fix(client): correct HELLO modules reply type (redis#3411)

* fix(client): correct HELLO modules reply type

* fix(client): type HELLO modules entries like MODULE LIST

Author: abhijeet117

packages/client/lib/commands/HELLO.ts

@@ -17,7 +17,11 @@ export type HelloReply = TuplesToMapReply<[
   [BlobStringReply<'id'>, NumberReply],
   [BlobStringReply<'mode'>, BlobStringReply],
   [BlobStringReply<'role'>, BlobStringReply],
-  [BlobStringReply<'modules'>, ArrayReply<BlobStringReply>]
+  [BlobStringReply<'modules'>, ArrayReply<TuplesToMapReply<[
+    [BlobStringReply<'name'>, BlobStringReply],
+    [BlobStringReply<'ver'>, NumberReply]
+    /** path and args exist only on Redis 7.0+ */
+  ]>>]
 ]>;
 
 export default {

packages/client/types-tests/hello.types-test.ts

@@ -0,0 +1,38 @@
+/**
+ * Compile-time regression: each entry of the HELLO reply's modules field is a
+ * structured entry (name, ver), not a plain string. The declared reply type
+ * used to label it Array<BlobStringReply>, so consumers had no type-safe
+ * access to the module fields. path and args exist only on Redis 7.0+ and are
+ * intentionally left out of the declared shape, mirroring MODULE LIST.
+ *
+ * Lives outside `lib/` so it is not picked up by the production build /
+ * typedoc. Checked with `npm run test:types -w @redis/client`.
+ */
+import { createClient } from '../index';
+
+type Client = ReturnType<typeof createClient>;
+type HelloReply = Awaited<ReturnType<Client['hello']>>;
+type ModuleEntry = HelloReply['modules'][number];
+
+export function helloModulesAreStructured(entry: ModuleEntry): void {
+    // Mapped (RESP3-style) entries must expose the server's fields.
+    if (!Array.isArray(entry)) {
+        const name: string = entry.name;
+        const ver: number = entry.ver;
+
+        // A module version is a number, not a string.
+        // @ts-expect-error module versions are numbers
+        const notAString: string = entry.ver;
+
+        if (process.env.NODE_ENV !== 'production') {
+            console.log(name, ver, notAString);
+        }
+
+        return;
+    }
+
+    // Flat (RESP2-style) entries stay arrays.
+    if (entry.length < 0) {
+        console.log(entry);
+    }
+}