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javascriptjsonnode.jsnode-fetch

Node-fetch returns Promise { <pending> } instead of desired data

I am currently trying to fetch JSON from a website using the node-fetch module, and have made the following function:

var fetch = require("node-fetch");

function getJSON(URL) {
  return fetch(URL)
    .then(function(res) {
      return res.json();
    }).then(function(json) {
      //console.log(json) logs desired data
      return json;
  });
}

console.log(getJson("http://api.somewebsite/some/destination")) //logs Promise { <pending> }

When this is printed to the console, I simply receive Promise { <pending> } However, if I print the variable json to the command line from the last .then function, I get the desired JSON data. Is there any way to return that same data?

(I apologize in advance if this is just a misunderstanding issue on my part, as I am rather new to Javascript)

Solution

  • A JavaScript Promise is asynchronous. Your function is not.

    When you print the return value of the function it will immediately return the Promise (which is still pending).

    Example:

    var fetch = require("node-fetch");

// Demonstational purpose, the function here is redundant
function getJSON(URL) {
  return fetch(URL);
}

getJson("http://api.somewebsite/some/destination")
.then(function(res) {
  return res.json();
}).then(function(json) {
  console.log('Success: ', json);
})
.catch(function(error) {
  console.log('Error: ', error);
});