How to response non-latin characters in AWS lambda? - node.js

Question

Update Oct 12:
The issue is fixed now. See this post in aws forum for details.
I wrote a nodejs function simply respond with some Chinese characters. But it respond with wrong characters.
exports.handler = function(event, context) {
context.succeed('Hello 世界!');
};
The function result becomes:
"Hello ������������!"
I came across this problem when I wrote a function to parse some Chinese websites and retrieve their page titles. I manage to convert them into utf-8 (I used needle for the request), and console.log(title) correctly display those Chinese characters. But the result from context.succeed() shows up like the example above. What should I do to deal with these non-latin characters when responding the result?

Answer 1

From AWS Support (August 10, 2015):
Thank you for reaching out AWS Support with your question about
Lambda and UTF-8.
We are presently researching this issue as other customers have
brought this to our attention. There is no eta on when this will be
resolved or if this is something we can resolve.

Answer 2

As in AWS Documentation - Programming Model (Node.js):
Indicates the Lambda function execution and all callbacks completed
successfully. Here's the general syntax:
context.succeed (Object result);
where
Object result – provides the result of the function execution. The
result provided must be JSON.stringify compatible. This parameter is
optional. You can call this method without any parameters (succeed())
or pass a null value (succeed(null)). If AWS Lambda fails to stringify
or encounters another error, an unhandled error is thrown, with the
X-Amz-Function-Error response header set to Unhandled.
So, you can't get the result like this:
Hello 世界!
Because, the string Hello 世界! will be encoded as JSON. So, it will return:
"Hello 世界!"
If you see in the browser using AWS Lambda Console:
"Hello ������!"
Actually it's a valid JSON, you just need to decode it first and then process it.
Try to run this:
exports.handler = function (event, context) {
var jsonStr = JSON.stringify('Hello 世界!');
console.log(jsonStr);
console.log(JSON.parse(jsonStr));
context.succeed('Hello 世界!');
};
The log result will be:
2015-08-07T12:49:54.888Z 12345678-90ab-cdef-1234-567890abcdef "Hello 世界!"
2015-08-07T12:49:54.889Z 12345678-90ab-cdef-1234-567890abcdef Hello 世界!
After you decode it, you can get back your original string.