feat: factor out parseFrameMessage

src/core/getFrameAccountAddress.ts

@@ -1,9 +1,4 @@
-import { HubRpcClient, Message, getSSLHubRpcClient } from '@farcaster/hub-nodejs';
-
-// URL of the Hub
-const HUB_URL = 'nemes.farcaster.xyz:2283';
-// Create a Hub RPC client
-const client: HubRpcClient = getSSLHubRpcClient(HUB_URL);
+import { parseFrameMessage } from './parseFrameMessage';
 
 type FidResponse = {
   verifications: string[];
@@ -20,16 +15,7 @@ async function getFrameAccountAddress(
   { NEYNAR_API_KEY = 'NEYNAR_API_DOCS' },
 ) {
   let farcasterID = 0;
-  let validatedMessage: Message | undefined = undefined;
-  // Get the message from the request body
-  const frameMessage: Message = Message.decode(
-    Buffer.from(body?.trustedData?.messageBytes ?? '', 'hex'),
-  );
-  // Validate the message
-  const result = await client.validateMessage(frameMessage);
-  if (result.isOk() && result.value.valid && result.value.message) {
-    validatedMessage = result.value.message;
-  }
+  const validatedMessage = await parseFrameMessage(body);
   // Get the Farcaster ID from the message
   farcasterID = validatedMessage?.data?.fid ?? 0;
   // Get the user verifications from the Farcaster Indexer

src/core/parseFrameMessage.ts

@@ -0,0 +1,27 @@
+import { HubRpcClient, Message, getSSLHubRpcClient } from '@farcaster/hub-nodejs';
+
+// URL of the Hub
+const HUB_URL = 'nemes.farcaster.xyz:2283';
+// Create a Hub RPC client
+const client: HubRpcClient = getSSLHubRpcClient(HUB_URL);
+
+/**
+ * Given a frame message, decode and validate it. If message is valid,
+ * return the message. Otherwise undefined.
+ * @param body The JSON received by server on frame callback
+ */
+async function parseFrameMessage(body: { trustedData?: { messageBytes?: string } }) {
+  let validatedMessage: Message | undefined = undefined;
+  // Get the message from the request body
+  const frameMessage: Message = Message.decode(
+    Buffer.from(body?.trustedData?.messageBytes ?? '', 'hex'),
+  );
+  // Validate the message
+  const result = await client.validateMessage(frameMessage);
+  if (result.isOk() && result.value.valid && result.value.message) {
+    validatedMessage = result.value.message;
+  }
+  return validatedMessage;
+}
+
+export { parseFrameMessage };