Odd response from Github API (Conditional requests)

Question

So I'm trying to retrieve repo data from the Github API for a React app. Due to the rate-limiting on the API, I'm attempting to use conditional requests to check if the data has been modified since the last request, using the If-Modified-Since header.

Here is my test code so far:

const date = new Date().toUTCString();


fetch('https://api.github.com/users/joshlucpoll/repos', {
  headers: {'If-Modified-Since': date}
  })
  .then((res) => {
    let headers = res.headers;
    console.log(headers)
    if (headers.get('status') === "304 Not Modified") {
      console.log("Not modified")
    }
    else {
      console.log("modified")
    }
  });

Every time I run this code I get a 200 OK status, not a 304 Not Modified as expected. The resource can't have updated in the time it's taken to run the code, however, it always outputs "Not modified"...

I can't understand why this isn't working, help would be appreciated!

Answer 1

The issue here is the way you are handling the status.

Here is a little setup on how it should be implemented : https://codesandbox.io/s/wizardly-banzai-pi8to?file=/src/index.js

const date = new Date().toUTCString();

fetch("https://api.github.com/users/joshlucpoll/repos", {
  headers: { "If-Modified-Since": date }
}).then((res) => {
  console.log(res.status);
});

The status can be retrieved inside the response itself, it's not nested inside the headers.

You will see that the value of res.status is 304, res.headers.get("status") will return null