SQSEvent with JSON inside the message body

Question

I want to use SQS as a trigger to my .Net Core lambda function. The message body that is being sent in the SQS message contains a JSON object.  
When I try to test this both in Visual Studio and the test event in AWS Lambda, I get the following exception:

```
{
  "errorType": "JsonSerializerException",
  "errorMessage": "Error converting the Lambda event JSON payload to type Amazon.Lambda.SQSEvents.SQSEvent: Unexpected character encountered while parsing value: {. Path 'Records[0].body', line 1, position 111.",
  "stackTrace": [
    "at Amazon.Lambda.Serialization.Json.JsonSerializer.Deserialize[T](Stream requestStream)",
    "at lambda_method(Closure , Stream , Stream , LambdaContextInternal )"
  ],
  "cause": {
    "errorType": "JsonReaderException",
    "errorMessage": "Unexpected character encountered while parsing value: {. Path 'Records[0].body', line 1, position 111.",
    "stackTrace": [
      "at Newtonsoft.Json.JsonTextReader.ReadStringValue(ReadType readType)",
      "at Newtonsoft.Json.JsonTextReader.ReadAsString()",
      "at Newtonsoft.Json.JsonReader.ReadForType(JsonContract contract, Boolean hasConverter)",
      "at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)",
      "at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)",
      "at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateList(IList list, JsonReader reader, JsonArrayContract contract, JsonProperty containerProperty, String id)",
      "at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateList(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, Object existingValue, String id)",
      "at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.SetPropertyValue(JsonProperty property, JsonConverter propertyConverter, JsonContainerContract containerContract, JsonProperty containerProperty, JsonReader reader, Object target)",
      "at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)",
      "at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)",
      "at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)",
      "at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)",
      "at Newtonsoft.Json.JsonSerializer.Deserialize[T](JsonReader reader)",
      "at Amazon.Lambda.Serialization.Json.JsonSerializer.Deserialize[T](Stream requestStream)"
    ]
  }
}
```

-----  
  
My function handler's signature looks like this:

```
public async Task FunctionHandler(SQSEvent sqsEvent, ILambdaContext context)
```

-----  
  
My SQS Message event looks like this:

```
{
  "Records": [
    {
      "messageId": "19dd0b57-b21e-4ac1-bd88-01bbb068cb78",
      "receiptHandle": "MessageReceiptHandle",
      "body": "{  
                       "Message":"   {  
                            \"ApplicationReference\":2
                        }"
                     }",
      "attributes": {
        "ApproximateReceiveCount": "1",
        "SentTimestamp": "1523232000000",
        "SenderId": "123456789012",
        "ApproximateFirstReceiveTimestamp": "1523232000001"
      },
      "messageAttributes": {},
      "md5OfBody": "7b270e59b47ff90a553787216d55d91d",
      "eventSource": "aws:sqs",
      "eventSourceARN": "arn:aws:sqs:eu-west-1:156445482446:TestQueue",
      "awsRegion": "eu-west-1"
    }
  ]
}
```

-----  
  
However this seems to work when I let the lambda run, so it makes me think that this is an issue with how I'm escaping the JSON in my tests. Can anyone point me in the right direction? Ideally I'd like to be able to test my function before I upload it to production

Answer

You shouldn't have to escape the quotes. Try using the following test event in the Lambda Console:

```
{
  "Records": [
    {
      "messageId": "19dd0b57-b21e-4ac1-bd88-01bbb068cb78",
      "receiptHandle": "MessageReceiptHandle",
      "body": {  
            "Message":   {  
                "ApplicationReference": "2"
            }
        },
      "attributes": {
        "ApproximateReceiveCount": "1",
        "SentTimestamp": "1523232000000",
        "SenderId": "123456789012",
        "ApproximateFirstReceiveTimestamp": "1523232000001"
      },
      "messageAttributes": {},
      "md5OfBody": "7b270e59b47ff90a553787216d55d91d",
      "eventSource": "aws:sqs",
      "eventSourceARN": "arn:aws:sqs:us-west-2:123456789012:MyQueue",
      "awsRegion": "us-west-2"
    }
  ]
}
```

If you find you do need to escape, you can try the following instead:

```
"body": "{
  \"Message\": {
    \"ApplicationReference\": \"2\"
  }
}",
```

SQSEvent with JSON inside the message body

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