parse-ring-json-responses.js

'use strict'

const contentType = require( 'content-type' )
const jsonBigIntParse = require( 'json-bigint' )({ storeAsString: true }).parse

const propagatedError = require( './propagated-error' )

const isJson = headers => {
    try {

        const contentTypeHeader = headers[ 'content-type' ]

        if ( !contentTypeHeader ) {
            return false
        }

        const type = ( contentType.parse( contentTypeHeader )).type

        return ( type === 'application/json' )

    } catch ( e ) {
        throw propagatedError( 'could not tell if response is json', e )
    }
}

module.exports = ( responseBody, headers ) => {

    if ( isJson( headers )) {

        try {
            // Some of the ring endpoints return an empty response (but not a 204 status code)
            // while claiming to be JSON. In this case, trying to parse the empty string as
            // json will fail. To avoid the failure, return an empty object
            if ( !responseBody.length ) {
                return {}
            }

            return jsonBigIntParse( responseBody )
        } catch ( e ) {
            throw propagatedError( `invalid json in response: ${responseBody}`, e )
        }
    } else {
        return responseBody
    }
}