Make Code.Fragment.surround_context behave consistently with CRLF

lib/elixir/lib/code/fragment.ex

@@ -133,6 +133,7 @@ defmodule Code.Fragment do
   def cursor_context(fragment, opts \\ [])
 
   def cursor_context(binary, opts) when is_binary(binary) and is_list(opts) do
+    # CRLF not relevant here - we discard everything before last `\n`
     binary =
       case :binary.matches(binary, "\n") do
         [] ->
@@ -151,6 +152,7 @@ defmodule Code.Fragment do
   end
 
   def cursor_context(charlist, opts) when is_list(charlist) and is_list(opts) do
+    # CRLF not relevant here - we discard everything before last `\n`
     charlist =
       case charlist |> Enum.chunk_by(&(&1 == ?\n)) |> List.last([]) do
         [?\n | _] -> []
@@ -508,14 +510,16 @@ defmodule Code.Fragment do
 
   def surround_context(binary, {line, column}, opts) when is_binary(binary) do
     binary
-    |> String.split("\n")
+    |> String.split(["\r\n", "\n"])
     |> Enum.at(line - 1, '')
     |> String.to_charlist()
     |> position_surround_context(line, column, opts)
   end
 
   def surround_context(charlist, {line, column}, opts) when is_list(charlist) do
     charlist
+    |> :string.replace('\r\n', '\n', :all)
+    |> :string.join('')
     |> :string.split('\n', :all)
     |> Enum.at(line - 1, '')
     |> position_surround_context(line, column, opts)

lib/elixir/test/elixir/code_fragment_test.exs

@@ -20,6 +20,10 @@ defmodule CodeFragmentTest do
       assert CF.cursor_context('\n') == :expr
       assert CF.cursor_context("\n\n") == :expr
       assert CF.cursor_context('\n\n') == :expr
+      assert CF.cursor_context("\r\n") == :expr
+      assert CF.cursor_context('\r\n') == :expr
+      assert CF.cursor_context("\r\n\r\n") == :expr
+      assert CF.cursor_context('\r\n\r\n') == :expr
     end
 
     test "local_or_var" do
@@ -267,6 +271,8 @@ defmodule CodeFragmentTest do
     test "newlines" do
       assert CF.cursor_context("this+does-not*matter\nHello.") == {:dot, {:alias, 'Hello'}, ''}
       assert CF.cursor_context('this+does-not*matter\nHello.') == {:dot, {:alias, 'Hello'}, ''}
+      assert CF.cursor_context("this+does-not*matter\r\nHello.") == {:dot, {:alias, 'Hello'}, ''}
+      assert CF.cursor_context('this+does-not*matter\r\nHello.') == {:dot, {:alias, 'Hello'}, ''}
     end
   end
 
@@ -278,6 +284,18 @@ defmodule CodeFragmentTest do
                  begin: {3, 1},
                  end: {3, 9}
                }
+
+        assert CF.surround_context("\r\n\r\nhello_wo\r\n", {3, i}) == %{
+                 context: {:local_or_var, 'hello_wo'},
+                 begin: {3, 1},
+                 end: {3, 9}
+               }
+
+        assert CF.surround_context('\r\n\r\nhello_wo\r\n', {3, i}) == %{
+                 context: {:local_or_var, 'hello_wo'},
+                 begin: {3, 1},
+                 end: {3, 9}
+               }
       end
     end