Consider start line in MismatchedDelimiterError

lib/elixir/lib/exception.ex

@@ -916,6 +916,7 @@ defmodule MismatchedDelimiterError do
     :file,
     :line,
     :column,
+    :line_offset,
     :end_line,
     :end_column,
     :opening_delimiter,
@@ -930,6 +931,7 @@ defmodule MismatchedDelimiterError do
         column: start_column,
         end_line: end_line,
         end_column: end_column,
+        line_offset: line_offset,
         description: description,
         opening_delimiter: opening_delimiter,
         closing_delimiter: _closing_delimiter,
@@ -941,13 +943,24 @@ defmodule MismatchedDelimiterError do
     lines = String.split(snippet, "\n")
     expected_delimiter = :elixir_tokenizer.terminator(opening_delimiter)
 
-    snippet = format_snippet(start_pos, end_pos, description, file, lines, expected_delimiter)
+    snippet =
+      format_snippet(
+        start_pos,
+        end_pos,
+        line_offset,
+        description,
+        file,
+        lines,
+        expected_delimiter
+      )
+
     format_message(file, end_line, end_column, snippet)
   end
 
   defp format_snippet(
          {start_line, _start_column} = start_pos,
          {end_line, end_column} = end_pos,
+         line_offset,
          description,
          file,
          lines,
@@ -960,12 +973,21 @@ defmodule MismatchedDelimiterError do
 
     relevant_lines =
       if end_line - start_line < @max_lines_shown do
-        line_range(lines, start_pos, end_pos, padding, max_digits, expected_delimiter)
+        line_range(
+          lines,
+          start_pos,
+          end_pos,
+          line_offset,
+          padding,
+          max_digits,
+          expected_delimiter
+        )
       else
         trimmed_inbetween_lines(
           lines,
           start_pos,
           end_pos,
+          line_offset,
           padding,
           max_digits,
           expected_delimiter
@@ -984,6 +1006,7 @@ defmodule MismatchedDelimiterError do
   defp format_snippet(
          {start_line, start_column},
          {end_line, end_column},
+         line_offset,
          description,
          file,
          lines,
@@ -994,7 +1017,7 @@ defmodule MismatchedDelimiterError do
     general_padding = max(2, max_digits) + 1
     padding = n_spaces(general_padding)
 
-    line = Enum.fetch!(lines, end_line - 1)
+    line = Enum.fetch!(lines, end_line - 1 - line_offset)
     formatted_line = [line_padding(end_line, max_digits), to_string(end_line), " │ ", line]
 
     mismatched_closing_line =
@@ -1042,14 +1065,15 @@ defmodule MismatchedDelimiterError do
          lines,
          {start_line, start_column},
          {end_line, end_column},
+         line_offset,
          padding,
          max_digits,
          expected_delimiter
        ) do
     start_padding = line_padding(start_line, max_digits)
     end_padding = line_padding(end_line, max_digits)
-    first_line = Enum.fetch!(lines, start_line - 1)
-    last_line = Enum.fetch!(lines, end_line - 1)
+    first_line = Enum.fetch!(lines, start_line - 1 - line_offset)
+    last_line = Enum.fetch!(lines, end_line - 1 - line_offset)
 
     """
     #{start_padding}#{start_line} │ #{first_line}
@@ -1064,6 +1088,7 @@ defmodule MismatchedDelimiterError do
          lines,
          {start_line, start_column},
          {end_line, end_column},
+         line_offset,
          padding,
          max_digits,
          expected_delimiter
@@ -1072,7 +1097,7 @@ defmodule MismatchedDelimiterError do
     end_line = end_line - 1
 
     lines
-    |> Enum.slice(start_line..end_line)
+    |> Enum.slice((start_line - line_offset)..(end_line - line_offset))
     |> Enum.zip_with(start_line..end_line, fn line, line_number ->
       line_number = line_number + 1
       start_line = start_line + 1

lib/elixir/src/elixir_errors.erl

@@ -404,9 +404,10 @@ parse_erl_term(Term) ->
   Parsed.
 
 raise_mismatched_delimiter(Location, File, Input, Message) ->
-  {InputString, _, _} = Input,
+  {InputString, StartLine, _} = Input,
   InputBinary = elixir_utils:characters_to_binary(InputString),
-  raise('Elixir.MismatchedDelimiterError', Message,  [{file, File}, {snippet, InputBinary} | Location]).
+  KV = [{file, File}, {line_offset, StartLine - 1}, {snippet, InputBinary} | Location],
+  raise('Elixir.MismatchedDelimiterError', Message, KV).
 
 raise_reserved(Location, File, Input, Keyword) ->
   raise_snippet(Location, File, Input, 'Elixir.SyntaxError',

lib/elixir/test/elixir/kernel/diagnostics_test.exs

@@ -53,6 +53,28 @@ defmodule Kernel.DiagnosticsTest do
              """
     end
 
+    test "same line with offset" do
+      output =
+        capture_raise(
+          """
+          [1, 2, 3, 4, 5, 6)
+          """,
+          MismatchedDelimiterError,
+          line: 3
+        )
+
+      assert output == """
+             ** (MismatchedDelimiterError) mismatched delimiter found on nofile:3:18:
+                 error: unexpected token: )
+                 │
+               3 │ [1, 2, 3, 4, 5, 6)
+                 │ │                └ mismatched closing delimiter (expected "]")
+                 │ └ unclosed delimiter
+                 │
+                 └─ nofile:3:18\
+             """
+    end
+
     test "two-line span" do
       output =
         capture_raise(
@@ -76,6 +98,30 @@ defmodule Kernel.DiagnosticsTest do
              """
     end
 
+    test "two-line span with offset" do
+      output =
+        capture_raise(
+          """
+          [a, b, c
+           d, f, g}
+          """,
+          MismatchedDelimiterError,
+          line: 3
+        )
+
+      assert output == """
+             ** (MismatchedDelimiterError) mismatched delimiter found on nofile:4:9:
+                 error: unexpected token: }
+                 │
+               3 │ [a, b, c
+                 │ └ unclosed delimiter
+               4 │  d, f, g}
+                 │         └ mismatched closing delimiter (expected "]")
+                 │
+                 └─ nofile:4:9\
+             """
+    end
+
     test "many-line span" do
       output =
         capture_raise(
@@ -103,28 +149,31 @@ defmodule Kernel.DiagnosticsTest do
                  │
                  └─ nofile:5:5\
              """
+    end
 
+    test "many-line span with offset" do
       output =
         capture_raise(
           """
           fn always_forget_end ->
             IO.inspect(2 + 2) + 2
           )
           """,
-          MismatchedDelimiterError
+          MismatchedDelimiterError,
+          line: 3
         )
 
       assert output == """
-             ** (MismatchedDelimiterError) mismatched delimiter found on nofile:3:1:
+             ** (MismatchedDelimiterError) mismatched delimiter found on nofile:5:1:
                  error: unexpected token: )
                  │
-               1 │ fn always_forget_end ->
+               3 │ fn always_forget_end ->
                  │ └ unclosed delimiter
-               2 │   IO.inspect(2 + 2) + 2
-               3 │ )
+               4 │   IO.inspect(2 + 2) + 2
+               5 │ )
                  │ └ mismatched closing delimiter (expected "end")
                  │
-                 └─ nofile:3:1\
+                 └─ nofile:5:1\
              """
     end
 
@@ -290,16 +339,6 @@ defmodule Kernel.DiagnosticsTest do
 
   describe "compile-time exceptions" do
     test "SyntaxError (snippet)" do
-      expected = """
-      ** (SyntaxError) invalid syntax found on nofile:1:17:
-          error: syntax error before: '*'
-          │
-        1 │ [1, 2, 3, 4, 5, *]
-          │                 ^
-          │
-          └─ nofile:1:17\
-      """
-
       output =
         capture_raise(
           """
@@ -308,20 +347,39 @@ defmodule Kernel.DiagnosticsTest do
           SyntaxError
         )
 
-      assert output == expected
+      assert output == """
+             ** (SyntaxError) invalid syntax found on nofile:1:17:
+                 error: syntax error before: '*'
+                 │
+               1 │ [1, 2, 3, 4, 5, *]
+                 │                 ^
+                 │
+                 └─ nofile:1:17\
+             """
     end
 
-    test "TokenMissingError (snippet)" do
-      expected = """
-      ** (TokenMissingError) token missing on nofile:1:4:
-          error: syntax error: expression is incomplete
-          │
-        1 │ 1 +
-          │    ^
-          │
-          └─ nofile:1:4\
-      """
+    test "SyntaxError (snippet) with offset" do
+      output =
+        capture_raise(
+          """
+          [1, 2, 3, 4, 5, *]
+          """,
+          SyntaxError,
+          line: 3
+        )
+
+      assert output == """
+             ** (SyntaxError) invalid syntax found on nofile:3:17:
+                 error: syntax error before: '*'
+                 │
+               3 │ [1, 2, 3, 4, 5, *]
+                 │                 ^
+                 │
+                 └─ nofile:3:17\
+             """
+    end
 
+    test "TokenMissingError (snippet)" do
       output =
         capture_raise(
           """
@@ -330,7 +388,36 @@ defmodule Kernel.DiagnosticsTest do
           TokenMissingError
         )
 
-      assert output == expected
+      assert output == """
+             ** (TokenMissingError) token missing on nofile:1:4:
+                 error: syntax error: expression is incomplete
+                 │
+               1 │ 1 +
+                 │    ^
+                 │
+                 └─ nofile:1:4\
+             """
+    end
+
+    test "TokenMissingError (snippet) with offset" do
+      output =
+        capture_raise(
+          """
+          1 +
+          """,
+          TokenMissingError,
+          line: 3
+        )
+
+      assert output == """
+             ** (TokenMissingError) token missing on nofile:3:4:
+                 error: syntax error: expression is incomplete
+                 │
+               3 │ 1 +
+                 │    ^
+                 │
+                 └─ nofile:3:4\
+             """
     end
 
     test "TokenMissingError (no snippet)" do
@@ -419,7 +506,7 @@ defmodule Kernel.DiagnosticsTest do
           1 -
           """,
           TokenMissingError,
-          fake_stacktrace
+          stacktrace: fake_stacktrace
         )
 
       assert output == expected
@@ -448,7 +535,7 @@ defmodule Kernel.DiagnosticsTest do
           1 -
           """,
           TokenMissingError,
-          fake_stacktrace
+          stacktrace: fake_stacktrace
         )
 
       assert output == expected
@@ -1104,14 +1191,16 @@ defmodule Kernel.DiagnosticsTest do
     end)
   end
 
-  defp capture_raise(source, exception, mock_stacktrace \\ []) do
+  defp capture_raise(source, exception, opts \\ []) do
+    {stacktrace, opts} = Keyword.pop(opts, :stacktrace, [])
+
     e =
       assert_raise exception, fn ->
-        ast = Code.string_to_quoted!(source, columns: true)
+        ast = Code.string_to_quoted!(source, [columns: true] ++ opts)
         Code.eval_quoted(ast)
       end
 
-    Exception.format(:error, e, mock_stacktrace)
+    Exception.format(:error, e, stacktrace)
   end
 
   defp purge(module) when is_atom(module) do