add retries for commitment in case of connection errors

src/helpers/common.ts

@@ -1,7 +1,8 @@
+import { JRPCResponse } from "@toruslabs/constants";
 import { Ecies } from "@toruslabs/eccrypto";
 import JsonStringify from "json-stable-stringify";
 
-import { EciesHex, VerifierLookupResponse } from "../interfaces";
+import { CommitmentRequestResult, EciesHex, VerifierLookupResponse } from "../interfaces";
 
 // this function normalizes the result from nodes before passing the result to threshold check function
 // For ex: some fields returns by nodes might be different from each other
@@ -104,3 +105,60 @@ export function calculateMedian(arr: number[]): number {
   const mid2 = sortedArr[arrSize / 2];
   return (mid1 + mid2) / 2;
 }
+
+export function waitFor(milliseconds: number) {
+  return new Promise((resolve, reject) => {
+    // hack to bypass eslint warning.
+    if (milliseconds > 0) {
+      setTimeout(resolve, milliseconds);
+    } else {
+      reject(new Error("value of milliseconds must be greater than 0"));
+    }
+  });
+}
+
+export function retryCommitment(executionPromise: () => Promise<JRPCResponse<CommitmentRequestResult>>, maxRetries: number) {
+  // Notice that we declare an inner function here
+  // so we can encapsulate the retries and don't expose
+  // it to the caller. This is also a recursive function
+  async function retryWithBackoff(retries: number) {
+    try {
+      // we don't wait on the first attempt
+      if (retries > 0) {
+        // on every retry, we exponentially increase the time to wait.
+        // Here is how it looks for a `maxRetries` = 4
+        // (2 ** 1) * 100 = 200 ms
+        // (2 ** 2) * 100 = 400 ms
+        // (2 ** 3) * 100 = 800 ms
+        const timeToWait = 2 ** retries * 100;
+        await waitFor(timeToWait);
+      }
+      const a = await executionPromise();
+      return a;
+    } catch (e: unknown) {
+      const errorMsg = (e as Error).message;
+      const acceptedErrorMsgs = [
+        // Slow node
+        "Timed out",
+        "Failed to fetch",
+        "fetch failed",
+        "Load failed",
+        "cancelled",
+        "NetworkError when attempting to fetch resource.",
+        // Happens when the node is not reachable (dns issue etc)
+        "TypeError: Failed to fetch", // All except iOS and Firefox
+        "TypeError: cancelled", // iOS
+        "TypeError: NetworkError when attempting to fetch resource.", // Firefox
+      ];
+
+      if (retries < maxRetries && (acceptedErrorMsgs.includes(errorMsg) || (errorMsg && errorMsg.includes("reason: getaddrinfo EAI_AGAIN")))) {
+        // only retry if we didn't reach the limit
+        // otherwise, let the caller handle the error
+        return retryWithBackoff(retries + 1);
+      }
+      throw e;
+    }
+  }
+
+  return retryWithBackoff(0);
+}

src/helpers/nodeUtils.ts

@@ -23,7 +23,7 @@ import {
 } from "../interfaces";
 import log from "../loglevel";
 import { Some } from "../some";
-import { calculateMedian, kCombinations, normalizeKeysResult, thresholdSame } from "./common";
+import { calculateMedian, kCombinations, normalizeKeysResult, retryCommitment, thresholdSame } from "./common";
 import { generateAddressFromPrivKey, generateAddressFromPubKey, keccak256 } from "./keyUtils";
 import { lagrangeInterpolation } from "./langrangeInterpolatePoly";
 import { decryptNodeData, getMetadata, getOrSetNonce, getOrSetSapphireMetadataNonce } from "./metadataUtils";
@@ -209,19 +209,21 @@ export async function retrieveOrImportShare(params: {
         VerifierIdentifier string `json:"verifieridentifier"`
       } 
       */
-    const p = post<JRPCResponse<CommitmentRequestResult>>(
-      endpoints[i],
-      generateJsonRPCObject(JRPC_METHODS.COMMITMENT_REQUEST, {
-        messageprefix: "mug00",
-        tokencommitment: tokenCommitment.slice(2),
-        temppubx: pubKeyX,
-        temppuby: pubKeyY,
-        verifieridentifier: verifier,
-      }),
-      null,
-      { logTracingHeader: config.logRequestTracing }
-    );
-    promiseArr.push(p);
+    const p = () =>
+      post<JRPCResponse<CommitmentRequestResult>>(
+        endpoints[i],
+        generateJsonRPCObject(JRPC_METHODS.COMMITMENT_REQUEST, {
+          messageprefix: "mug00",
+          tokencommitment: tokenCommitment.slice(2),
+          temppubx: pubKeyX,
+          temppuby: pubKeyY,
+          verifieridentifier: verifier,
+        }),
+        null,
+        { logTracingHeader: config.logRequestTracing }
+      );
+    const r = retryCommitment(p, 4);
+    promiseArr.push(r);
   }
   // send share request once k + t number of commitment requests have completed
   return Some<void | JRPCResponse<CommitmentRequestResult>, (void | JRPCResponse<CommitmentRequestResult>)[]>(promiseArr, (resultArr) => {