* SyntaxError constructor accepting extra arguments apart from message
is not as per ECMAScript standard. That one is Firefox/Mozilla specific
extension. We try to *add* properties, functions for extension - try not
to modify/extend standard defined functions, constructors.
* User can fileName, lineNumber and columnNumber of constructed
SyntaxError instance.
* On the java side, the NashornException and ScriptException's file,
line, column use the actual throw point from the script source. While
this can read the values from SyntaxError or any Error for that matter,
there is a problem. fileName, lineNumber, columnNumber could be set to
any value in script. These have to be converted to String, int, int
respectively. Conversion means calling [[DefaultValue]] with String,
Number hint - which is calling out to script code. This process can
itself throw exception!! All this may destroy info. on where exactly the
underlying exception was thrown.
* There is clear workaround. Script code can always read SyntaxError
instance's fileName, lineNumber etc. - which can be set to anything post
construction. Java code can get underling ECMA error instance via
NashornException.getEcmaError - which would return a ScriptObjectMirror.
Java code can call ScriptObjectMirror.getMember("fileName") etc. to
retrieve properties set by user's script.
Hope this helps,
-Sundar
On Wednesday 18 February 2015 08:29 PM, Tim Fox wrote:
Hi all,
I've started a new thread for this, so as not to clutter the previous
thread on exceptions.
I've come across a possible issue with creating SyntaxError objects
(and potentially other exceptions although I haven't tested them).
https://gist.github.com/purplefox/dfe30a38098c1708e24b
In the above gist I create a SyntaxError specifying message, fileName,
and lineNumber.
However fileName and lineNumber appear to be ignored, and instead the
SyntaxError fileName and lineNumber are set to the fileName of the
file where it was created and the lineNumber of the creation.
I'm not sure if I'm doing something wrong, but according to
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SyntaxError
I should be able to create SyntaxError objects like this.
There appears to be a further issue. If I then throw the syntax error
from the JS script, and catch it in Java like this:
try {
engine.eval(script);
} catch (ScriptException e) {
System.out.println("message:" + e.getMessage());
System.out.println("fileName:" + e.getFileName());
System.out.println("lineNumber:" + e.getLineNumber());
}
Then the message, fileName and lineNumber always correspond to place
where the object was created, not to the subsequently set values.
In other words, I can't figure out a way of creating a SyntaxError
object in JS with my own values of fileName and lineNumber and have
those values available in Java when caught.
Any ideas from the experts? :)
