Reconcile reporting tests and boundaries

reporter_test.go

@@ -49,6 +49,31 @@ func TestReporterOutputSubmitsOnWrite(t *testing.T) {
 	}
 }
 
+type callerOwnedWriter struct {
+	bytes.Buffer
+	closeCalls int
+}
+
+func (w *callerOwnedWriter) Close() error {
+	w.closeCalls++
+	return nil
+}
+
+func TestReporterLeavesCallerWriterOpen(t *testing.T) {
+	destination := &callerOwnedWriter{}
+	reporter := newReporter(Streams{Out: destination})
+	_, _ = reporter.Output().Write([]byte("report"))
+	_ = reporter.RenderOutput(func(writer io.Writer) error {
+		_, err := io.WriteString(writer, " rendered")
+		return err
+	})
+	_ = reporter.finalize(Success(), nil)
+
+	if destination.String() != "report rendered" || destination.closeCalls != 0 {
+		t.Fatalf("destination = %q, Close calls = %d", destination.String(), destination.closeCalls)
+	}
+}
+
 func TestReporterQuietOutputDiscardsSuccessfully(t *testing.T) {
 	var destination bytes.Buffer
 	reporter := newReporter(Streams{Out: &destination})