[modules] Improve error messages.

src/messages.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // The infrastructure used for (localized) message reporting in V8.
 //
 // Note: there's a big unresolved issue about ownership of the data
 // structures used by this framework.
 
 #ifndef V8_MESSAGES_H_
@@ skipping 502 matching lines @@
   T(NumberFormatRange, "% argument must be between 0 and 20")                  \
   T(PropertyValueOutOfRange, "% value is out of range.")                       \
   T(StackOverflow, "Maximum call stack size exceeded")                         \
   T(ToPrecisionFormatRange, "toPrecision() argument must be between 1 and 21") \
   T(ToRadixFormatRange, "toString() radix argument must be between 2 and 36")  \
   T(TypedArraySetNegativeOffset, "Start offset is negative")                   \
   T(TypedArraySetSourceTooLarge, "Source is too large")                        \
   T(UnsupportedTimeZone, "Unsupported time zone specified %")                  \
   T(ValueOutOfRange, "Value % out of range for % options property %")          \
   /* SyntaxError */                                                            \
-  T(AmbiguousExport, "Multiple star exports provide name '%'")                 \
+  T(AmbiguousExport,                                                           \
+    "The requested module contains conflicting star exports for name '%'")     \
   T(BadGetterArity, "Getter must not have any formal parameters.")             \
   T(BadSetterArity, "Setter must have exactly one formal parameter.")          \
   T(ConstructorIsAccessor, "Class constructor may not be an accessor")         \
   T(ConstructorIsGenerator, "Class constructor may not be a generator")        \
   T(ConstructorIsAsync, "Class constructor may not be an async method")        \
   T(DerivedConstructorReturn,                                                  \
     "Derived constructors may only return object or undefined")                \
   T(DuplicateConstructor, "A class may only have one constructor")             \
   T(DuplicateExport, "Duplicate export of '%'")                                \
   T(DuplicateProto,                                                            \
@@ skipping 84 matching lines @@
   T(UnexpectedStrictReserved, "Unexpected strict mode reserved word")          \
   T(UnexpectedSuper, "'super' keyword unexpected here")                        \
   T(UnexpectedNewTarget, "new.target expression is not allowed here")          \
   T(UnexpectedTemplateString, "Unexpected template string")                    \
   T(UnexpectedToken, "Unexpected token %")                                     \
   T(UnexpectedTokenIdentifier, "Unexpected identifier")                        \
   T(UnexpectedTokenNumber, "Unexpected number")                                \
   T(UnexpectedTokenString, "Unexpected string")                                \
   T(UnexpectedTokenRegExp, "Unexpected regular expression")                    \
   T(UnknownLabel, "Undefined label '%'")                                       \
-  T(UnresolvableExport, "Module does not provide an export named '%'")         \
+  T(UnresolvableExport,                                                        \
+    "The requested module does not provide an export named '%'")               \
   T(UnterminatedArgList, "missing ) after argument list")                      \
   T(UnterminatedRegExp, "Invalid regular expression: missing /")               \
   T(UnterminatedTemplate, "Unterminated template literal")                     \
   T(UnterminatedTemplateExpr, "Missing } in template expression")              \
   T(FoundNonCallableHasInstance, "Found non-callable @@hasInstance")           \
   T(InvalidHexEscapeSequence, "Invalid hexadecimal escape sequence")           \
   T(InvalidUnicodeEscapeSequence, "Invalid Unicode escape sequence")           \
   T(UndefinedUnicodeCodePoint, "Undefined Unicode code-point")                 \
   T(YieldInParameter, "Yield expression not allowed in formal parameter")      \
   /* EvalError */                                                              \
@@ skipping 63 matching lines @@
   static Handle<String> GetMessage(Isolate* isolate, Handle<Object> data);
   static std::unique_ptr<char[]> GetLocalizedMessage(Isolate* isolate,
                                                      Handle<Object> data);
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_MESSAGES_H_