Bug 889016 - Part 1: Add an API to report a not-enough-arguments error in Web IDL bindings; r=bzbarsky

dom/bindings/BindingUtils.cpp

@@ -23,6 +23,7 @@
 #include "xpcprivate.h"
 #include "XPCQuickStubs.h"
 #include "XrayWrapper.h"
+#include "nsPrintfCString.h"
 
 #include "mozilla/dom/HTMLObjectElement.h"
 #include "mozilla/dom/HTMLObjectElementBinding.h"
@@ -196,6 +197,17 @@ ErrorResult::StealJSException(JSContext* cx,
   mResult = NS_OK;
 }
 
+void
+ErrorResult::ReportNotEnoughArgsError(JSContext* cx,
+                                      const char* ifaceName,
+                                      const char* memberName)
+{
+  MOZ_ASSERT(ErrorCode() == NS_ERROR_XPC_NOT_ENOUGH_ARGS);
+
+  nsPrintfCString errorMessage("%s.%s", ifaceName, memberName);
+  ThrowErrorMessage(cx, dom::MSG_MISSING_ARGUMENTS, errorMessage.get());
+}
+
 namespace dom {
 
 bool

dom/bindings/BindingUtils.h

@@ -84,8 +84,8 @@ Throw(JSContext* cx, nsresult rv)
 template<bool mainThread>
 inline bool
 ThrowMethodFailedWithDetails(JSContext* cx, ErrorResult& rv,
-                             const char* /* ifaceName */,
-                             const char* /* memberName */)
+                             const char* ifaceName,
+                             const char* memberName)
 {
   if (rv.IsTypeError()) {
     rv.ReportTypeError(cx);
@@ -95,6 +95,9 @@ ThrowMethodFailedWithDetails(JSContext* cx, ErrorResult& rv,
     rv.ReportJSException(cx);
     return false;
   }
+  if (rv.IsNotEnoughArgsError()) {
+    rv.ReportNotEnoughArgsError(cx, ifaceName, memberName);
+  }
   return Throw<mainThread>(cx, rv.ErrorCode());
 }
 

dom/bindings/ErrorResult.h

@@ -53,6 +53,8 @@ public:
     MOZ_ASSERT(!IsTypeError(), "Don't overwite TypeError");
     MOZ_ASSERT(rv != NS_ERROR_DOM_JS_EXCEPTION, "Use ThrowJSException()");
     MOZ_ASSERT(!IsJSException(), "Don't overwrite JS exceptions");
+    MOZ_ASSERT(rv != NS_ERROR_XPC_NOT_ENOUGH_ARGS, "Use ThrowNotEnoughArgsError()");
+    MOZ_ASSERT(!IsNotEnoughArgsError(), "Don't overwrite not enough args error");
     mResult = rv;
   }
 
@@ -71,6 +73,12 @@ public:
   void ReportJSException(JSContext* cx);
   bool IsJSException() const { return ErrorCode() == NS_ERROR_DOM_JS_EXCEPTION; }
 
+  void ThrowNotEnoughArgsError() { mResult = NS_ERROR_XPC_NOT_ENOUGH_ARGS; }
+  void ReportNotEnoughArgsError(JSContext* cx,
+                                const char* ifaceName,
+                                const char* memberName);
+  bool IsNotEnoughArgsError() const { return ErrorCode() == NS_ERROR_XPC_NOT_ENOUGH_ARGS; }
+
   // StealJSException steals the JS Exception from the object. This method must
   // be called only if IsJSException() returns true. This method also resets the
   // ErrorCode() to NS_OK.
@@ -101,6 +109,8 @@ public:
     MOZ_ASSERT(!IsTypeError(), "Don't overwite TypeError");
     MOZ_ASSERT(rv != NS_ERROR_DOM_JS_EXCEPTION, "Use ThrowJSException()");
     MOZ_ASSERT(!IsJSException(), "Don't overwrite JS exceptions");
+    MOZ_ASSERT(rv != NS_ERROR_XPC_NOT_ENOUGH_ARGS, "Use ThrowNotEnoughArgsError()");
+    MOZ_ASSERT(!IsNotEnoughArgsError(), "Don't overwrite not enough args error");
     mResult = rv;
   }