Consider surround context until end whenever possible

Author: josevalim

lib/elixir/lib/code/fragment.ex

@@ -619,15 +619,15 @@ defmodule Code.Fragment do
     {reversed_pre, post} = adjust_position(reversed_pre, post)
 
     case take_identifier(post, []) do
-      {_, [], _} ->
+      :none ->
         maybe_operator(reversed_pre, post, line, opts)
 
       {:identifier, reversed_post, rest} ->
         {rest, _} = strip_spaces(rest, 0)
         reversed = reversed_post ++ reversed_pre
 
         case codepoint_cursor_context(reversed, opts) do
-          {{:struct, acc}, offset} ->
+          {{:struct, acc}, offset} when acc != [] ->
             build_surround({:struct, acc}, reversed, line, offset)
 
           {{:alias, acc}, offset} ->
@@ -729,15 +729,31 @@ defmodule Code.Fragment do
     do: take_identifier(t, [h | acc])
 
   defp take_identifier(rest, acc) do
-    with {[?. | t], _} <- strip_spaces(rest, 0),
+    {stripped, _} = strip_spaces(rest, 0)
+
+    with [?. | t] <- stripped,
          {[h | _], _} when h in ?A..?Z <- strip_spaces(t, 0) do
       take_alias(rest, acc)
     else
-      _ -> {:identifier, acc, rest}
+      # Consider it an identifier if we are at the end of line
+      # or if we have spaces not followed by . (call) or / (arity)
+      _ when acc == [] and (rest == [] or (hd(rest) in @space and hd(stripped) not in ~c"/.")) ->
+        {:identifier, acc, rest}
+
+      # If we are immediately followed by a container, we are still part of the identifier.
+      # We don't consider << as it _may_ be an operator.
+      _ when acc == [] and hd(stripped) in ~c"({[" ->
+        {:identifier, acc, rest}
+
+      _ when acc == [] ->
+        :none
+
+      _ ->
+        {:identifier, acc, rest}
     end
   end
 
-  defp take_alias([h | t], acc) when h not in @non_identifier,
+  defp take_alias([h | t], acc) when h in ?A..?Z or h in ?a..?z or h in ?0..9 or h == ?_,
     do: take_alias(t, [h | acc])
 
   defp take_alias(rest, acc) do

lib/elixir/test/elixir/code_fragment_test.exs

@@ -428,49 +428,50 @@ defmodule CodeFragmentTest do
     end
 
     test "column out of range" do
-      assert CF.surround_context("hello", {1, 20}) == :none
+      assert CF.surround_context("hello", {1, 20}) ==
+               %{begin: {1, 1}, context: {:local_or_var, ~c"hello"}, end: {1, 6}}
     end
 
     test "local_or_var" do
-      for i <- 1..8 do
+      for i <- 1..9 do
         assert CF.surround_context("hello_wo", {1, i}) == %{
                  context: {:local_or_var, ~c"hello_wo"},
                  begin: {1, 1},
                  end: {1, 9}
                }
       end
 
-      assert CF.surround_context("hello_wo", {1, 9}) == :none
+      assert CF.surround_context("hello_wo ", {1, 10}) == :none
 
-      for i <- 2..9 do
+      for i <- 2..10 do
         assert CF.surround_context(" hello_wo", {1, i}) == %{
                  context: {:local_or_var, ~c"hello_wo"},
                  begin: {1, 2},
                  end: {1, 10}
                }
       end
 
-      assert CF.surround_context(" hello_wo", {1, 10}) == :none
+      assert CF.surround_context(" hello_wo ", {1, 11}) == :none
 
-      for i <- 1..6 do
+      for i <- 1..7 do
         assert CF.surround_context("hello!", {1, i}) == %{
                  context: {:local_or_var, ~c"hello!"},
                  begin: {1, 1},
                  end: {1, 7}
                }
       end
 
-      assert CF.surround_context("hello!", {1, 7}) == :none
+      assert CF.surround_context("hello! ", {1, 8}) == :none
 
-      for i <- 1..5 do
+      for i <- 1..6 do
         assert CF.surround_context("안녕_세상", {1, i}) == %{
                  context: {:local_or_var, ~c"안녕_세상"},
                  begin: {1, 1},
                  end: {1, 6}
                }
       end
 
-      assert CF.surround_context("안녕_세상", {1, 6}) == :none
+      assert CF.surround_context("안녕_세상 ", {1, 6}) == :none
 
       # Keywords are not local or var
       for keyword <- ~w(do end after catch else rescue fn true false nil)c do
@@ -484,46 +485,77 @@ defmodule CodeFragmentTest do
       end
     end
 
-    test "local call" do
+    test "local + operator" do
       for i <- 1..8 do
+        assert CF.surround_context("hello_wo+", {1, i}) == %{
+                 context: {:local_or_var, ~c"hello_wo"},
+                 begin: {1, 1},
+                 end: {1, 9}
+               }
+      end
+
+      assert CF.surround_context("hello_wo+", {1, 9}) == %{
+               begin: {1, 9},
+               context: {:operator, ~c"+"},
+               end: {1, 10}
+             }
+
+      for i <- 1..9 do
+        assert CF.surround_context("hello_wo +", {1, i}) == %{
+                 context: {:local_or_var, ~c"hello_wo"},
+                 begin: {1, 1},
+                 end: {1, 9}
+               }
+      end
+
+      assert CF.surround_context("hello_wo +", {1, 10}) == %{
+               begin: {1, 10},
+               context: {:operator, ~c"+"},
+               end: {1, 11}
+             }
+    end
+
+    test "local call" do
+      for i <- 1..9 do
         assert CF.surround_context("hello_wo(", {1, i}) == %{
                  context: {:local_call, ~c"hello_wo"},
                  begin: {1, 1},
                  end: {1, 9}
                }
       end
 
-      assert CF.surround_context("hello_wo(", {1, 9}) == :none
+      assert CF.surround_context("hello_wo(", {1, 10}) == :none
 
-      for i <- 1..8 do
+      for i <- 1..9 do
         assert CF.surround_context("hello_wo (", {1, i}) == %{
                  context: {:local_call, ~c"hello_wo"},
                  begin: {1, 1},
                  end: {1, 9}
                }
       end
 
-      assert CF.surround_context("hello_wo (", {1, 9}) == :none
+      assert CF.surround_context("hello_wo (", {1, 10}) == :none
+      assert CF.surround_context("hello_wo (", {1, 11}) == :none
 
-      for i <- 1..6 do
+      for i <- 1..7 do
         assert CF.surround_context("hello!(", {1, i}) == %{
                  context: {:local_call, ~c"hello!"},
                  begin: {1, 1},
                  end: {1, 7}
                }
       end
 
-      assert CF.surround_context("hello!(", {1, 7}) == :none
+      assert CF.surround_context("hello!(", {1, 8}) == :none
 
-      for i <- 1..5 do
+      for i <- 1..6 do
         assert CF.surround_context("안녕_세상(", {1, i}) == %{
                  context: {:local_call, ~c"안녕_세상"},
                  begin: {1, 1},
                  end: {1, 6}
                }
       end
 
-      assert CF.surround_context("안녕_세상(", {1, 6}) == :none
+      assert CF.surround_context("안녕_세상(", {1, 7}) == :none
     end
 
     test "local arity" do
@@ -651,47 +683,47 @@ defmodule CodeFragmentTest do
     end
 
     test "alias" do
-      for i <- 1..8 do
+      for i <- 1..9 do
         assert CF.surround_context("HelloWor", {1, i}) == %{
                  context: {:alias, ~c"HelloWor"},
                  begin: {1, 1},
                  end: {1, 9}
                }
       end
 
-      assert CF.surround_context("HelloWor", {1, 9}) == :none
+      assert CF.surround_context("HelloWor ", {1, 10}) == :none
 
-      for i <- 2..9 do
+      for i <- 2..10 do
         assert CF.surround_context(" HelloWor", {1, i}) == %{
                  context: {:alias, ~c"HelloWor"},
                  begin: {1, 2},
                  end: {1, 10}
                }
       end
 
-      assert CF.surround_context(" HelloWor", {1, 10}) == :none
+      assert CF.surround_context(" HelloWor ", {1, 11}) == :none
 
-      for i <- 1..9 do
+      for i <- 1..10 do
         assert CF.surround_context("Hello.Wor", {1, i}) == %{
                  context: {:alias, ~c"Hello.Wor"},
                  begin: {1, 1},
                  end: {1, 10}
                }
       end
 
-      assert CF.surround_context("Hello.Wor", {1, 10}) == :none
+      assert CF.surround_context("Hello.Wor ", {1, 11}) == :none
 
-      for i <- 1..11 do
+      for i <- 1..12 do
         assert CF.surround_context("Hello . Wor", {1, i}) == %{
                  context: {:alias, ~c"Hello.Wor"},
                  begin: {1, 1},
                  end: {1, 12}
                }
       end
 
-      assert CF.surround_context("Hello . Wor", {1, 12}) == :none
+      assert CF.surround_context("Hello . Wor ", {1, 13}) == :none
 
-      for i <- 1..15 do
+      for i <- 1..16 do
         assert CF.surround_context("Foo . Bar . Baz", {1, i}) == %{
                  context: {:alias, ~c"Foo.Bar.Baz"},
                  begin: {1, 1},
@@ -858,15 +890,15 @@ defmodule CodeFragmentTest do
                end: {1, 15}
              }
 
-      for i <- 2..9 do
+      for i <- 2..10 do
         assert CF.surround_context("%HelloWor", {1, i}) == %{
                  context: {:struct, ~c"HelloWor"},
                  begin: {1, 1},
                  end: {1, 10}
                }
       end
 
-      assert CF.surround_context("%HelloWor", {1, 10}) == :none
+      assert CF.surround_context("%HelloWor ", {1, 11}) == :none
 
       # With dot
       assert CF.surround_context("%Hello.Wor", {1, 1}) == %{
@@ -875,15 +907,15 @@ defmodule CodeFragmentTest do
                end: {1, 11}
              }
 
-      for i <- 2..10 do
+      for i <- 2..11 do
         assert CF.surround_context("%Hello.Wor", {1, i}) == %{
                  context: {:struct, ~c"Hello.Wor"},
                  begin: {1, 1},
                  end: {1, 11}
                }
       end
 
-      assert CF.surround_context("%Hello.Wor", {1, 11}) == :none
+      assert CF.surround_context("%Hello.Wor ", {1, 12}) == :none
 
       # With spaces
       assert CF.surround_context("% Hello . Wor", {1, 1}) == %{
@@ -892,15 +924,15 @@ defmodule CodeFragmentTest do
                end: {1, 14}
              }
 
-      for i <- 2..13 do
+      for i <- 2..14 do
         assert CF.surround_context("% Hello . Wor", {1, i}) == %{
                  context: {:struct, ~c"Hello.Wor"},
                  begin: {1, 1},
                  end: {1, 14}
                }
       end
 
-      assert CF.surround_context("% Hello . Wor", {1, 14}) == :none
+      assert CF.surround_context("% Hello . Wor ", {1, 15}) == :none
     end
 
     test "module attributes" do