How to get the "end" event from http with fetch API

Question

I want to use the API fetch instead of the http(Node) module. However, I’m not getting the end of the request.

var req = http.request(options, res => {
    res.setEncoding("utf8");
    res.on('data', () => {
      //como entro nesse trecho com o fetch ???
    });
    res.on("end", () => {
      //como entro nesse trecho com o fetch ???
    });
  });

I want to catch these "events" with the fetch ???

fetch(_end, options)
                .then(res => {
                    res.on('data', () => { 
                      //Não exite esse res.on utilizando o fetch
                    });
                    res.on("end", () => {
                        //Não exite esse res.on utilizando o fetch.
                    });
                })
                .catch(err => {
                    ...
                });

Can anyone give me any hint on how to do this using the fetch API.

Answer 1

The fetch and the request has different Apis. fetch returns a file and state control is done by API of the Promise with the .then, .catch and .finally; while the request works with events.

So you can choose to run code on:

• then: called when all goes well
• catch: called when something goes wrong (it should always be set to the code not stop if there is an error)
• finally: called whether Promise has been resolved or rejected

Example:

fetch('https://jsonplaceholder.typicode.com/todos/')
  .then(async response => {
    const dados = await response.json();
    console.log('Tudo correu bem!');
    console.log('Qtd de dados:', dados.length);
  })
  .catch(err => console.log('Houve um erro!', err))
  .finally(() => console.log('The end!...'));