feat(discord): support forum tag edits via channel-edit (#12070) (thanks @xiaoyaner0201)

src/agents/tools/common.ts

@@ -1,7 +1,7 @@
-import fs from "node:fs/promises";
 import type { AgentTool, AgentToolResult } from "@mariozechner/pi-agent-core";
-import { detectMime } from "../../media/mime.js";
+import fs from "node:fs/promises";
 import type { ImageSanitizationLimits } from "../image-sanitization.js";
+import { detectMime } from "../../media/mime.js";
 import { sanitizeToolResultImages } from "../tool-images.js";
 
 // oxlint-disable-next-line typescript/no-explicit-any
@@ -273,3 +273,41 @@ export async function imageResultFromFile(params: {
     imageSanitization: params.imageSanitization,
   });
 }
+
+export type AvailableTag = {
+  id?: string;
+  name: string;
+  moderated?: boolean;
+  emoji_id?: string | null;
+  emoji_name?: string | null;
+};
+
+/**
+ * Validate and parse an `availableTags` parameter from untrusted input.
+ * Returns `undefined` when the value is missing or not an array.
+ * Entries that lack a string `name` are silently dropped.
+ */
+export function parseAvailableTags(raw: unknown): AvailableTag[] | undefined {
+  if (raw === undefined || raw === null) {
+    return undefined;
+  }
+  if (!Array.isArray(raw)) {
+    return undefined;
+  }
+  const result = raw
+    .filter(
+      (t): t is Record<string, unknown> =>
+        typeof t === "object" && t !== null && typeof t.name === "string",
+    )
+    .map((t) => ({
+      ...(t.id !== undefined && typeof t.id === "string" ? { id: t.id } : {}),
+      name: t.name as string,
+      ...(typeof t.moderated === "boolean" ? { moderated: t.moderated } : {}),
+      ...(t.emoji_id === null || typeof t.emoji_id === "string" ? { emoji_id: t.emoji_id } : {}),
+      ...(t.emoji_name === null || typeof t.emoji_name === "string"
+        ? { emoji_name: t.emoji_name }
+        : {}),
+    }));
+  // Return undefined instead of empty array to avoid accidentally clearing all tags
+  return result.length ? result : undefined;
+}