由于 json 的循环结构，我不断获得状态 500

Question

I'm creating a microservice by calling another API inside this API. The other API returns the data but I keep getting this error

This is payment Response { success: true, json: 1 } (node:31709) UnhandledPromiseRejectionWarning: TypeError: Converting circular structure to JSON at JSON.stringify () at stringify (/Users/greatness/microservice/order/node_modules/express/lib/response.js:1119:12) at ServerResponse.json (/Users/alpha/setel/order/node_modules/express/lib/response.js:260:14) at router.post (/Users/alpha/setel/order/src/routes/order.js:59:21) at at process._tickCallback (internal/process/next_tick.js:189:7) (node:31709) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 2)

router.post("/order", async (req, res) => {

    let paymentResponse;

    // Im using Mongoose
    const order = new Order()

   try {
        // Call the payment API
        paymentResponse = await axios.post('http://localhost:3002/api/v1/payment', {
            order
        })

    } catch (err) {

        res.status(500).json({
            success: false,
            message: err.message
        })
    }

    console.log("This is payment Response", paymentResponse.data)

    // Success change the order status to confirmed
    if (paymentResponse.data.json === 0) {
        order.status = "confirmed"
    } else {
        order.status = "declined"
    }

    order.save()
    res.status(200).json({
        success: true,
        paymentResponse,
        order
    })
})

The other just returning normal json

router.post("/v1/payment", async (req, res) => {

    try {


        // If 0 confirmed if 1 declined
        const randomResponse = Math.round(Math.random())
        res.status(200).json({
            success: true,
            json: randomResponse
        })

    } catch (err) {
        res.status(500).json({
            success: false,
            message: err.message
        })
    }
})

What can I do? I keep getting status 500.

Regards.

Answer 1

You're calling json with like this:

res.status(200).json({
    success: true,
    paymentResponse, <---
    order
})

The paymentResponse is a response object from axios, this is NOT a simple json, rather a complex JS objects with methods, properties and circular references. What you want to do, is to send only the raw data like this:

res.status(200).json({
    success: true,
    paymentResponse: paymentResponse.data, <--- Make sure the response from payment is valid json!
    order
})