fix: unify reasoning tags + agent ids (#1613) (thanks @kyleok) (#1629)

src/shared/text/reasoning-tags.ts

@@ -0,0 +1,61 @@
+export type ReasoningTagMode = "strict" | "preserve";
+export type ReasoningTagTrim = "none" | "start" | "both";
+
+const QUICK_TAG_RE = /<\s*\/?\s*(?:think(?:ing)?|thought|antthinking|final)\b/i;
+const FINAL_TAG_RE = /<\s*\/?\s*final\b[^>]*>/gi;
+const THINKING_TAG_RE = /<\s*(\/?)\s*(?:think(?:ing)?|thought|antthinking)\b[^>]*>/gi;
+
+function applyTrim(value: string, mode: ReasoningTagTrim): string {
+  if (mode === "none") return value;
+  if (mode === "start") return value.trimStart();
+  return value.trim();
+}
+
+export function stripReasoningTagsFromText(
+  text: string,
+  options?: {
+    mode?: ReasoningTagMode;
+    trim?: ReasoningTagTrim;
+  },
+): string {
+  if (!text) return text;
+  if (!QUICK_TAG_RE.test(text)) return text;
+
+  const mode = options?.mode ?? "strict";
+  const trimMode = options?.trim ?? "both";
+
+  let cleaned = text;
+  if (FINAL_TAG_RE.test(cleaned)) {
+    FINAL_TAG_RE.lastIndex = 0;
+    cleaned = cleaned.replace(FINAL_TAG_RE, "");
+  } else {
+    FINAL_TAG_RE.lastIndex = 0;
+  }
+
+  THINKING_TAG_RE.lastIndex = 0;
+  let result = "";
+  let lastIndex = 0;
+  let inThinking = false;
+
+  for (const match of cleaned.matchAll(THINKING_TAG_RE)) {
+    const idx = match.index ?? 0;
+    const isClose = match[1] === "/";
+
+    if (!inThinking) {
+      result += cleaned.slice(lastIndex, idx);
+      if (!isClose) {
+        inThinking = true;
+      }
+    } else if (isClose) {
+      inThinking = false;
+    }
+
+    lastIndex = idx + match[0].length;
+  }
+
+  if (!inThinking || mode === "preserve") {
+    result += cleaned.slice(lastIndex);
+  }
+
+  return applyTrim(result, trimMode);
+}