create NonStandardFallbackClass

src/assets/AssetsContractController.ts

@@ -9,6 +9,7 @@ import { NetworkState } from '../network/NetworkController';
 import { ERC721Standard } from './Standards/CollectibleStandards/ERC721/ERC721Standard';
 import { ERC1155Standard } from './Standards/CollectibleStandards/ERC1155/ERC1155Standard';
 import { ERC20Standard } from './Standards/ERC20Standard';
+import { NonStandardFallback } from './Standards/NonStandardFallBack';
 
 /**
  * Check if token detection is enabled for certain networks
@@ -67,6 +68,8 @@ export class AssetsContractController extends BaseController<
 
   private erc20Standard?: ERC20Standard;
 
+  private nonStandardFallback?: NonStandardFallback;
+
   /**
    * Name of this controller used during composition
    */
@@ -129,6 +132,11 @@ export class AssetsContractController extends BaseController<
     this.erc721Standard = new ERC721Standard(this.web3);
     this.erc1155Standard = new ERC1155Standard(this.web3);
     this.erc20Standard = new ERC20Standard(this.web3);
+
+    this.nonStandardFallback = new NonStandardFallback({
+      erc721Standard: this.erc721Standard,
+      erc20Standard: this.erc20Standard,
+    });
   }
 
   get provider() {
@@ -211,7 +219,8 @@ export class AssetsContractController extends BaseController<
     if (
       this.erc721Standard === undefined ||
       this.erc1155Standard === undefined ||
-      this.erc20Standard === undefined
+      this.erc20Standard === undefined ||
+      this.nonStandardFallback === undefined
     ) {
       throw new Error(MISSING_PROVIDER_ERROR);
     }
@@ -253,7 +262,12 @@ export class AssetsContractController extends BaseController<
       // Ignore
     }
 
-    throw new Error('Unable to determine contract standard');
+    return await this.nonStandardFallback.getDetails(
+      tokenAddress,
+      ipfsGateway,
+      userAddress,
+      tokenId,
+    );
   }
 
   /**

src/assets/Standards/CollectibleStandards/ERC721/ERC721Standard.ts

@@ -202,6 +202,38 @@ export class ERC721Standard {
     });
   };
 
+  getTokenURIAndImage = async (
+    address: string,
+    ipfsGateway: string,
+    tokenId: string,
+  ) => {
+    let tokenURI, image;
+
+    try {
+      tokenURI = await this.getTokenURI(address, tokenId);
+      if (tokenURI.startsWith('ipfs://')) {
+        tokenURI = getFormattedIpfsUrl(ipfsGateway, tokenURI, true);
+      }
+    } catch {
+      // ignore
+    }
+
+    if (tokenURI) {
+      try {
+        const response = await timeoutFetch(tokenURI);
+        const object = await response.json();
+        image = object?.image;
+        if (image?.startsWith('ipfs://')) {
+          image = getFormattedIpfsUrl(ipfsGateway, image, true);
+        }
+      } catch {
+        // ignore
+      }
+    }
+
+    return { tokenURI, image };
+  };
+
   /**
    * Query if a contract implements an interface.
    *
@@ -242,21 +274,11 @@ export class ERC721Standard {
     }
 
     if (tokenId) {
-      try {
-        tokenURI = await this.getTokenURI(address, tokenId);
-        if (tokenURI.startsWith('ipfs://')) {
-          tokenURI = getFormattedIpfsUrl(ipfsGateway, tokenURI, true);
-        }
-
-        const response = await timeoutFetch(tokenURI);
-        const object = await response.json();
-        image = object?.image;
-        if (image?.startsWith('ipfs://')) {
-          image = getFormattedIpfsUrl(ipfsGateway, image, true);
-        }
-      } catch {
-        // ignore
-      }
+      ({ tokenURI, image } = await this.getTokenURIAndImage(
+        address,
+        ipfsGateway,
+        tokenId,
+      ));
     }
 
     return {

src/assets/Standards/NonStandardFallBack.ts

@@ -0,0 +1,91 @@
+import { BN } from 'ethereumjs-util';
+import { UNKNOWN_STANDARD } from '../../constants';
+import { ERC721Standard } from './CollectibleStandards/ERC721/ERC721Standard';
+import { ERC20Standard } from './ERC20Standard';
+
+export class NonStandardFallback {
+  private erc20Standard: ERC20Standard;
+
+  private erc721Standard: ERC721Standard;
+
+  constructor({
+    erc20Standard,
+    erc721Standard,
+  }: {
+    erc20Standard: ERC20Standard;
+    erc721Standard: ERC721Standard;
+  }) {
+    this.erc20Standard = erc20Standard;
+    this.erc721Standard = erc721Standard;
+  }
+
+  /**
+   * Query for useful values if a contract does not fully implement one of the three major token interfaces we support (ERC20, ERC721, ERC1155).
+   *
+   * @param address - Asset contract address.
+   * @param ipfsGateway - The user's preferred IPFS gateway.
+   * @param userAddress - The public address for the currently active user's account.
+   * @param tokenId - tokenId of a given token in the contract.
+   * @returns Promise resolving an object containing the standard, decimals, symbol and balance of the given contract/userAddress pair.
+   */
+  async getDetails(
+    address: string,
+    ipfsGateway: string,
+    userAddress?: string,
+    tokenId?: string,
+  ): Promise<{
+    standard: string;
+    symbol: string | undefined;
+    decimals: string | undefined;
+    balance: BN | undefined;
+    name: string | undefined;
+    tokenURI: string | undefined;
+    image: string | undefined;
+  }> {
+    let decimals, symbol, balance, name, image, tokenURI;
+
+    try {
+      decimals = await this.erc20Standard.getTokenDecimals(address);
+    } catch {
+      // ignore
+    }
+
+    try {
+      decimals = await this.erc20Standard.getTokenSymbol(address);
+    } catch {
+      // ignore
+    }
+
+    if (userAddress) {
+      try {
+        balance = await this.erc20Standard.getBalanceOf(address, userAddress);
+      } catch {
+        // ignore
+      }
+    }
+
+    try {
+      name = await this.erc721Standard.getAssetName(address);
+    } catch {
+      // ignore
+    }
+
+    if (tokenId) {
+      ({ tokenURI, image } = await this.erc721Standard.getTokenURIAndImage(
+        address,
+        ipfsGateway,
+        tokenId,
+      ));
+    }
+
+    return {
+      standard: UNKNOWN_STANDARD,
+      decimals,
+      symbol,
+      balance,
+      name,
+      tokenURI,
+      image,
+    };
+  }
+}

src/constants.ts

@@ -10,6 +10,7 @@ export const RINKEBY_CHAIN_ID = '4';
 export const ERC721 = 'ERC721';
 export const ERC1155 = 'ERC1155';
 export const ERC20 = 'ERC20';
+export const UNKNOWN_STANDARD = 'UNKNOWN_STANDARD';
 
 // TOKEN INTERFACE IDS
 export const ERC721_INTERFACE_ID = '0x80ac58cd';