Improve types/documentation.

Signed-off-by: Eric Peterson <ericpeterson@spotify.com>

plugins/techdocs-backend/src/DocsBuilder/builder.ts

@@ -221,7 +221,7 @@ export class DocsBuilder {
     });
 
     // Invalidate the cache for any published objects.
-    if (this.cache && published?.objects?.length) {
+    if (this.cache && published && published?.objects?.length) {
       await this.cache.invalidateMultiple(published.objects);
     }
 

plugins/techdocs-backend/src/cache/cacheMiddleware.ts

@@ -100,7 +100,7 @@ export const createCacheMiddleware = ({
     // Monkey-patch the response's socket to keep track of chunks as they are
     // written over the wire.
     socket.write = (
-      data,
+      data: string | Uint8Array,
       encoding?: BufferEncoding | ErrorCallback,
       callback?: ErrorCallback,
     ) => {