The behavior on sending message-attributes with empty value is different from that of SQS

[ara-ta3]

When I send a message to sqs with empty value, sqs returns error (InvalidParameterValue).

cat attributes.json
{
  "piyo": {
    "DataType": "String",
    "StringValue": ""
  }
}
aws sqs send-message \
    --queue-url https://sqs.ap-northeast-1.amazonaws.com/XXXXXXXXXX/elastic-mq-debug \
    --message-body bar \
    --message-attributes file://attributes.json
An error occurred (InvalidParameterValue) when calling the SendMessage operation: Message (user) attribute 'piyo' must contain a non-empty value of type 'String'.

But elastmq does not return error.

 java -jar elasticmq-server-0.15.7.jar
...

aws --endpoint-url http://localhost:9324 sqs create-queue --queue-name foo
{
    "QueueUrl": "http://localhost:9324/queue/foo"
}
cat attributes.json
{
  "piyo": {
    "DataType": "String",
    "StringValue": ""
  }
}
aws --endpoint-url http://localhost:9324 \
    sqs send-message \
    --queue-url http://localhost:9324/queue/foo \
    --message-body bar \
    --message-attributes file://attributes.json
{
    "MD5OfMessageBody": "37b51d194a7513e45b56f6524f2d51f2",
    "MD5OfMessageAttributes": "4166cc16b73099be3abe8e2b0f544c99",
    "MessageId": "62aa4db3-9666-4421-a1d8-b988f76b7ae1"
}
echo $?
0

[adamw]

Fixed in 0.15.8