iconHttpProvider.js

const axios = require("axios")

class HttpProvider {
  constructor(url) {
    this.url = url
    this.id = 0
    this.jsonrpc = '2.0'
  }

  // Call JSON RPC method. Get back { id, result } or { id, error }. 
  async call(method, params) {
    const request = {
      jsonrpc: this.jsonrpc,
      id: ++this.id,
      method,
      params
    }
    const body = this.jsonStringify(request)
    try {
      const response = await axios.post(this.url, body)
      return response.data
    } catch (error) {
      if (this.isAxios(error)) {
        return error.response.data
      }
      throw error
    }
  }

  isAxios(error) {
    const keys = Object.keys(error)
    keys.sort()
    return keys[0] === 'config' && keys[1] === 'request' && keys[2] === 'response'
  }

  jsonStringify(request) {
    return JSON.stringify(request, (key, value) => {
      if (value) {
        return value
      }
      return undefined
    })
  }
}