Why is react not posting res.json() to console? - node.js

Question

I have tried so many thing but my react app is not recieving jsonData variable or res as a return from the node app. The app is working and printing to console on the node side but I can't get it to print onto the react side.
const submitForm = async (event) => {
event.preventDefault(); // Prevent default submission
const data2 = document.getElementById("miles").value;
const data =
"passenger_vehicle-vehicle_type_" +
carType +
"-fuel_source_" +
vehicleType +
"-engine_size_na-vehicle_age_na-vehicle_weight_na";
axios
.post(`http://localhost:8000/api/vehicle/`, { data, data2 })
.then((res) => {
const returnText = res.json();
console.log(returnText);
return res.json();
})
.then((jsonData) => {
console.log(jsonData);
return;
})
.catch((error) => {
console.log("got errr while posting data", error);
});
};
I edited out the api and api key.
var fetch = require('node-fetch');
exports.vehicle = (req, res) =>{
let status;
const { data, data2 } = res.body;
const values = {
"emission_factor": data,
"parameters": {
"distance": parseInt(data2),
"distance_unit": "mi",
},
};
fetch('https://AAAAAAAAAAAAAAAA', {
method: 'POST',
headers: {
'Authorization': 'Bearer MYAPIKEY',
'Content-Type': 'application/json'
},
body: JSON.stringify(values)
})
.then((res) => {
status = res.status;
return res.json()
})
.then((jsonData) => {
console.log(jsonData);
console.log(status);
return jsonData
})
.catch((err) => {
// handle error
console.error(err);
});
res.send(req.body);
}
Working code thanks for the help:
const submitForm = async (event) => {
event.preventDefault(); // Prevent default submission
const data2 = document.getElementById("miles").value;
const data =
"passenger_vehicle-vehicle_type_" +
carType +
"-fuel_source_" +
vehicleType +
"-engine_size_na-vehicle_age_na-vehicle_weight_na";
axios
.post(`http://localhost:8000/api/vehicle/`, { data, data2 })
.then((res) => {
console.log(res.data);
return;
})
.catch((error) => {
console.log("got err while posting data", error);
});
};
Node solution in comments.

Answer 1

The functions inside your then() statements need to return data e.g. then((res) => {return res.json()})

Answer 2

You have two problems here...
Client-side, you seem to be mixing up an Axios response with a fetch() Response. You want res.data, not res.json(). Since you've tagged this with reactjs, here is where you would set the data to a state value, eg
axios.post(...).then(res => {
setSomeState(res.data)
})
Server-side, you aren't waiting for your fetch request to complete. I'd recommend using an async function
exports.vehicle = async (req, res) => {
try {
const { data, data2 } = req.body
const values = {
"emission_factor": data,
"parameters": {
"distance": parseInt(data2),
"distance_unit": "mi",
},
}
// don't mix up the Express "res" with the fetch "response"
const response = await fetch('https://AAAAAAAAAAAAAAAA', {
method: 'POST',
headers: {
'Authorization': 'Bearer MYAPIKEY',
'Content-Type': 'application/json'
},
body: JSON.stringify(values)
})
if (!response.ok) {
throw new Error(`${response.status}: ${await response.text()}`)
}
res.json(await response.json()) // respond with the data
} catch (err) {
console.error(err)
res.status(500).send(err)
}
}