feat: Implement waterfall style fallback provider to improve performance

- Replace ethers fallback provider with a simple waterfall-style provider that allows
  redundancy without costing any performance.
- Fix issue with card deeplink race condition (view binding not set before invokeUrlAction
  is invoked).

Author: micwallace

javascript/card-sdk/src/ethereum/WaterfallFallbackProvider.ts

@@ -0,0 +1,30 @@
+import {AbstractProvider, getBigInt, Network, PerformActionRequest} from "ethers";
+
+export class WaterfallFallbackProvider extends AbstractProvider {
+
+	constructor(private providers: Array<AbstractProvider>) {
+		super();
+	}
+
+	async _detectNetwork(): Promise<Network> {
+		return Network.from(getBigInt(await this._perform({ method: "chainId" })));
+	}
+
+	async _perform<T = any>(req: PerformActionRequest): Promise<T> {
+
+		for (const provider of this.providers){
+			try {
+				return provider._perform(req);
+			} catch (e) {
+				console.error("Provider error, falling back to next provider ", e);
+			}
+		}
+	}
+
+	async destroy(): Promise<void> {
+		for (const provider of this.providers) {
+			provider.destroy();
+		}
+		super.destroy();
+	}
+}

javascript/card-sdk/src/index.ts

@@ -13,6 +13,7 @@ import {
 import {IEngineAdapter, RequestFromView} from "./messaging/IEngineAdapter";
 import {PostMessageAdapter} from "./messaging/PostMessageAdapter";
 import {LocalStorageAdapter} from "./storage/localStorageAdapter";
+import {WaterfallFallbackProvider} from "./ethereum/WaterfallFallbackProvider";
 
 export interface IChainConfig {
     rpc: string|string[],
@@ -146,9 +147,7 @@ class TokenScriptSDK  implements ITokenScriptSDK {
                 for (const url of rpcUrls){
                     providers.push(new ethers.JsonRpcProvider(url, chain, { staticNetwork: new Network(chain.toString(), chain) }));
                 }
-                return new ethers.FallbackProvider(providers, chain, {
-                    quorum: 2
-                });
+                return new WaterfallFallbackProvider(providers);
             } else {
                 return new ethers.JsonRpcProvider(rpcUrls[0], chain, { staticNetwork: new Network(chain.toString(), chain) });
             }

javascript/card-sdk/src/messaging/PostMessageAdapter.ts

@@ -40,6 +40,7 @@ export class PostMessageAdapter implements IEngineAdapter {
 		switch (event.data?.method) {
 			case ViewEvent.TOKENS_UPDATED:
 				this.sdk.tokens.dataChanged(params.oldTokens, params.updatedTokens, params.cardId);
+				//this.sdk.emitEvent("DATA_CHANGED", params);
 				break;
 
 			case ViewEvent.ON_CONFIRM:

javascript/card-sdk/src/types/index.ts

@@ -45,7 +45,7 @@ export interface ITokenScriptSDK {
 		showLoader: () => void,
 		hideLoader: () => void,
 		setActionButton: (options: { show?: boolean, disable?: boolean, text?: string }) => void,
-		executeTransaction: (txName?: string|TXOptions, listener?: ITransactionListener) => Promise<any|false>,
+		executeTransaction: (optionsOrTxName?: string|TXOptions, listener?: ITransactionListener) => Promise<ITransactionStatus|false>,
 		showTransactionToast: (status: "submitted"|"confirmed", chain: number, txHash: string) => void,
 		showMessageToast: (type: 'success'|'info'|'warning'|'error', title: string, description: string) => void,
 		closeCard: () => void,

javascript/engine-js/src/view/sdk/v1.txt

@@ -10,6 +10,7 @@ import {
 } from "ethers";
 import {ITransactionListener} from "../TokenScript";
 import {ErrorDecoder, ErrorType} from "ethers-decode-error";
+import {WaterfallFallbackProvider} from "./WaterfallFallbackProvider";
 
 export interface IChainConfig {
 	rpc: string|string[],
@@ -23,7 +24,7 @@ export class EthersAdapter implements IWalletAdapter {
 
 	private ethersProvider: ethers.BrowserProvider;
 
-	private rpcProviders: {[chainId: number]: ethers.JsonRpcProvider|ethers.FallbackProvider} = {};
+	private rpcProviders: {[chainId: number]: ethers.JsonRpcProvider|WaterfallFallbackProvider} = {};
 
 	constructor(
 		public getWalletEthersProvider: () => Promise<ethers.BrowserProvider>,
@@ -330,18 +331,10 @@ export class EthersAdapter implements IWalletAdapter {
 		const rpcUrls = this.getRpcUrls(chain);
 
 		if (rpcUrls.length > 1){
-			this.rpcProviders[chain] = new ethers.FallbackProvider(
-				rpcUrls.map((url, index) => {
-					return {
-						provider: new ethers.JsonRpcProvider(url, chain, { staticNetwork: new Network(chain.toString(), chain) }),
-						stallTimeout: 3000,
-						priority: index + 1,
-					}
-				}),
-				chain,
-				{
-					quorum: 1
-				}
+			this.rpcProviders[chain] = new WaterfallFallbackProvider(
+				rpcUrls.map((url) => {
+					return new ethers.JsonRpcProvider(url, chain, { staticNetwork: new Network(chain.toString(), chain) })
+				})
 			);
 		} else {
 			this.rpcProviders[chain] = new ethers.JsonRpcProvider(rpcUrls[0], chain, { staticNetwork: new Network(chain.toString(), chain) });

javascript/engine-js/src/wallet/EthersAdapter.ts

@@ -0,0 +1,30 @@
+import {AbstractProvider, getBigInt, Network, PerformActionRequest} from "ethers";
+
+export class WaterfallFallbackProvider extends AbstractProvider {
+
+	constructor(private providers: Array<AbstractProvider>) {
+		super();
+	}
+
+	async _detectNetwork(): Promise<Network> {
+		return Network.from(getBigInt(await this._perform({ method: "chainId" })));
+	}
+
+	async _perform<T = any>(req: PerformActionRequest): Promise<T> {
+
+		for (const provider of this.providers){
+			try {
+				return provider._perform(req);
+			} catch (e) {
+				console.error("Provider error, falling back to next provider ", e);
+			}
+		}
+	}
+
+	async destroy(): Promise<void> {
+		for (const provider of this.providers) {
+			provider.destroy();
+		}
+		super.destroy();
+	}
+}

javascript/engine-js/src/wallet/WaterfallFallbackProvider.ts

@@ -155,7 +155,7 @@ export class TokensGrid {
 				await cardRes.card.isEnabledOrReason(context) === true
 			) {
 				this.urlActionInvoked = true;
-				this.showCard(cardRes.card, token, cardRes.index);
+				setTimeout(() => this.showCard(cardRes.card, token, cardRes.index), 100);
 				return;
 			}
 		}