refactor: share open allowFrom config checks

extensions/shared/config-schema-helpers.ts

@@ -0,0 +1,25 @@
+import type { z } from "zod";
+
+type RequireOpenAllowFromFn = (params: {
+  policy: unknown;
+  allowFrom: unknown;
+  ctx: z.RefinementCtx;
+  path: string[];
+  message: string;
+}) => void;
+
+export function requireChannelOpenAllowFrom(params: {
+  channel: string;
+  policy: unknown;
+  allowFrom: unknown;
+  ctx: z.RefinementCtx;
+  requireOpenAllowFrom: RequireOpenAllowFromFn;
+}) {
+  params.requireOpenAllowFrom({
+    policy: params.policy,
+    allowFrom: params.allowFrom,
+    ctx: params.ctx,
+    path: ["allowFrom"],
+    message: `channels.${params.channel}.dmPolicy="open" requires channels.${params.channel}.allowFrom to include "*"`,
+  });
+}