How to add delay to all responses

I would like to test user interactions with delayed responses so that I can handle delays properly on UI.

6 Replies

Hi @p4j4r5. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave: ---------------------- To add a delay to all responses in a Wasp application, there isn't a built-in feature specifically for this purpose. However, you can achieve this effect by using Wasp's job functionality. Here's how you can approach this: 1. Create a job that wraps your response logic and adds a delay:

import { myResponseJob } from 'wasp/server/jobs'

// In your action or query handler
const delayedResponse = await myResponseJob
  .delay(5) // Delay for 5 seconds
  .submit({ /* your response data */ })

import { myResponseJob } from 'wasp/server/jobs'

// In your action or query handler
const delayedResponse = await myResponseJob
  .delay(5) // Delay for 5 seconds
  .submit({ /* your response data */ })

This approach uses Wasp's job system to add a delay before executing your response logic. You can adjust the delay time as needed for your testing purposes. Jobs Documentation (https://wasp-lang.dev/docs/advanced/jobs) provides more details on how to set up and use jobs in Wasp. Keep in mind that this method will actually delay your server responses, which might not be ideal for production use. For testing UI interactions with delayed responses, you might also consider implementing the delay on the client side or using a mocking library that can simulate delayed responses. If you're specifically looking to test and handle UI interactions during delays, you might want to explore implementing optimistic UI updates. This technique can help improve the perceived performance of your app even when there are server delays. There's an open GitHub issue discussing this for the Waspello example app: Optimistic UI Updates Issue (https://github.com/wasp-lang/wasp/issues/339). Remember, while testing with artificial delays can be useful for development, it's important to optimize for real-world performance in your production environment. ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ---------------------- Sorry @p4j4r5, I seem to be having a bit of trouble. Don't worry though, I've pinged my support and they will try to fix me up! :technologist: Perhaps try again in 15mins?

p4j4r5OP•2w ago

@kapa.ai I tried adding below code and the server doesn't delay the responses . Any idea why?

//File @src/serverSetup.ts
import { config, ServerSetupFn, type MiddlewareConfigFn } from 'wasp/server'
import delay from 'express-delay'
export const slowDownResponses: ServerSetupFn = async ({ app }) => {
    console.log('Setting up slow down responses middleware')
    app.use(delay(2000));
}

//File @src/serverSetup.ts
import { config, ServerSetupFn, type MiddlewareConfigFn } from 'wasp/server'
import delay from 'express-delay'
export const slowDownResponses: ServerSetupFn = async ({ app }) => {
    console.log('Setting up slow down responses middleware')
    app.use(delay(2000));
}

// Main.wasp

  wasp: {
    version: "^0.14.0"
  },
  server: {
    setupFn: import { slowDownResponses } from "@src/serverSetup",
  },

// Main.wasp

  wasp: {
    version: "^0.14.0"
  },
  server: {
    setupFn: import { slowDownResponses } from "@src/serverSetup",
  },

kapa.ai•2w ago

Let me check the knowledge base for you again. One moment! :books:

MEE6•2w ago

Wohooo @p4j4r5, you just became a Waspeteer level 4!

kapa.ai•2w ago

---------------------- Based on the code you've provided, it seems you're trying to use the express-delay middleware to add a delay to all server responses. However, there are a couple of reasons why this might not be working as expected: 1. The setupFn in Wasp is used for initial server setup, but it doesn't directly modify the middleware stack. Instead, Wasp provides a specific function for configuring middleware called middlewareConfigFn. 2. The way you're trying to add the middleware using app.use() is not the recommended approach in Wasp for adding global middleware. To correctly add a delay to all responses in Wasp, you should use the middlewareConfigFn instead. Here's how you can modify your code to achieve this: 1. First, update your main.wasp file:

app MyApp {
  // ... other configurations ...
  server: {
    middlewareConfigFn: import { serverMiddlewareFn } from "@src/serverSetup"
  },
}

app MyApp {
  // ... other configurations ...
  server: {
    middlewareConfigFn: import { serverMiddlewareFn } from "@src/serverSetup"
  },
}

2. Then, modify your @src/serverSetup.ts file:

import { type MiddlewareConfigFn } from 'wasp/server'
import delay from 'express-delay'

export const serverMiddlewareFn: MiddlewareConfigFn = (middlewareConfig) => {
  console.log('Setting up slow down responses middleware')
  middlewareConfig.set('delay', delay(2000))
  return middlewareConfig
}

import { type MiddlewareConfigFn } from 'wasp/server'
import delay from 'express-delay'

export const serverMiddlewareFn: MiddlewareConfigFn = (middlewareConfig) => {
  console.log('Setting up slow down responses middleware')
  middlewareConfig.set('delay', delay(2000))
  return middlewareConfig
}

This approach uses Wasp's middlewareConfigFn to add the express-delay middleware to the global middleware stack. The middlewareConfig.set() method is used to add or override middleware in Wasp. By using this method, the delay middleware should be applied to all routes, causing a 2-second delay for all responses. If you're still experiencing issues after making these changes, make sure that: 1. You've installed the express-delay package in your project. 2. Your Wasp version is compatible with this approach (you're using ^0.14.0, which should support this). 3. You've restarted your Wasp server after making these changes. For more information on configuring middleware in Wasp, you can refer to the Configuring Middleware documentation (https://wasp-lang.dev/docs/advanced/middleware-config#1-customize-global-middleware). ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ---------------------- Sorry @p4j4r5, I seem to be having a bit of trouble. Don't worry though, I've pinged my support and they will try to fix me up! :technologist: Perhaps try again in 15mins?

p4j4r5OP•2w ago

Nice.. that works.

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How to add delay to all responses