Improve Blob constructor error messages.

Source/bindings/v8/custom/V8BlobCustom.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "V8Blob.h"
 
 #include "bindings/v8/Dictionary.h"
+#include "bindings/v8/ExceptionMessages.h"
 #include "bindings/v8/V8Binding.h"
 #include "bindings/v8/V8Utilities.h"
 #include "bindings/v8/custom/V8ArrayBufferCustom.h"
 #include "bindings/v8/custom/V8ArrayBufferViewCustom.h"
 #include "core/fileapi/BlobBuilder.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
 void V8Blob::constructorCustom(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     if (!info.Length()) {
         RefPtr<Blob> blob = Blob::create();
         info.GetReturnValue().Set(toV8(blob.get(), info.Holder(), info.GetIsolate()));
         return;
     }
 
     uint32_t length = 0;
     if (info[0]->IsArray()) {
         length = v8::Local<v8::Array>::Cast(info[0])->Length();
     } else {
-        bool notASequence = false;
-        toV8Sequence(info[0], length, notASequence, info.GetIsolate());
-        if (notASequence) {
-            throwTypeError("First argument of the constructor is not of type Array", info.GetIsolate());
+        const int sequenceArgumentIndex = 0;
+        if (toV8Sequence(info[sequenceArgumentIndex], length, info.GetIsolate()).IsEmpty()) {
+            throwTypeError(ExceptionMessages::failedToConstruct("Blob", ExceptionMessages::notAnArrayTypeArgumentOrValue(sequenceArgumentIndex + 1)), info.GetIsolate());
             return;
         }
     }
 
     String type;
     String endings = "transparent";
 
     if (info.Length() > 1) {
         if (!info[1]->IsObject()) {
-            throwTypeError("Second argument of the constructor is not of type Object", info.GetIsolate());
+            throwTypeError(ExceptionMessages::failedToConstruct("Blob", "The 2nd argument is not of type Object."), info.GetIsolate());
             return;
         }
 
         V8TRYCATCH_VOID(Dictionary, dictionary, Dictionary(info[1], info.GetIsolate()));
 
         V8TRYCATCH_VOID(bool, containsEndings, dictionary.get("endings", endings));
         if (containsEndings) {
             if (endings != "transparent" && endings != "native") {
-                throwTypeError("The endings property must be either \"transparent\" or \"native\"", info.GetIsolate());
+                throwTypeError(ExceptionMessages::failedToConstruct("Blob", "The 2nd argument's \"endings\" property must be either \"transparent\" or \"native\"."), info.GetIsolate());
                 return;
             }
         }
 
         V8TRYCATCH_VOID(bool, containsType, dictionary.get("type", type));
         UNUSED_PARAM(containsType);
         if (!type.containsOnlyASCII()) {
-            throwError(v8SyntaxError, "type must consist of ASCII characters", info.GetIsolate());
+            throwError(v8SyntaxError, ExceptionMessages::failedToConstruct("Blob", "The 2nd argument's \"type\" property must consist of ASCII characters."), info.GetIsolate());
             return;
         }
         type = type.lower();
     }
 
     ASSERT(endings == "transparent" || endings == "native");
 
     BlobBuilder blobBuilder;
     v8::Local<v8::Object> blobParts = v8::Local<v8::Object>::Cast(info[0]);
     for (uint32_t i = 0; i < length; ++i) {
@@ skipping 15 matching lines @@
             V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(V8StringResource<>, stringValue, item);
             blobBuilder.append(stringValue, endings);
         }
     }
 
     RefPtr<Blob> blob = blobBuilder.getBlob(type);
     info.GetReturnValue().Set(toV8(blob.get(), info.Holder(), info.GetIsolate()));
 }
 
 } // namespace WebCore