new ListSerializer<StyledTextOutputEvent.Span>(
                new SpanSerializer(serializerFactory.getSerializerFor(StyledTextOutput.Style.class))))
    }

    def "can serialize StyledTextOutputEvent messages"() {
        given:
        List spans = [new StyledTextOutputEvent.Span(StyledTextOutput.Style.Description, "description"),
                      new StyledTextOutputEvent.Span(StyledTextOutput.Style.Error, "error")]

    public void setText(String text) {
        this.spans = Collections.singletonList(new StyledTextOutputEvent.Span(text));
    }

    @Override
    public void setText(StyledTextOutputEvent.Span span) {
        this.spans = Collections.singletonList(span);
    }

    @Override
    public void setText(List<StyledTextOutputEvent.Span> spans) {
        this.spans = spans;
    }

    public Cursor getWritePosition() {

    }

    @Override
    void setText(StyledTextOutputEvent.Span span) {
        throw new UnsupportedOperationException()
    }

    @Override
    void setText(List<StyledTextOutputEvent.Span> spans) {
        String text = ""
        for (StyledTextOutputEvent.Span span : spans) {
            stringToStyleMap.put(span.text, span.style)
            text += span.text
        }
        setText(text)
    }

	// unswept set and pushes spans that are still in-use on the
	// swept set. Likewise, allocating an in-use span pushes it
	// on the swept set.
	//
	// Some parts of the sweeper can sweep arbitrary spans, and hence
	// can't remove them from the unswept set, but will add the span
	// to the appropriate swept list. As a result, the parts of the
	// sweeper and mcentral that do consume from the unswept list may

            event.spans.size() == 1 && event.spans[0].text == toNative('task2\n')
        })
        1 * target.onOutput({ StyledTextOutputEvent event ->
            event.spans.size() == 3 &&
                event.spans[0].text == toNative('task1 ') &&
                event.spans[1].text == toNative('task1-done') &&
                event.spans[2].text == toNative('\n')
        })

			scopes.Framework.Debugf("cannot parse or cannot find spans in trace object %+v", t)
			continue
		}
		var spans []Span
		for _, obj := range spanObjs {
			newSpan := buildSpan(obj)
			spans = append(spans, newSpan)
		}
		for p := range spans {
			for c := range spans {
				if spans[c].ParentSpanID == spans[p].SpanID {
					spans[p].ChildSpans = append(spans[p].ChildSpans, &spans[c])
				}
			}

        for (Span span : spans) {
            output.style(span.style);
            output.text(span.text);
        }
    }

    @Override
    public LogEventLevel getLevel() {
        return LogLevelConverter.convert(getLogLevel());
    }

    public static class Span implements org.gradle.internal.logging.events.operations.StyledTextBuildOperationProgressDetails.Span {
        private final String text;

        then:
        1 * listener.onOutput(!null) >> { args ->
            def event = args[0]
            assert event.spans.size() == 2
            assert event.spans[0].style == Header
            assert event.spans[0].text == 'header'
            assert event.spans[1].style == Normal
            assert event.spans[1].text == toNative('normal\n')
        }
        0 * listener._
    }

    def ignoresEmptySpans() {

        buffer.append(endOfLine);
        spans.add(new StyledTextOutputEvent.Span(this.style, buffer.toString()));
        buffer.setLength(0);
        OperationIdentifier buildOperationId = CurrentBuildOperationRef.instance().getId();
        listener.onOutput(new StyledTextOutputEvent(clock.getCurrentTime(), category, logLevel, buildOperationId, spans));
        spans = new ArrayList<StyledTextOutputEvent.Span>();
    }

issue:
  - 28801

releaseNotes:
- |
  **Added** canonical service tags to Envoy-generated trace spans.
upgradeNotes:
  - title: Service Tags added to trace spans
    content: |
      Istio now configures Envoy to include tags identifying the canonical service for a workload in generated trace spans.

      This will lead to a small increase in storage per span for tracing backends.