@metamask/ethjs-query/lib/index.js

A simple query layer for the Ethereum RPC.

"use strict";

var format = require('@metamask/ethjs-format');
var EthRPC = require('@metamask/ethjs-rpc');
var promiseToCallback = require('promise-to-callback');
module.exports = Eth;
function Eth(provider, options) {
  var self = this;
  var optionsObject = options || {};
  if (!(this instanceof Eth)) {
    throw new Error('[ethjs-query] the Eth object requires the "new" flag in order to function normally (i.e. `const eth = new Eth(provider);`).');
  }
  if (typeof provider !== 'object') {
    throw new Error("[ethjs-query] the Eth object requires that the first input 'provider' must be an object, got '" + typeof provider + "' (i.e. 'const eth = new Eth(provider);')");
  }
  self.options = Object.assign({
    debug: optionsObject.debug || false,
    logger: optionsObject.logger || console,
    jsonSpace: optionsObject.jsonSpace || 0
  });
  self.rpc = new EthRPC(provider);
  self.setProvider = self.rpc.setProvider;
}
Eth.prototype.log = function log(message) {
  var self = this;
  if (self.options.debug) self.options.logger.log("[ethjs-query log] " + message);
};
Object.keys(format.schema.methods).forEach(function (rpcMethodName) {
  Object.defineProperty(Eth.prototype, rpcMethodName.replace('eth_', ''), {
    enumerable: true,
    value: generateFnFor(rpcMethodName, format.schema.methods[rpcMethodName])
  });
});
function generateFnFor(rpcMethodName, methodObject) {
  return function outputMethod() {
    var callback = null; // eslint-disable-line
    var inputs = null; // eslint-disable-line
    var inputError = null; // eslint-disable-line
    var self = this;
    var args = [].slice.call(arguments); // eslint-disable-line
    var protoMethodName = rpcMethodName.replace('eth_', ''); // eslint-disable-line

    if (args.length > 0 && typeof args[args.length - 1] === 'function') {
      callback = args.pop();
    }
    var promise = performCall.call(this);

    // if callback provided, convert promise to callback
    if (callback) {
      return promiseToCallback(promise)(callback);
    }

    // only return promise if no callback provided
    return promise;
    function performCall() {
      var _this = this;
      return new Promise(function (resolve, reject) {
        // validate arg length
        if (args.length < methodObject[2]) {
          reject(new Error("[ethjs-query] method '" + protoMethodName + "' requires at least " + methodObject[2] + " input (format type " + methodObject[0][0] + "), " + args.length + " provided. For more information visit: https://github.com/ethereum/wiki/wiki/JSON-RPC#" + rpcMethodName.toLowerCase()));
          return;
        }
        if (args.length > methodObject[0].length) {
          reject(new Error("[ethjs-query] method '" + protoMethodName + "' requires at most " + methodObject[0].length + " params, " + args.length + " provided '" + JSON.stringify(args, null, self.options.jsonSpace) + "'. For more information visit: https://github.com/ethereum/wiki/wiki/JSON-RPC#" + rpcMethodName.toLowerCase()));
          return;
        }

        // set default block
        if (methodObject[3] && args.length < methodObject[3]) {
          args.push('latest');
        }

        // format inputs
        _this.log("attempting method formatting for '" + protoMethodName + "' with inputs " + JSON.stringify(args, null, _this.options.jsonSpace));
        try {
          inputs = format.formatInputs(rpcMethodName, args);
          _this.log("method formatting success for '" + protoMethodName + "' with formatted result: " + JSON.stringify(inputs, null, _this.options.jsonSpace));
        } catch (formattingError) {
          reject(new Error("[ethjs-query] while formatting inputs '" + JSON.stringify(args, null, _this.options.jsonSpace) + "' for method '" + protoMethodName + "' error: " + formattingError));
          return;
        }

        // perform rpc call
        _this.rpc.sendAsync({
          method: rpcMethodName,
          params: inputs
        }).then(function (result) {
          // format result
          _this.log("attempting method formatting for '" + protoMethodName + "' with raw outputs: " + JSON.stringify(result, null, _this.options.jsonSpace));
          var methodOutputs = format.formatOutputs(rpcMethodName, result);
          _this.log("method formatting success for '" + protoMethodName + "' formatted result: " + JSON.stringify(methodOutputs, null, _this.options.jsonSpace));
          resolve(methodOutputs);
        })["catch"](function (error) {
          reject(error);
        });
      });
    }
  };
}