Save data in conversation for dialogflow-fulfillment Node.js library

dialogflow-agent-data.js

// agent is an instance of WebhookClient
function setContextData(agent) {
  const handler = {
    set(target, property, value) {
      const parameters = agent.context.get("data")
        ? agent.context.get("data").parameters
        : {};

      parameters[property] = value;

      agent.context.set("data", 99, parameters);
    }
  };

  const obj = agent.context.get("data")
    ? agent.context.get("data").parameters
    : {};

  agent.data = new Proxy(obj, handler);

  return agent;
}

// This function must be used as a middleware
const agent = setContextData(new WebhookClient({ request, response }))

// Later on, we can make use of the data object
agent.data.count = 0 // -> will be available in the whole conversation