[Fetch API] Implement Request.formData and Response.formData.

third_party/WebKit/Source/modules/fetch/Body.cpp

Index: third_party/WebKit/Source/modules/fetch/Body.cpp
diff --git a/third_party/WebKit/Source/modules/fetch/Body.cpp b/third_party/WebKit/Source/modules/fetch/Body.cpp
index 8d58b1c91185a77f9251cb88489166be20525677..8e94884ee95a09cbade23d92d6f7d360f09abcc9 100644
--- a/third_party/WebKit/Source/modules/fetch/Body.cpp
+++ b/third_party/WebKit/Source/modules/fetch/Body.cpp
@@ -12,9 +12,12 @@
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMTypedArray.h"
 #include "core/dom/ExecutionContext.h"
+#include "core/dom/URLSearchParams.h"
 #include "core/fileapi/Blob.h"
+#include "core/html/FormData.h"
 #include "modules/fetch/BodyStreamBuffer.h"
 #include "modules/fetch/FetchDataLoader.h"
+#include "platform/network/ParsedContentType.h"
 #include "platform/wtf/PassRefPtr.h"
 #include "platform/wtf/RefPtr.h"
 #include "public/platform/WebDataConsumerHandle.h"
@@ -72,6 +75,25 @@ class BodyArrayBufferConsumer final : public BodyConsumerBase {
   }
 };
 
+class BodyFormDataConsumer final : public BodyConsumerBase {
+  WTF_MAKE_NONCOPYABLE(BodyFormDataConsumer);
+
+ public:
+  explicit BodyFormDataConsumer(ScriptPromiseResolver* resolver)
+      : BodyConsumerBase(resolver) {}
+
+  void DidFetchDataLoadedFormData(FormData* formData) override {
+    Resolver()->Resolve(formData);
+  }
+
+  void DidFetchDataLoadedString(const String& string) override {
+    FormData* formData = FormData::Create();
+    for (const auto& pair : URLSearchParams::Create(string)->Params())
+      formData->append(pair.first, pair.second);
+    DidFetchDataLoadedFormData(formData);
+  }
+};
+
 class BodyTextConsumer final : public BodyConsumerBase {
   WTF_MAKE_NONCOPYABLE(BodyTextConsumer);
 
@@ -158,6 +180,46 @@ ScriptPromise Body::blob(ScriptState* script_state) {
   return promise;
 }
 
+ScriptPromise Body::formData(ScriptState* script_state) {
+  ScriptPromise promise = RejectInvalidConsumption(script_state);
+  if (!promise.IsEmpty())
+    return promise;
+
+  // See above comment.
+  if (!ExecutionContext::From(script_state))
+    return ScriptPromise();
+
+  ScriptPromiseResolver* resolver = ScriptPromiseResolver::Create(script_state);
+  const ParsedContentType parsedTypeWithParameters(ContentType());
+  const String parsedType = parsedTypeWithParameters.MimeType().LowerASCII();
+  promise = resolver->Promise();
+  if (parsedType == "multipart/form-data") {
+    const String boundary =
+        parsedTypeWithParameters.ParameterValueForName("boundary");
+    if (BodyBuffer() && !boundary.IsEmpty()) {
+      BodyBuffer()->StartLoading(
+          FetchDataLoader::CreateLoaderAsFormData(boundary),
+          new BodyFormDataConsumer(resolver));
+      return promise;
+    }
+  } else if (parsedType == "application/x-www-form-urlencoded") {
+    if (BodyBuffer()) {
+      BodyBuffer()->StartLoading(FetchDataLoader::CreateLoaderAsString(),
+                                 new BodyFormDataConsumer(resolver));
+    } else {
+      resolver->Resolve(FormData::Create());
+    }
+    return promise;
+  } else {
+    if (BodyBuffer())
+      BodyBuffer()->CloseAndLockAndDisturb();
+  }
+
+  resolver->Reject(V8ThrowException::CreateTypeError(script_state->GetIsolate(),

[horo, 2017/05/11 04:44:16]

Please update external/wpt/fetch/api/response/response-consume-empty.html and
external/wpt/fetch/api/response/response-consume-empty.html of LayoutTest.

According to the spec, formData() should throw a TypeError when the body is
empty.

[e_hakkinen, 2017/05/11 11:01:51]

Done.
Yes but only if content type is multipart/form-data.
In that case MultipartParser::Finish called by
FetchDataLoaderAsFormData::OnStateChange will fail and therefore OnStateChange
will call BodyConsumerBase::DidFetchDataLoadFailed which rejects a promise with
a TypeError.

[horo, 2017/05/12 08:43:02]

What I wanted to say was that these tests are incorrect.
So please change the tests.

[e_hakkinen, 2017/05/12 14:56:12]

Done. Upstream review with one LGTM is at
https://github.com/w3c/web-platform-tests/pull/5905 .

[horo, 2017/05/16 00:58:10]

Thank you!

+                                                     "Invalid MIME type"));
+  return promise;
+}
+
 ScriptPromise Body::json(ScriptState* script_state) {
   ScriptPromise promise = RejectInvalidConsumption(script_state);
   if (!promise.IsEmpty())