JsonReaderException when deserializing Slack payload to the InteractionPayload model

Version

Microsoft.Bot.Builder 4.10.3

Describe the bug

JsonReaderException when deserializing Slack payload to the InteractionPayload model.

Problem: Newtonsoft.Json.JsonReaderException at Newtonsoft.Json.JsonTextReader.ReadStringValue Message: Unexpected character encountered while parsing value: {. Path ‘state’, line 1, position 4505.

i.e. exception is thrown when a user selects an option from the Slack static select element.

Slack sends a dictionary of objects on state property and the Slack adapter library is trying to deserialize to a string. Slack API reference: https://api.slack.com/reference/interaction-payloads/block-actions#fields Microsoft.Bot.Builder.Adapters.Slack.Model.InteractionPayload class has the State property as a string property.

To Reproduce

1. Create a chatbot project using the Microsoft.Bot.Builder.Adapters.Slack.SlackAdapter
2. Configure the Slack app: set the Interactivity request URL to your chatbot endpoint
3. Post a message to Slack using the StaticSelectElement
4. Select an option from the select element
5. See the error happening on adapter.ProcessAsync

Expected behavior

Deserialize the model properly and send the activity to the ActivityHandler

[v-kydela]

@gabemilani - I have reproduced the error and I’m working on a fix

[gabemilani]

Here is a example:

var blocks = new List<IBlock>()
{
    new SectionBlock
    {
        text = new Text
        {
            type = "mrkdwn",
            text = "Select a fruit"
        }
    },
    new ActionsBlock() 
    {
        elements = new [] 
        { 
            new StaticSelectElement
            {
                placeholder = new Text { type = "plain_text", text = "Fruit" },
                action_id = "select-fruit",
                options = new [] {
                    new Option
                    {
                        text = new Text { type = "plain_text", text = "Apple" },
                        value = "select-fruit|apple"
                    },
                    new Option
                    {
                        text = new Text { type = "plain_text", text = "Orange" },
                        value = "select-fruit|orange"
                    }
                }
            }
        }
    }
};

Send a post request to the following API URL https://api.slack.com/methods/chat.postMessage#arg_blocks with that blocks payload