Submit a channelSid to this function and have it wrap-up or cancel the associated TaskRouter Task.

twilio-flex-wrap-or-cancel-chat-task.js

// view instructions about the twilio-flex-token-validator here: https://www.npmjs.com/package/twilio-flex-token-validator
const JWEValidator = require('twilio-flex-token-validator').functionValidator;

exports.handler = JWEValidator(async function(context, event, callback) {
      
    // setup twilio client
    const client = context.getTwilioClient();
    
    // parse data form the incoming http request
    const channelSid = event.channelSid;
    
    // setup a response object
    const response = new Twilio.Response();
    response.appendHeader('Access-Control-Allow-Origin', '*');
    response.appendHeader('Access-Control-Allow-Methods', 'OPTIONS POST');
    response.appendHeader('Content-Type', 'application/json');
    response.appendHeader('Access-Control-Allow-Headers', 'Content-Type');
    
    let task = await client.taskrouter.workspaces(context.TWILIO_WORKSPACE_SID).tasks.list({
        evaluateTaskAttributes: `channelSid == "${channelSid}"`,
        limit: 1
    });

    task = task[0];
    
    if (task.assignmentStatus == 'pending' || task.assignmentStatus == 'reserved') {
        await client.taskrouter.workspaces(context.TWILIO_WORKSPACE_SID).tasks(task.sid).update({
           assignmentStatus: 'canceled',
           reason: 'customer left chat'
        });
    }
    
    if (task.assignmentStatus == 'assigned') {
        await client.taskrouter.workspaces(context.TWILIO_WORKSPACE_SID).tasks(task.sid).update({
           assignmentStatus: 'wrapping'
        });
    }
                    
    response.setBody({
        status: 'success'
    });
    
    callback(null, response);
});