Additional tests for TradeAPI utils and public method comments

Author: cgewecke

src/api/TradeAPI.ts

@@ -135,6 +135,25 @@ export default class TradeAPI {
     );
   }
 
+  /**
+   * Call 0x API to generate a trade quote for two SetToken components.
+   *
+   * @param  fromToken            Address of token being sold
+   * @param  toToken              Address of token being bought
+   * @param  fromTokenDecimals    Token decimals of token being sold (ex: 18)
+   * @param  toTokenDecimals      Token decimals of token being bought (ex: 18)
+   * @param  rawAmount            String quantity of token to sell (ex: "0.5")
+   * @param  fromAddress          SetToken address which holds the buy / sell components
+   * @param  setToken             SetTokenAPI instance
+   * @param  gasPrice             (Optional) gasPrice to calculate gas costs with (Default: fetched from GasNow)
+   * @param  slippagePercentage   (Optional) maximum slippage, determines min receive quantity. (Default: 2%)
+   * @param  isFirmQuote          (Optional) Whether quote request is indicative or firm
+   * @param  feePercentage        (Optional) Default: 0
+   * @param  feeRecipient         (Optional) Default: 0xD3D555Bb655AcBA9452bfC6D7cEa8cC7b3628C55
+   * @param  excludedSources      (Optional) Exchanges to exclude (Default: ['Kyber', 'Eth2Dai', 'Uniswap', 'Mesh'])
+   *
+   * @return {Promise<TradeQuote>}
+   */
   public async fetchTradeQuoteAsync(
     fromToken: Address,
     toToken: Address,
@@ -159,7 +178,6 @@ export default class TradeAPI {
 
     const chainId = (await this.provider.getNetwork()).chainId;
 
-    // @ts-ignore
     return this.tradeQuoter.generate({
       fromToken,
       toToken,
@@ -180,30 +198,61 @@ export default class TradeAPI {
     });
   }
 
-  public async fetchTokenList(): Promise<CoinGeckoTokenData[]> {
+  /**
+   * Fetches a list of tokens and their metadata from CoinGecko. Each entry includes
+   * the token's address, proper name, decimals, exchange symbol and a logo URI if available.
+   * For Ethereum, this is a list of tokens tradeable on Uniswap, for Polygon it's a list of
+   * tokens tradeable on Sushiswap's Polygon exchange. Method is useful for acquiring token decimals
+   * necessary to generate a trade quote and images for representing available tokens in a UI.
+   *
+   * @return List of tradeable tokens for chain platform
+   */
+  public async fetchTokenListAsync(): Promise<CoinGeckoTokenData[]> {
     await this.initializeForChain();
     return this.coinGecko.fetchTokenList();
   }
 
-  public async fetchTokenMap(): Promise<CoinGeckoTokenMap> {
+  /**
+   * Fetches the same info as `fetchTokenList` in the form of a map indexed by address. Method is
+   * useful if you're cacheing the token list and want quick lookups for a variety of trades.
+   *
+   * @return Map of token addresses to token metadata
+   */
+  public async fetchTokenMapAsync(): Promise<CoinGeckoTokenMap> {
     await this.initializeForChain();
     return this.coinGecko.fetchTokenMap();
   }
 
-  public async fetchCoinPrices(
+  /**
+   * Fetches a list of prices vs currencies for the specified inputs from CoinGecko
+   *
+   * @param  contractAddresses         String array of contract addresses
+   * @param  vsCurrencies              String array of currency codes (see CoinGecko api for a complete list)
+   *
+   * @return                           List of prices vs currencies
+   */
+  public async fetchCoinPricesAsync(
     contractAddresses: string[],
     vsCurrencies: string[]
   ): Promise<CoinGeckoCoinPrices> {
     await this.initializeForChain();
     return this.coinGecko.fetchCoinPrices({contractAddresses, vsCurrencies});
   }
 
-  public async fetchGasPrice(speed: GasOracleSpeed): Promise<number> {
+  /**
+   * Fetches the recommended gas price for a specified execution speed.
+   *
+   * @param  speed                   (Optional) string value: "average" | "fast" | "fastest" (Default: fast)
+   *
+   * @return                         Number: gas price
+   */
+  public async fetchGasPriceAsync(speed?: GasOracleSpeed): Promise<number> {
     await this.initializeForChain();
     const oracle = new GasOracleService(this.chainId);
     return oracle.fetchGasPrice(speed);
   }
 
+
   private async initializeForChain() {
     if (this.coinGecko === undefined) {
       const network = await this.provider.getNetwork();

src/api/utils/coingecko.ts

@@ -122,6 +122,24 @@ export class CoinGeckoDataService {
     return this.tokenMap;
   }
 
+  public convertTokenListToAddressMap(list: CoinGeckoTokenData[] = []): CoinGeckoTokenMap {
+    const tokenMap: CoinGeckoTokenMap = {};
+
+    for (const entry of list) {
+      tokenMap[entry.address] = Object.assign({}, entry);
+    }
+
+    return tokenMap;
+  }
+
+  private getPlatform(): string {
+    switch (this.chainId) {
+      case 1: return 'ethereum';
+      case 137: return 'polygon-pos';
+      default: return '';
+    }
+  }
+
   private async fetchEthereumTokenList(): Promise<CoinGeckoTokenData[]> {
     const url = 'https://tokens.coingecko.com/uniswap/all.json';
     const response = await axios.get(url);
@@ -226,22 +244,4 @@ export class CoinGeckoDataService {
     const data = (await axios.get(url)).data;
     return data;
   }
-
-  private convertTokenListToAddressMap(list: CoinGeckoTokenData[] = []): CoinGeckoTokenMap {
-    const tokenMap: CoinGeckoTokenMap = {};
-
-    for (const entry of list) {
-      tokenMap[entry.address] = Object.assign({}, entry);
-    }
-
-    return tokenMap;
-  }
-
-  private getPlatform(): string {
-    switch (this.chainId) {
-      case 1: return 'ethereum';
-      case 137: return 'polygon-pos';
-      default: return '';
-    }
-  }
 }

src/api/utils/gasOracle.ts

@@ -67,7 +67,6 @@ export class GasOracleService {
     const url = 'https://www.gasnow.org/api/v3/gas/price';
     const data: GasNowData = (await axios.get(url)).data.data;
 
-    // EthGasStation returns gas price in x10 Gwei (divite by 10 to convert it to gwei)
     switch (speed) {
       case GasOracleService.AVERAGE: return data.standard / 1e9;
       case GasOracleService.FAST:    return data.fast / 1e9;

src/api/utils/tradeQuoter.ts

@@ -235,7 +235,7 @@ export class TradeQuoter {
 
     const fromTokenAmount = quote.sellAmount;
 
-    // Convert to BigDecimal to get cieling in fromUnits calculation
+    // Convert to BigDecimal to get ceiling in fromUnits calculation
     // This is necessary to derive the trade amount ZeroEx expects when scaling is
     // done in the TradeModule contract. (ethers.FixedNumber does not work for this case)
     const fromTokenAmountBD = new BigDecimal(fromTokenAmount.toString());
@@ -422,8 +422,7 @@ export class TradeQuoter {
       const gasCostBuffer = (100 + this.tradeQuoteGasBuffer) / 100;
       return Math.floor(gas.toNumber() * gasCostBuffer);
     } catch (error) {
-      console.log('error --> ' + error);
-      throw new Error('Unable to fetch gas cost estimate for trade');
+      throw new Error('Unable to fetch gas cost estimate for trade' + error);
     }
   }
 

src/assertions/CommonAssertions.ts

@@ -120,7 +120,7 @@ export class CommonAssertions {
     const validChainIds = [1, 137];
 
     if ( !validChainIds.includes(chainId)) {
-      throw new Error('Unsupported chainId: ${chainId}. Must be one of ${validChainIds}');
+      throw new Error(`Unsupported chainId: ${chainId}. Must be one of ${validChainIds}`);
     }
   }
 }