Azure Functions Http trigger - DocumentDB out Integration Microsoft.Azure.Documents.Client: Value cannot be null

Question

I'm trying to add a document to my DocumentDB with the incoming payloads to an HttpTriggered Azure Function. This is the function.json content:

{
"bindings": [
    {
      "authLevel": "function",
      "type": "httpTrigger",
      "direction": "in",
      "name": "req"
    },
    {
      "type": "http",
      "direction": "out",
      "name": "res"
    },
    {
      "type": "documentDB",
      "name": "email",
      "databaseName": "crawler",
      "collectionName": "SendGrid",
      "createIfNotExists": true,
      "connection": "noho_DOCUMENTDB",
      "direction": "out"
    }
  ],
  "disabled": false
}

And this is my function:

module.exports = function (context, req) {
try{
    if (req.body) {
        context.bindings.email = req.body;
        context.res = {
            status: 200,
            body: req.body
        };
    }
    else {
        context.res = {
            status: 400,
            body: "Please pass a name on the query string or in the request body"
        };
    }
} catch(e) {
    context.log(e);
    context.res = {
        status: 500,
        body: e
    };
}

context.done();
return req.body; 
};

It fails and throws an exception while processing an input POST request with the following message:

Exception while executing function: Functions.SendGridJs.

Microsoft.Azure.Documents.Client: Value cannot be null.

Parameter name: document.

I've setup the integration through the Azure Function integration wizard and not through code deployment. So, I'm assuming that Azure is taking care of the setup code.

Aaron Chen Aaron Chen · Accepted Answer · 2017-07-25T05:52:54

Both of your function.json and code of index.js are OK. You need to feed valid JSON string into req.body.

Here is my testing screenshot.

If I specify invalid JSON in the request body, I will get the same error as yours.

Azure Functions Http trigger - DocumentDB out Integration Microsoft.Azure.Documents.Client: Value cannot be null

1 Answers