Use a buffer for Ansi2html so it's not affecting Stream

Fixes https://sentry.gitlap.com/gitlab/gitlabcom/issues/27545/

Use a buffer for Ansi2html so it's not affecting Stream
Fixes https://sentry.gitlap.com/gitlab/gitlabcom/issues/27545/
7c1abc2c · Lin Jen-Shin · ec9f6180 · 7c1abc2c · 7c1abc2c
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -14,14 +14,7 @@ class Stream

        def initialize
          @stream = yield
-          if @stream
-            @stream.binmode
-            # Ci::Ansi2html::Converter would read from @stream directly,
-            # using @stream.each_line to be specific. It's safe to set
-            # the encoding here because IO#seek(bytes) and IO#read(bytes)
-            # are not characters based, so encoding doesn't matter to them.
-            @stream.set_encoding(Encoding.default_external)
-          end
+          @stream.binmode if @stream
        end

        def valid?
@@ -63,13 +56,14 @@ def raw(last_lines: nil)
        end

        def html_with_state(state = nil)
-          ::Ci::Ansi2html.convert(stream, state)
+          buffer = create_stream_for_ansi2html(stream) if stream
+          ::Ci::Ansi2html.convert(buffer, state)
        end

        def html(last_lines: nil)
          text = raw(last_lines: last_lines)
-          stream = StringIO.new(text)
-          ::Ci::Ansi2html.convert(stream).html
+          buffer = create_stream_for_ansi2html(text)
+          ::Ci::Ansi2html.convert(buffer).html
        end

        def extract_coverage(regex)
@@ -122,6 +116,24 @@ def read_last_lines(last_lines)

          chunks.join.lines.last(last_lines).join
        end
+
+        def create_stream_for_ansi2html(io_or_string)
+          buffer = StringIO.new
+
+          case io_or_string
+          when IO, StringIO
+            IO.copy_stream(io_or_string, buffer)
+          when String
+            buffer.string = io_or_string
+          else
+            raise TypeError,
+              "should be an IO or String, but got: #{io_or_string.class}"
+          end
+
+          buffer.set_encoding(Encoding.default_external)
+          buffer.rewind
+          buffer
+        end
      end
    end
  end

--- a/spec/lib/gitlab/ci/trace/stream_spec.rb
+++ b/spec/lib/gitlab/ci/trace/stream_spec.rb
@@ -71,9 +71,13 @@
  end

  describe '#append' do
+    let(:tempfile) { Tempfile.new }
+
    let(:stream) do
      described_class.new do
-        StringIO.new("12345678")
+        tempfile.write("12345678")
+        tempfile.rewind
+        tempfile
      end
    end

@@ -84,6 +88,17 @@
      expect(stream.size).to eq(6)
      expect(stream.raw).to eq("123489")
    end
+
+    it 'appends in binary mode' do
+      '😺'.force_encoding('ASCII-8BIT').each_char.with_index do |byte, offset|
+        stream.append(byte, offset)
+      end
+
+      stream.seek(0)
+
+      expect(stream.size).to eq(4)
+      expect(stream.raw).to eq('😺')
+    end
  end

  describe '#set' do