fixes #132

lib/csv/decoding/decoder.ex

@@ -22,7 +22,7 @@ defmodule CSV.Decoding.Decoder do
       Must be a codepoint (syntax: ? + (your separator)).
   * `:escape_character`    – The escape character token to use, defaults to `?"`.
       Must be a codepoint (syntax: ? + (your escape character)).
-  * `:escape_max_lines`    – The number of lines an escape sequence is allowed 
+  * `:escape_max_lines`    – The number of lines an escape sequence is allowed
       to span, defaults to 10.
   * `:field_transform`     – A function with arity 1 that will get called with
       each field and can apply transformations. Defaults to identity function.

lib/csv/decoding/parser.ex

@@ -19,11 +19,11 @@ defmodule CSV.Decoding.Parser do
 
   * `:separator`           – The separator token to use, defaults to `?,`.
       Must be a codepoint (syntax: ? + (your separator)).
-  * `:field_transform`     – A function with arity 1 that will get called with 
+  * `:field_transform`     – A function with arity 1 that will get called with
       each field and can apply transformations. Defaults to identity function.
-      This function will get called for every field and therefore should return 
+      This function will get called for every field and therefore should return
       quickly.
-  * `:unescape_formulas`   – When set to `true`, will remove formula escaping 
+  * `:unescape_formulas`   – When set to `true`, will remove formula escaping
       inserted to prevent [CSV Injection](https://owasp.org/www-community/attacks/CSV_Injection).
 
   ## Examples
@@ -167,7 +167,8 @@ defmodule CSV.Decoding.Parser do
           {[], {fields, partial_field, parse_state, sequence}},
           escape_character,
           token_pattern,
-          field_transform
+          field_transform,
+          sequence
         )
 
       sequence, {fields, partial_field, parse_state, {leftover_state, leftover_sequence}} ->
@@ -190,16 +191,17 @@ defmodule CSV.Decoding.Parser do
     end
   end
 
-  @compile {:inline, parse_to_end: 4}
-  defp parse_to_end({rows, {[], _, _, {_, ""}} = parse_state}, _, _, _) do
+  @compile {:inline, parse_to_end: 5}
+  defp parse_to_end({rows, {[], _, _, {_, ""}} = parse_state}, _, _, _, _) do
     {rows |> add_stream_halted_to_errors, parse_state}
   end
 
   defp parse_to_end(
          {rows, {fields, partial_field, {:open, _, _} = parse_state, {_, sequence}}},
          escape_character,
          token_pattern,
-         field_transform
+         field_transform,
+         _
        ) do
     tokens = :binary.matches(sequence, token_pattern)
 
@@ -220,7 +222,7 @@ defmodule CSV.Decoding.Parser do
           {escape_character, :binary.matches(sequence, @newline) |> Enum.count()},
           field_transform
         )
-        |> parse_to_end(escape_character, token_pattern, field_transform)
+        |> parse_to_end(escape_character, token_pattern, field_transform, sequence)
     end
   end
 
@@ -231,7 +233,8 @@ defmodule CSV.Decoding.Parser do
            {_, sequence}}},
          _,
          _,
-         field_transform
+         field_transform,
+         _
        ) do
     case byte_size(sequence) - 1 do
       ^previous_token_position ->
@@ -255,11 +258,27 @@ defmodule CSV.Decoding.Parser do
     end
   end
 
+  defp parse_to_end(
+    {rows, {_, _, {:escaped, _, _, line}, {_, sequence}}},
+    _,
+    _,
+    _,
+    last_sequence
+  ) when sequence == last_sequence do
+    {rows
+    |> add_error(StrayEscapeCharacterError,
+      line: line,
+      sequence: sequence,
+      stream_halted: true
+    ), empty_transform_state()}
+  end
+
   defp parse_to_end(
          {rows, {fields, partial_field, {:escaped, _, _, line} = parse_state, {_, sequence}}},
          escape_character,
          token_pattern,
-         field_transform
+         field_transform,
+         _
        ) do
     tokens = :binary.matches(sequence, token_pattern)
 
@@ -287,14 +306,15 @@ defmodule CSV.Decoding.Parser do
           {escape_character, :binary.matches(sequence, @newline) |> Enum.count()},
           field_transform
         )
-        |> parse_to_end(escape_character, token_pattern, field_transform)
+        |> parse_to_end(escape_character, token_pattern, field_transform, sequence)
     end
   end
 
   defp parse_to_end(
          {rows, {[], _, {:errored, _, error_module, construct_arguments, _}, _}},
          _,
          _,
+         _,
          _
        ) do
     {rows

test/decoding/parser_exceptions_test.exs

@@ -65,6 +65,16 @@ defmodule DecodingTests.ParserExceptionsTest do
     end)
   end
 
+  test "includes an error for rows with unescaped quotes and no newline" do
+    errors = Parser.parse(["a,b\n", "c,\"d,e"]) |> Enum.to_list()
+
+    assert errors == [
+             {:ok, ["a", "b"]},
+             {:error, CSV.StrayEscapeCharacterError,
+             [line: 2, sequence: "d,e", stream_halted: true]}
+           ]
+  end
+
   test "includes an error for rows with unescaped quotes in escape sequences on the same line" do
     stream = ["a,\"b\"e", "\"c,\"d", "\"e,f\"g\",h", "j,k"] |> to_line_stream
     errors = stream |> Parser.parse() |> Enum.to_list()