ParaSwap

1import axios, { AxiosError, AxiosRequestConfig } from 'axios';
2import * as qs from 'qs';
3import * as _ from 'lodash';
4import Web3 from 'web3';
5import type { SendOptions } from 'web3-eth-contract';
6​
7import {
8  Adapters,
9  Address,
10  AddressOrSymbol,
11  Allowance,
12  APIError,
13  BuildOptions,
14  NetworkID,
15  PriceString,
16  RateOptions,
17  Transaction,
18  OptimalRatesWithPartnerFees,
19} from './types';
20​
21import ERC20_ABI = require('./abi/erc20.json');
22​
23import AUGUSTUS_ABI = require('./abi/augustus-v4.json');
24​
25import { Token } from './lib/token';
26import { NULL_ADDRESS, TransactionBuilder } from './lib/transaction-builder';
27import {
28  SwapSide,
29  latestAugustusVersion,
30  AdapterAugustusVersionMap,
31} from './constants';
32​
33const API_URL = 'https://apiv4.paraswap.io/v2';
34​
35export class ParaSwap {
36  adapters?: Adapters;
37  tokens: Token[] = [];
38​
39  constructor(
40    private network: NetworkID = 1,
41    private apiURL: string = API_URL,
42    public web3Provider?: any,
43  ) {
44    if (web3Provider && !web3Provider.eth) {
45      this.web3Provider = new Web3(web3Provider);
46    }
47  }
48​
49  setWeb3Provider(web3Provider: any) {
50    if (!web3Provider.eth) {
51      this.web3Provider = new Web3(web3Provider);
52    } else {
53      this.web3Provider = web3Provider;
54    }
55    return this;
56  }
57​
58  private handleAPIError(e: AxiosError): APIError {
59    if (e.response) {
60      const { data, status } = e.response!;
61      return { status, message: data.error, data };
62    }
63    return new Error(e.message);
64  }
65​
66  async getTokens() {
67    try {
68      const tokensURL = `${this.apiURL}/tokens/${this.network}`;
69      const { data } = await axios.get(tokensURL);
70      this.tokens = (data.tokens as Token[]).map(
71        t =>
72          new Token(
73            t.address,
74            t.decimals,
75            t.symbol,
76            t.tokenType,
77            t.mainConnector,
78            t.connectors,
79            t.network,
80            t.img,
81          ),
82      );
83      return this.tokens;
84    } catch (e) {
85      return this.handleAPIError(e);
86    }
87  }
88​
89  async getAdapters() {
90    try {
91      const { data } = await axios.get(
92        `${this.apiURL}/adapters/${this.network}`,
93      );
94​
95      this.adapters = data;
96​
97      return this.adapters;
98    } catch (e) {
99      return this.handleAPIError(e);
100    }
101  }
102​
103  private checkDexList(dexs?: string) {
104    if (dexs) {
105      const targetDEXs = dexs.split(',');
106​
107      if (!targetDEXs.length) {
108        throw new Error('Invalid DEX list');
109      }
110    }
111  }
112​
113  async getRateByRoute(
114    route: AddressOrSymbol[],
115    amount: PriceString,
116    side: SwapSide,
117    options?: RateOptions,
118    srcDecimals?: number,
119    destDecimals?: number,
120  ): Promise<OptimalRatesWithPartnerFees | APIError> {
121    try {
122      const {
123        excludeDEXS,
124        includeDEXS,
125        excludePricingMethods,
126        excludeContractMethods,
127        includeContractMethods,
128        adapterVersion,
129        excludePools,
130        referrer,
131        maxImpact,
132        maxUSDImpact,
133      } = options || {};
134​
135      / TODO: all use typed enum for include/excludeDEXS
136      / TODO: check the semver validity for the adapterVersion
137      this.checkDexList(includeDEXS);
138      this.checkDexList(excludeDEXS);
139​
140      const _excludePricingMethods = excludePricingMethods
141        ? excludePricingMethods.join(',')
142        : '';
143      const _excludeContractMethods = excludeContractMethods
144        ? excludeContractMethods.join(',')
145        : '';
146      const _includeContractMethods = includeContractMethods
147        ? includeContractMethods.join(',')
148        : '';
149​
150      if (route.length < 2) {
151        return { message: 'Invalid Route' };
152      }
153​
154      const query = qs.stringify({
155        excludeDEXS,
156        includeDEXS,
157        excludePools,
158        version: adapterVersion,
159        excludePricingMethods: _excludePricingMethods,
160        excludeContractMethods: _excludeContractMethods,
161        includeContractMethods: _includeContractMethods,
162        fromDecimals: srcDecimals,
163        toDecimals: destDecimals,
164        maxImpact,
165        maxUSDImpact,
166      });

Solidity Contracts

JavaScript Tests