MHTMLTest::TestMHTMLEncoding checks generated MTHML is well formed.

third_party/WebKit/Source/web/tests/MHTMLTest.cpp

Index: third_party/WebKit/Source/web/tests/MHTMLTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/MHTMLTest.cpp b/third_party/WebKit/Source/web/tests/MHTMLTest.cpp
index 494f0713505ffc3e915dcbb684d4756014b7332f..c1790132c7378e375b8d4e80719ee5767c23d595 100644
--- a/third_party/WebKit/Source/web/tests/MHTMLTest.cpp
+++ b/third_party/WebKit/Source/web/tests/MHTMLTest.cpp
@@ -35,6 +35,7 @@
 #include "platform/SerializedResource.h"
 #include "platform/SharedBuffer.h"
 #include "platform/mhtml/MHTMLArchive.h"
+#include "platform/mhtml/MHTMLParser.h"
 #include "platform/testing/URLTestHelpers.h"
 #include "platform/testing/UnitTestHelpers.h"
 #include "platform/weborigin/KURL.h"
@@ -207,6 +208,10 @@ TEST_F(MHTMLTest, TestMHTMLEncoding) {
   RefPtr<RawData> data = Serialize("Test Serialization", "text/html",
                                    MHTMLArchive::kUseDefaultEncoding);
 
+  // Validate the generated MHTML.
+  MHTMLParser parser(SharedBuffer::Create(data->data(), data->length()));
+  ASSERT_FALSE(parser.ParseArchive().IsEmpty()) << "Invalid MHTML";

[Łukasz Anforowicz, 2017/04/25 19:01:24]

Would it be possible to increase the coverage of the new check by moving the
check to MHTMLTest::GenerateMHTMLData?  If some callers of
MHTMLTest::GenerateMHTMLData expect creation of malformed MHTML, then maybe we
can add a parameter to MHTMLTest::GenerateMHTMLData (or a field to MHTMLTest?)
that tells the code whether the asserts above are appropriate.

[carlosk, 2017/04/25 19:49:30]

Done.

+
   // Read the MHTML data line per line and do some pseudo-parsing to make sure
   // the right encoding is used for the different sections.
   LineReader line_reader(std::string(data->data(), data->length()));