<==Back

Name 3 real world use cases where you’d want to change the request with custom middleware

• to alter data before it gets to the route
• edit requests
• logging
• validating
• order array

https://expressjs.com/en/guide/writing-middleware.html

True or false: The route handler is middleware?

• it can be consifered a middleware function and a handler function if it has the req, res, next. they are not opposite of eachother

https://stackoverflow.com/questions/58925276/what-is-the-difference-between-a-route-handler-and-middleware-function-in-expres#:~:text=They%20are%20not%20middleware%20functions,the%20only%20one%20callback%20function.

In what ways can a middleware function end the process and send data to the browser?

• put a string in the next(‘string here’) which trips the error source -myself

At what point in the request lifecycle can you “inject” middleware?

• i think in the middle between the http method and the route its headed

What can cause express to error with “Request headers sent twice, cannot start a second response”

• another function already sent or was used twice

Middleware

• software that acts as a bridge between an operating system or database and applications, esp on a network

Request Object -https://book.cakephp.org/3/en/controllers/request-response.html

Response Object -https://book.cakephp.org/3/en/controllers/request-response.html

Application Middleware

• bound to an instance?
• app.use()

Routing Middleware

• express.Router()

Test Driven Development

• software process relying on software requirements being converted to test cases before the software is fully dev’d

Behavioral Testing ?