/** * Strict structural validator for `PickedElementPayload` messages received * from the in-page picker preload (`apps/desktop/src/preview/PickPreload.ts`) * via `wc.ipc`. Lives in its own electron-free module so the validator is * trivially unit-testable. * * Validation must be tight: downstream `normalizeElementContextSelection` * calls `.trim()` on incoming strings, so a malformed payload (preload bug, * future schema mismatch, malicious page that intercepts the preload's IPC * channel via prototype pollution) would otherwise throw deep in the * renderer and the chip silently never appears. */import type { PickedElementPayload, PreviewAnnotationPayload } from "@t3tools/contracts"; function isStringOrNull(value: unknown): value is string | null {  return value === null || typeof value === "string";} function isFiniteNumberOrNull(value: unknown): value is number | null {  return value === null || (typeof value === "number" && Number.isFinite(value));} function isPickedStackFrame(value: unknown): boolean {  if (typeof value !== "object" || value === null) return false;  const frame = value as Record<string, unknown>;  return (    isStringOrNull(frame["functionName"]) &&    isStringOrNull(frame["fileName"]) &&    isFiniteNumberOrNull(frame["lineNumber"]) &&    isFiniteNumberOrNull(frame["columnNumber"])  );} export function isPickedElementPayload(value: unknown): value is PickedElementPayload {  if (typeof value !== "object" || value === null) return false;  const c = value as Record<string, unknown>;  if (typeof c["pageUrl"] !== "string") return false;  if (typeof c["tagName"] !== "string") return false;  if (typeof c["htmlPreview"] !== "string") return false;  if (typeof c["styles"] !== "string") return false;  if (typeof c["pickedAt"] !== "string") return false;  if (!isStringOrNull(c["pageTitle"])) return false;  if (!isStringOrNull(c["selector"])) return false;  if (!isStringOrNull(c["componentName"])) return false;  if (c["source"] !== null && !isPickedStackFrame(c["source"])) return false;  if (!Array.isArray(c["stack"])) return false;  if (!c["stack"].every(isPickedStackFrame)) return false;  return true;} function isRect(value: unknown): boolean {  if (typeof value !== "object" || value === null) return false;  const rect = value as Record<string, unknown>;  return ["x", "y", "width", "height"].every(    (key) => typeof rect[key] === "number" && Number.isFinite(rect[key]),  );} function isPoint(value: unknown): boolean {  if (typeof value !== "object" || value === null) return false;  const point = value as Record<string, unknown>;  return (    typeof point["x"] === "number" &&    Number.isFinite(point["x"]) &&    typeof point["y"] === "number" &&    Number.isFinite(point["y"])  );} export function isPreviewAnnotationPayload(value: unknown): value is PreviewAnnotationPayload {  if (typeof value !== "object" || value === null) return false;  const annotation = value as Record<string, unknown>;  if (typeof annotation["id"] !== "string") return false;  if (typeof annotation["pageUrl"] !== "string") return false;  if (!isStringOrNull(annotation["pageTitle"])) return false;  if (typeof annotation["comment"] !== "string") return false;  if (typeof annotation["createdAt"] !== "string") return false;  if (annotation["screenshot"] !== null) return false;   const elements = annotation["elements"];  if (!Array.isArray(elements)) return false;  if (    !elements.every((entry) => {      if (typeof entry !== "object" || entry === null) return false;      const target = entry as Record<string, unknown>;      return (        typeof target["id"] === "string" &&        isPickedElementPayload(target["element"]) &&        isRect(target["rect"])      );    })  ) {    return false;  }   const regions = annotation["regions"];  if (!Array.isArray(regions)) return false;  if (    !regions.every((entry) => {      if (typeof entry !== "object" || entry === null) return false;      const target = entry as Record<string, unknown>;      return typeof target["id"] === "string" && isRect(target["rect"]);    })  ) {    return false;  }   const strokes = annotation["strokes"];  if (!Array.isArray(strokes)) return false;  if (    !strokes.every((entry) => {      if (typeof entry !== "object" || entry === null) return false;      const target = entry as Record<string, unknown>;      return (        typeof target["id"] === "string" &&        typeof target["color"] === "string" &&        typeof target["width"] === "number" &&        Number.isFinite(target["width"]) &&        Array.isArray(target["points"]) &&        target["points"].every(isPoint) &&        isRect(target["bounds"])      );    })  ) {    return false;  }   const styleChanges = annotation["styleChanges"];  if (!Array.isArray(styleChanges)) return false;  if (    !styleChanges.every((entry) => {      if (typeof entry !== "object" || entry === null) return false;      const change = entry as Record<string, unknown>;      return (        typeof change["targetId"] === "string" &&        isStringOrNull(change["selector"]) &&        typeof change["property"] === "string" &&        typeof change["previousValue"] === "string" &&        typeof change["value"] === "string"      );    })  ) {    return false;  }  return true;}