Sanitize nested block JSON before parsing

apps/indexer/src/normalize.ts

@@ -32,11 +32,77 @@ export type NormalizedOutput = {
   rawTarget: OutputTarget;
 };
 
+function sanitizeJsonString(payload: string): string {
+  let result = "";
+  let inString = false;
+
+  for (let index = 0; index < payload.length; index += 1) {
+    const char = payload[index];
+
+    if (!inString) {
+      if (char === "\"") {
+        inString = true;
+      }
+      result += char;
+      continue;
+    }
+
+    if (char === "\\") {
+      const next = payload[index + 1];
+
+      if (next === undefined) {
+        result += "\\\\";
+        continue;
+      }
+
+      if (next === "\"" || next === "\\" || next === "/" || next === "b" || next === "f" || next === "n" || next === "r" || next === "t") {
+        result += "\\";
+        result += next;
+        index += 1;
+        continue;
+      }
+
+      if (next === "u") {
+        const hex = payload.slice(index + 2, index + 6);
+        if (/^[0-9a-fA-F]{4}$/.test(hex)) {
+          result += "\\u";
+          result += hex;
+          index += 5;
+          continue;
+        }
+      }
+
+      result += "\\\\";
+      continue;
+    }
+
+    if (char === "\"") {
+      result += char;
+      inString = false;
+      continue;
+    }
+
+    const code = char.charCodeAt(0);
+    if (code <= 0x1f) {
+      result += `\\u${code.toString(16).padStart(4, "0")}`;
+      continue;
+    }
+
+    result += char;
+  }
+
+  return result;
+}
+
 export function parseRpcJson<T>(value: string | undefined): T | null {
   if (!value) {
     return null;
   }
-  return JSON.parse(value) as T;
+  try {
+    return JSON.parse(value) as T;
+  } catch {
+    return JSON.parse(sanitizeJsonString(value)) as T;
+  }
 }
 
 export function normalizeOutputs(outputs: Array<{ amount?: string | number; target?: OutputTarget }> | undefined): NormalizedOutput[] {