MyCrypto/common/libs/nodes/etherscan/client.ts

import RPCClient from '../rpc/client';
import { JsonRpcResponse } from '../rpc/types';
import { EtherscanRequest } from './types';

export default class EtherscanClient extends RPCClient {
  public encodeRequest(request: EtherscanRequest): string {
    const encoded = new URLSearchParams();
    Object.keys(request).forEach(key => {
      if (request[key]) {
        encoded.set(key, request[key]);
      }
    });
    return encoded.toString();
  }

  public call = (request: EtherscanRequest): Promise<JsonRpcResponse> =>
    fetch(this.endpoint, {
      method: 'POST',
      headers: new Headers({
        'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'
      }),
      body: this.encodeRequest(request)
    }).then(r => r.json());

  public batch = (requests: EtherscanRequest[]): Promise<JsonRpcResponse[]> => {
    const promises = requests.map(req => this.call(req));
    return Promise.all(promises);
  };
}