fix(interceptor): guard XHR double-wrap and thread currentAttr into regex fallback

src/interceptor.js

@@ -14,7 +14,7 @@ export function startRequestInterceptor({ prevValue, currentAttr, onTrain, onPar
   let warnedFor = null;
 
   const handle = (text, url) => {
-    const parsed = parseTrainResponse(text, url);
+    const parsed = parseTrainResponse(text, url, currentAttr);
     if (!parsed) {
       if (warnedFor !== url) {
         warnedFor = url;
@@ -22,7 +22,7 @@ export function startRequestInterceptor({ prevValue, currentAttr, onTrain, onPar
       }
       return;
     }
-    if (parsed.attr !== currentAttr) return;
+    if (parsed.attr && currentAttr && parsed.attr !== currentAttr) return;
     const delta = parsed.newValue - lastValue;
     lastValue = parsed.newValue;
     if (delta > 0) onTrain({ attr: parsed.attr, delta, ts: Date.now() });
@@ -36,7 +36,7 @@ export function startRequestInterceptor({ prevValue, currentAttr, onTrain, onPar
   };
 }
 
-function parseTrainResponse(text, url) {
+function parseTrainResponse(text, url, fallbackAttr) {
   // Try JSON
   try {
     const j = JSON.parse(text);
@@ -48,20 +48,21 @@ function parseTrainResponse(text, url) {
     }
   } catch { /* not JSON */ }
 
-  // Fallback: scan text for a number formatted like an attribute.
+  // Regex fallback: scan text for a number formatted like an attribute.
+  // If we find one and the caller passed a fallbackAttr, use it; otherwise
+  // the caller can choose to ignore the result.
   const m = text.match(/(\d{1,3}(?:,\d{3})+|\d{4,})/);
   if (m) {
     const newValue = parseInt(m[1].replace(/,/g, ''), 10);
     if (Number.isFinite(newValue) && newValue > 0) {
-      // Without a confirmed attr, fall back to whatever currentAttr
-      // the caller passed in.
-      return { newValue, attr: null };
+      return { newValue, attr: fallbackAttr || null };
     }
   }
   return null;
 }
 
 function wrapXhr(handle) {
+  if (XMLHttpRequest.prototype.send.__tatWrapped) return;
   const origOpen = XMLHttpRequest.prototype.open;
   const origSend = XMLHttpRequest.prototype.send;
   XMLHttpRequest.prototype.open = function (method, url) {
@@ -74,6 +75,7 @@ function wrapXhr(handle) {
     });
     return origSend.apply(this, arguments);
   };
+  XMLHttpRequest.prototype.send.__tatWrapped = true;
 }
 
 function wrapFetch(handle) {