Tolerate invalid control chars in RPC JSON

apps/indexer/src/rpc.ts

@@ -8,6 +8,60 @@ type JsonRpcEnvelope<T> = {
   };
 };
 
+function escapeControlCharactersInStrings(payload: string): string {
+  let result = "";
+  let inString = false;
+  let escaping = false;
+
+  for (let index = 0; index < payload.length; index += 1) {
+    const char = payload[index];
+
+    if (!inString) {
+      if (char === "\"") {
+        inString = true;
+      }
+      result += char;
+      continue;
+    }
+
+    if (escaping) {
+      result += char;
+      escaping = false;
+      continue;
+    }
+
+    if (char === "\\") {
+      result += char;
+      escaping = true;
+      continue;
+    }
+
+    if (char === "\"") {
+      result += char;
+      inString = false;
+      continue;
+    }
+
+    const code = char.charCodeAt(0);
+    if (code <= 0x1f) {
+      result += `\\u${code.toString(16).padStart(4, "0")}`;
+      continue;
+    }
+
+    result += char;
+  }
+
+  return result;
+}
+
+function parseRpcPayload<T>(payload: string): T {
+  try {
+    return JSON.parse(payload) as T;
+  } catch {
+    return JSON.parse(escapeControlCharactersInStrings(payload)) as T;
+  }
+}
+
 export type RpcBlockHeader = {
   hash: string;
   height: number;
@@ -94,7 +148,7 @@ export class PeyaRpcClient {
       throw new Error(`RPC ${method} failed with HTTP ${response.status}`);
     }
 
-    const payload = (await response.json()) as JsonRpcEnvelope<T>;
+    const payload = parseRpcPayload<JsonRpcEnvelope<T>>(await response.text());
     if (payload.error) {
       throw new Error(`RPC ${method} failed: ${payload.error.code} ${payload.error.message}`);
     }
@@ -109,7 +163,7 @@ export class PeyaRpcClient {
     if (!response.ok) {
       throw new Error(`GET /getheight failed with HTTP ${response.status}`);
     }
-    return (await response.json()) as RpcGetHeightResult;
+    return parseRpcPayload<RpcGetHeightResult>(await response.text());
   }
 
   async getBlock(height: number): Promise<RpcGetBlockResult> {
@@ -135,7 +189,7 @@ export class PeyaRpcClient {
     if (!response.ok) {
       throw new Error(`POST /gettransactions failed with HTTP ${response.status}`);
     }
-    return (await response.json()) as RpcGetTransactionsResult;
+    return parseRpcPayload<RpcGetTransactionsResult>(await response.text());
   }
 
   async getYieldInfo(fromHeight: number, toHeight: number): Promise<RpcYieldInfoResult> {