TypeError: Converting circular structure to JSON --> starting at object with constructor 'ClientRequest'

Question

I am a nest.js beginner and I am trying to implement Axios with my code and this error occurs and I would like to fix it.

    --> starting at object with constructor 'ClientRequest'
    |     property 'socket' -> object with constructor 'Socket'
    --- property '_httpMessage' closes the circle +188941ms
TypeError: Converting circular structure to JSON
    --> starting at object with constructor 'ClientRequest'
    |     property 'socket' -> object with constructor 'Socket'
    --- property '_httpMessage' closes the circle
    at JSON.stringify (<anonymous>)
    at stringify (D:\CUSportcomplex-register\sso-reg\node_modules\express\lib\response.js:1123:12)
    at ServerResponse.json (D:\CUSportcomplex-register\sso-reg\node_modules\express\lib\response.js:260:14)
    at ExpressAdapter.reply (D:\CUSportcomplex-register\sso-reg\node_modules\@nestjs\platform-express\adapters\express-adapter.js:24:57)
    at RouterResponseController.apply (D:\CUSportcomplex-register\sso-reg\node_modules\@nestjs\core\router\router-response-controller.js:13:36)
    at D:\CUSportcomplex-register\sso-reg\node_modules\@nestjs\core\router\router-execution-context.js:173:48
    at processTicksAndRejections (internal/process/task_queues.js:93:5)
    at async D:\CUSportcomplex-register\sso-reg\node_modules\@nestjs\core\router\router-execution-context.js:47:13
    at async D:\CUSportcomplex-register\sso-reg\node_modules\@nestjs\core\router\router-proxy.js:9:17

This is my app.service.ts

async validateSSO(appticket): Promise<SsoContent> {
        let instance = axios.create({
            baseURL: "http://localhost:8080/",
            headers: {
                'DeeAppId': config.DeeAppId,
                'DeeAppSecret': config.DeeAppSecret,
                'DeeTicket': appticket
            }
        });
        instance.get("/serviceValidation")
            .then(response => {
                this.ssoContent = response;
            })
            .catch(error => {
                return (error);
            });

        return this.ssoContent;

    }

and this is my app.controller.ts

    @Get('validation/:appticket')
    async validateSSO(
        @Param('appticket') appticket: string
        //DeeAppTicket is sented via Front-end
    ): Promise<SsoContent> {
        return this.registeringService.validateSSO(appticket);
    }

Thank you for your help :)

Answer 1

First of all nest.js provides you HttpService out of the box that you may inject it through DI: https://docs.nestjs.com/techniques/http-module

Second - you are trying to store whole response object which is complex data structure and contains circular dependencies as it stated in error message (TypeError: Converting circular structure to JSON)

What you should do is either you map the data you need instead of storing whole circular object,

or you should look up to some libs that could parse circular json: https://www.npmjs.com/package/flatted