from/2

Use Sourceror.parse_string/1 when include_comments: true.

Author: robmckinnon

apps/language_server/lib/language_server/experimental/code_mod/ast.ex

@@ -10,15 +10,21 @@ defmodule ElixirLS.LanguageServer.Experimental.CodeMod.Ast do
           | {any(), any()}
           | {atom() | {any(), [any()], atom() | [any()]}, Keyword.t(), atom() | [any()]}
 
-  @spec from(source) :: t
-  def from(%SourceFile{} = source_file) do
+  def from(source_file, opts \\ [])
+
+  @spec from(source, keyword()) :: t
+  def from(%SourceFile{} = source_file, opts) do
     source_file
     |> SourceFile.to_string()
-    |> from()
+    |> from(opts)
   end
 
-  def from(s) when is_binary(s) do
-    ElixirSense.string_to_quoted(s, 1, 6, token_metadata: true)
+  def from(s, opts) when is_binary(s) do
+    if opts[:include_comments] do
+      Sourceror.parse_string(s)
+    else
+      ElixirSense.string_to_quoted(s, 1, 6, token_metadata: true)
+    end
   end
 
   @spec to_string(t()) :: String.t()

apps/language_server/test/experimental/code_mod/ast_test.exs

@@ -0,0 +1,86 @@
+defmodule ElixirLS.LanguageServer.Experimental.CodeMod.AstTest do
+  alias ElixirLS.LanguageServer.Experimental.CodeMod.Ast
+
+  use ExUnit.Case
+
+  describe "ast" do
+    test "from\2 / to_string\1" do
+      string = """
+      defmodule Bar do
+        def foo(baz) do
+          # TODO
+        end
+      end
+      """
+
+      {:ok, ast} = Ast.from(string, include_comments: true)
+      assert string == Ast.to_string(ast) <> "\n"
+
+      {:ok, ast_missing_comments} = Ast.from(string)
+
+      assert """
+             defmodule Bar do
+               def foo(baz) do
+               end
+             end
+             """ == Ast.to_string(ast_missing_comments) <> "\n"
+    end
+
+    test "from\1" do
+      assert {:ok,
+              {:def, [do: [line: 1, column: 16], end: [line: 3, column: 3], line: 1, column: 3],
+               [
+                 {:foo, [closing: [line: 1, column: 14], line: 1, column: 7],
+                  [{:baz, [line: 1, column: 11], nil}]},
+                 [do: {:__block__, [], []}]
+               ]}} =
+               Ast.from("""
+                 def foo(baz) do
+                   # TODO
+                 end
+               """)
+    end
+
+    test "from\2" do
+      assert {:ok,
+              {:def,
+               [
+                 trailing_comments: [
+                   %{column: 5, line: 2, next_eol_count: 1, previous_eol_count: 1, text: "# TODO"}
+                 ],
+                 leading_comments: [],
+                 do: [line: 1, column: 16],
+                 end: [line: 3, column: 3],
+                 line: 1,
+                 column: 3
+               ],
+               [
+                 {:foo,
+                  [
+                    trailing_comments: [],
+                    leading_comments: [],
+                    closing: [line: 1, column: 14],
+                    line: 1,
+                    column: 7
+                  ],
+                  [
+                    {:baz, [trailing_comments: [], leading_comments: [], line: 1, column: 11],
+                     nil}
+                  ]},
+                 [
+                   {{:__block__,
+                     [trailing_comments: [], leading_comments: [], line: 1, column: 16], [:do]},
+                    {:__block__, [trailing_comments: [], leading_comments: []], []}}
+                 ]
+               ]}} =
+               Ast.from(
+                 """
+                   def foo(baz) do
+                     # TODO
+                   end
+                 """,
+                 include_comments: true
+               )
+    end
+  end
+end